Which works better a 270 reground cam or a 280 high performance cam? What have you experienced after you up-graded?

Happy motoring,

Warren

Hi Warren,

I'm not out to bad mouth anyone! I ran a 270 regrind for 5 yrs. before replacing it with a 280 cam. A close friend at work was also using a 270 regrind for some time in his 12 roadster. He ended up replacing it with an early original cam.

The reason both of us replaced the 270 regrind cam was because it performed much worse on hills compared to other T's with stock cams. On the flat, the 270 performed great. With out changing any other item or changing adjustments .....both of us found that after replacing the 270 regrind cam with a 250 "stock" or 280 cam our model T's now performed much better on hills.

I made many changes and lots of adjustments (Carb, timer, coils) before putting in the 280 cam. Sever people told me it was not the 270 cam but it was something else. Right after putting in the 280 cam, we went on an Estes Park model T tour and got a lot of time testing our 13 touring against many other model T's on hills and flat areas. I passed more T's going up Trail Ridge than I have fingers and toes. Not a show off...or driving un-safe, just did not want to get bogged down following other slower cars on hills. We have all been there!

I now have almost 10 yrs. on the 280 cam and am very happy that I made the change. I have walked the walk! Those that want to can go on thinking up reasons why the 270 regrind cam did not perform well on hills and that it was something else as the cause....However, how do you explain the change in performance on hills on 2 different model T's when no other changes or modifications were made.

Installing the 280 cam in my 13 engine required removing some material under the block to gain adequate tappet clearance. With out doing so, the top side of the tappet face would bind against the block. I under stand most engines have enough clearance for the increased lift. I my case it caused me a lot of work to install the 280 cam. For me, it was well worth the effort.

Good luck!

Thanks Les, great to get your thoughts on the difference using both cam. My very good friend Ken has a 280 and says it performs great. That may be the best way to go.

Happy motoring,

Warren

Warren,
Some time ago, someone posted they had a 250 lift in one of their T's and a 280 lift in another and the 250 pulled a little stronger on hills. Unless you compare it in the same car (Weight/Engine Condition).....not sure I would make my decision on that post.
Take a look at the data found under Model T Cam Project that the Tulsa group performed. Very impressed with the work that they did. Also good comparison's on different heads. Their finding's and what I experienced is why I'm running a 280 lift.

Les, Warren, It is true, the stock Model T cam has slightly better low end performance at 0.015 Valve clearance than the Stipe 280. AS to the 270 grind, whose 270 grind did you use? Our old 270 grind produced prior to 2002 had a very good high end but did not meet our expectations at the low end. when we designed our new 280 grind we learned a lot about cam design and also redesigned our 270 Driver grind. around 2002 we started producing the new 270 grind that performs as well as Stipes new 280 grind at a much lower cost. The new 270 grind is very popular and people rave about it's performance. Our new 280 grind is even slightly better. I have the specs available if interested. Glen

Hi Glen,
The 270 grind cams that I discussed were both purchased from you prior to 2002. Now knowing that you changed the design of your 270 grind cam from what we purchased helps me better understand why customers today have greater success than what we had. We both were very unhappy with the 270 cams we purchased from you. I am very happy with the other model T parts that you have provided me over the years and it has been a pleasure dealing with you. Enjoyed the tour of your latest digs....Smile.
Thank you for responding and clearing up an issue that has bothered me for a long time.

Les

Thank you Les. I wish you had talked to me about this issue before. We make a great effort to supply the best available. Prior to 2002 we were using the cam masters of the cam grinder. We had no other choice and relied on the cam grinder. However, that cam was designed to give a better high end and the low end suffered. After we started studying cam design it became obvious that we needed to make a change for general Model T driving. . So we had new cam masters made to our specifications. In our study we determined what parameters worked best to give the Model T both a good low end and a good high end. That was a difficult task but we succeeded. The results were a significant improvement in our cams. I doubt if any additional improvement could be made. Nothing is more important to us than having happy customers. That has always been our goal.

Glenn, Not to throw a wrench into this thread, but what about people who are advancing the cam and why.
George n L.A.

George, Advancing the Stock Model T cam and the Stipe 280 cam 7.5 deg will improve the high end performance. Our 270 driver cam performance can be improved on the high end by advancing it 6 deg. 7.5 deg is too much. Our new 280 cam needs no advance. It is already advanced to the optimum point which is 2 deg ATDC.

Glen,
According to your last post....Advancing the Stipe 280 cam 7.7 deg will improve the high end performance....what will it do to the low end?

Glen, What cam would you think would best on a roof BB head. thanks Ross

Les, Advancing the Stipe 280 cam 7.5 deg improves the high end torque 1.436% and Horse Power 1.648%. Low end torque is improved 0.25% and Horse power, no change.
Ross, We recommend our new 250 cam for overhead use. There is no need for additional lift. But, you could also use our new 280 cam. The 250 cam has slightly better low end and slightly less high end than the 280 cam.

Glen thanks for the info not ready yet just gathering info till I get all the parts I need for the head. thanks Ross

The reground 270 sounds like the best option for me, as I am more interested in hill climbing than high speed. Thirty five miles per hour suits me just fine. "The Driver Grind (270) is Designed For Touring Applications Where Good Low End
Torque For Climbing Hills And Improved Performance
At Moderate High Speeds Is Desired. Cam Specifications Are Available." Thank you Glen and all the rest for joining in on this discussion.

Happy motoring,

Warren

PS: https://www.youtube.com/watch?v=2DC2c0jm-BU

video made going up Mill's Hill (NH Route 13) in Dunbarton, New Hampshire is a 1.6 mile climb and 8% grade

Warren, She's really pulling that hill good, just like my original 1913 roadster. It pulls most any hill in high gear picking up speed. A good cam can really make a difference.

Since most readers are probably not aware, I want to make sure they understand that the performance figures
Glen quotes are based on a computer engine simulator not real head to head comparisons on a dyno. These programs are useful, but the numbers they produce are only approximate. From my experience I would never quote simulator results that a cam produces 1.436% more power. That implies the values are accurate to 0.001 horsepower. Sorry, I don't buy that. Your lucky if they are accurate to 2 to 3 horsepower.

A good review of accuracy versus precision:

http://www.mathsisfun.com/accuracy-precision.html

No dyno, computer or engine is 100% accurate. Engine dynos will vary from one run to the next. They are subject to variations due to the weather,the atmosphere and many other variables. when a computer dyno has been configured to produce the Ford advertised performance of the Ford cam it is pretty accurate That is what we did and the results are always the same because it is not affected by the variables mentioned. Once you have the computer dyno configured you have a valuable tool because you can put in any cam parameters and compare the results with the original Ford cam or any other cam. The actual performance may not be 100% accurate but it is close and all tests performed have the same inaccuracies so it makes it a good indicator when comparing cam performance or the results of advancing the cam or changing other parameters. Actual road tests have proven this to be correct. Mike Bender has been trying to run motor dyno tests on all the available cams but has had too many problems to get any good results so far. Hopefully he will be able to correct those problems.

Larry,

What have you experienced/knowledge using a Stipe 280 cam with an advanced timing gear? I am building up another engine (Much Better 13 Block) for our 13 touring. Was planning on using my existing 280 Stipe cam that I have been running for 10 yrs. from my old engine. I have a new nylon advanced timing gear from Lang's and was planning on using it in my new build. What's your recommendation? I am interested in any gain on the low end. As for the high end.....it goes faster than I want to drive.
I have a new Z head for the new rebuild. Have been running a Giant cast iron performance head and have been very happy with that set up. Compression is lower for the Giant head compared to the Z head. Also, adding a Scat crank. New hard valve seats installed on all valves.

Have been using synthetic 10-30 oil for 15 yrs. and have not needed to adjust any bearing shims. Also have 1/2" oil line from the hogs head to pan for extra oiling. No magnets or slinger on flywheel for 15 yrs. Just sharing what has worked for me.

Newbie question here - is there such a thing as a break-in procedure for Model T camshafts?

On the Mopar V8s that I've rebuilt, we always take them up to 1500-2000 rpm immediately after startup and let them run there (varying the speed in that range every few minutes) for a total of 20 minutes. This gives plenty of splash oiling to get the lifters to spin in their bores and "break in" the cam.

My experience has been that by the time the cam break-in is complete, the rings are well on their way to being seated as well.

Les, See my Jan 12 post above regarding advancing the Stipe cam.

Mark, Our new cams have a break in lubricant applied to all lobes. You simply install the cam and use it normally. We also have a break in lubricant in a tube.

No one is talking about the Stipe 290 lift flat head cam. I am no cam expert, but I've been told that the 290 is the best. Some are saying that Stipe is not making any more cams. If true, then Glen is our provider.
So now Glen, If 290 lift is better, why isn't your new cam 290 lift?

Hi Fred, The computer dyno shows a big difference between most cams. However, the dyno shows little difference between the 290 and 280 cams. I may have the wrong specs for the 290. Do you have the correct timing specs? If so, please send them to me. thanks Glen

Glen, do your 270 regrind cams require a break in lubricant? Joe

Glen,
What evidence do you have to back up the statement:

"The actual performance may not be 100% accurate but it is close and all tests performed have the same inaccuracies ...."

That is an assumption based on poor logic.

Also, SAE has worked out accurate formula to account for variations in atmospheric conditions.
Larry

“Stock Cams”
The way everyone talks about cam lift, you would think that is the only thing that matters. In fact, it is less important than all four of the cams timing events, which are: (intake open (BTC), intake close(ABC), exhaust open (BTC), exhaust close ATC). Here are some example numbers (note -13 BTC means 13 degrees after top center). The most important timing number is the intake closing, since that determines how much fuel/air is trapped in the combustion chamber. Normally, but not always, a later intake closing will help at high RPM, but hurt the low end.
Here are some numbers for several cams with 250 lift that are called “stock”, “modified stock”, etc.
Ford NOS: -13, 51, 38, 0
Stipe: -12, 52, 39, 1
Chaffin: -5, 55, 33, 17 (original)
Chaffin: -2, 49, 38, 9 (modified)
Stock (regrind): -2, 61, 48, 11
First, note that the Stipe cam is basically the same as Ford stock. The first Chaffin cam listed has the specs from the document Glen distributed a few years ago. These numbers were verified by direct measurements. Since that time Glen tells me he changed his cams to the modified numbers by advancing the cam 4 degrees and reducing the lobe separation from 109 to 110 degrees. Those changes should definitely improve the cam in my opinion, since intake closing and exhaust opening are very close to those of a stock cam. The intake opening and exhaust closing difference of about 10 degrees should not have a major impact on performance, except possibly at idle and off idle, due to the overlap. The last cam is a stock cam which was reground to restore its lift. The lift was still only 0.242 and the duration increased by 20 degrees, so openings are 10 degrees early and closings are 10 degrees later. It is ridiculous to call this a stock cam.

Advancing a Cam
Consider what happens when you advance a cam half a tooth (7.5 degree).
Ford Stock : -5, 43, 45, -7 (advanced 7.5)
Stock (regrind): 5, 53, 55, 3 (advanced 7.5)
All four events occur earlier, but the intake valve closing is usually the most important event and closing it sooner should improve low end performance. The improvement will be most notable for the reground cam, because its closing is very late if the cam is not advanced. The other point to notice is that the exhaust valve is also opening earlier. If the cam is advanced too much, the exhaust valve will open before all of the power is absorbed out of the charge. In my opinion, advancing a reground cam or a cam with long duration makes sense. Advancing a stock cam, Stipe cam or Chaffin cam makes less sense. I would guess that something like four degrees might be reasonable, but only an accurate dyno test (a real dyno not a computer dyno) will settle this matter.

One problem with advancing a cam is that all the lobes move together. It would be better to advance the exhaust lobe to a lesser degree than the intake lobe. That is the way the new Stipe 290+ cam is designed, the intake lobe is advance 7 degrees, but the exhaust lobe is only advanced 2 degrees. This cam also has a quick opening profile, so it achieves almost 0.300 lift with less duration than the 280 cam.

290+ Cam
The timing numbers for the 290+ cam compared to the Stipe 280 are as follows:
Stipe 290+: -6, 44, 46, 4
Stipe 280: -10, 54, 45, 7
The advance on the intake is more pronounced than on the exhaust. The difference in this cam is the timing not the lift. Lift is always less important than timing. Model T cams are the only cams I’ve seen advertised where only the lift specification is given.

Glen said:
"Advancing the Stock Model T cam and the Stipe 280 cam 7.5 deg will improve the high end performance."

Glen makes this statement again based on his computer program. This is a case in point. In previous posts, Tom Carnegie, Mike Walker and others stated this is backwards. It makes no sense. So much for the accuracy of the computer dyno.

Thank you Larry for taking the time in posting the cam comparisons. I was encouraged to buy a Nylon advanced timing gear after talking to Gen 111 several years ago. He claimed the advanced timing gear worked well using a Stipe 280 cam in engines he was rebuilding. At the time, I also talked to Bill Stipe for guidance. His advice was to try his new 290 cam....he did not have any data using the advanced timing gear with a 280 cam. He knew some were doing it but did not have any actual dyno data.

I will error on the side of caution and use a standard timing gear with the Stipe 280 cam that I have been using. At least I know from usage....this works. After having several bad experiences with past modified cams.....I do not want to be "Stung" again. New cams are expensive and I do not enjoy changing them once the engine is in the car.

Larry, Thank you for the Stipe 290 specs. In regards to your opinion about computer dyno's. Everyone is entitled to their opinion. I do not know what you are referring to with regards to Tom Carnegie and Mike Walker but that doesn't prove that a computer dyno cannot be right. While the absolute numbers may not be perfectly accurate, they are close when the dyno is configured correctly and the comparison numbers between cams is pretty accurate because they all contain the same errors. I have sent you copies of some of our data so you can see what I mean. The data for a stock Ford cam is very close to the Ford published performance specs. This tells me that the computer dyno that we are using is pretty accurate. Our customers are very pleased with both our new cams and our driver regrind so we must have done something right. The computer dyno is a great tool in determining very quickly what works and what doesn't. It is difficult to argue with success. In your second post above you state that the Stipe 280 cam valve timing events are -12, 52, 39 and 1. in your forth post you state that it is -10, 54, 45 and 7. I assume that the latter is correct ?

Les -- The Stipe 280 with the advanced gear works great. Go for it!

Mike. I agree. Contrary to what Larry young says advancing the Stipe cam will improve its performance. That's exactly one of the things we did for our new 280 cam and it works quite well in spite of all the neysayers. They also told me that reducing the cam lobe center angle was a bad idea but they were wrong and Stipe has now reduced the lobe centers of his new 290 cam. The Stipe 280 cam is a good cam but it can be improved.

After sleeping on it I realized that any comment made by Tom Carnegie or Mike Walker would be irrevalent because these guys are only interested in high speed for the Montana 500. Designing a cam for their use would be entirely different. In fact we have helped other people design cams for that application. But the cams we offer are for general street use and have both a good high end and a good low end. That is what the normal Model T owner wants and that is exactly what we offer.

Glen,
This first post is for 250 cams. The 4th post is for the 280 cam. You have stated above and in other posts that your computer program says advancing the cam improves the high end with some loss at the low end. Common sense and experience says that is wrong. If the program were any good it would show the same thing..

So Glen, you're wanting to retire, I can't imagine why...

Let me say a few more words about cam advance. The stock model T cam has a 115.3 degree lobe separation (in cam degrees). If it were installed straight up (no advance or no retard), the center of the intake and exhaust lobes would be a 115.3BTC and 115.3ATC. Ford’s installation retards it 6.4 degrees so the intake is at 121.7ATC and the exhaust is at 108.9BTC. It is pretty common for a low RPM engine to run best with the cam retarded, since almost all of them did. The Stipe 250 and 280 are installed in the same way, because we knew the computer dyno program wasn’t accurate and we knew Ford had done considerable testing to establish these specs. Since that time, I have researched the entire history of flathead cam design and have been involved in designing several special cams for different types of racing.

The lobe separation of 115.3 for the Model T compares to 111.5 for the Model A, 114 for Model B and (32-36) V8, 111.5 (37-48) V8, 111 to 110 for later V8s. The advance on these later engines varied from -0.5 to +1.5. We designed the 290 cam to be closer to these later cams with a 113 lobe separation and 2 degrees of retard (or to be determined by dyno).

Glen, with regard to your comments: You originally had a 109 degree lobe separation on you cam and it was set up for 11 degrees of retard. I told you I thought 109 was too small and 11 degrees was too much retard. You have since changed it to 110 separation and 5.5 degrees of retard, which I believe to be more reasonable. You keep stating that your cam is already advanced, but 5.5 degrees of retard is not advanced. The intake opening is only 2 degrees earlier than stock timing and the exhaust closing is essentially the same. These are the two most important timing numbers. If a stock cam benefits from advancing, then very likely yours would also.

Advancing a cam 7.5 degrees is quite a lot. Has anyone tried something less? If 7.5 is optimal, then it says the Ford engineers blew it, big time. I know Trent Boggess has uncovered documents where Ford experimented with timing back in the days of the N,R and S. If I were going to try advancing a stock or Stipe 250 or 280 cam, I think I would try 4 degrees, but I think the 290 cam will be the ultimate answer.

Bill Stipe tells me that he is currently working on a batch of 45 new Model T cams. They should be available in about 2 months.

Glen -- Tom Carnegie is a Montana 500 guy; I've not had the pleasure of attending that event. The improvement in performance I noticed by advancing the cam timing on a Stipe 280 is in hill-climbing capability.

I can tell you that Glens reground 270 made a big difference in all aspects of my 25 coupe. And all for the good.

I too think that advancing a cam generally helps low end, which is pretty much all a T does. That is, 50 mph at 2000 rpm would be considered low end on most engines.

Larry, I do not claim to be a cam design expert and never have. However, I agree You are right, Ford spent a lot of time in cam design and designed a very good cam for the Model T. That is why it is so hard to improve on it. The single most improvement was to reduce valve lash. This considerably improves both the low end and the high end of the cam and is easily seen with our computer dyno. I do not know what computer duno you have used but ours works just fine. I do know that Larry Sigworths computer dyno was not configured properly and would not give you the correct performance for the stock Ford cam. Ours does. With regards to your comments above, the Ford and Stipe 280 cams have 115.5 deg lobe separation, not 115.3. When we talk about advancing the cam we are talking about advancing the opening of the intake valve and the other valve train parameters follow. The intake valve of the 280 Stipe cam opens at 10 deg ATDC. The intake valve of the Stock Ford can opens at 6 deg ATDC with 0.015 valve lash. The intake valve of our original 280 cam opened at 6 deg ATDC. We advanced the cam by 2 deg which advanced the valve timing by 4 deg to 2 deg ATDC. A 4 deg advance. This improved both the high end and low end performance with the most change in the high end. Advancing the Stipe cam 7.5 deg would improve its performance. advancing the stock Ford cam about 4 deg would improve its performance. any more advance would hurt performance. My question to you Larry is have you ever used a computer dyno and if so whose? and if not how can you be so negative about their use. I have found ours to be pretty accurate and quite useful in determining what works and what doesn't. All I know is what I feel when I drive my car. We have a lot of low end torque, can easily climb hills in high gear and I don't have a Ruckstell and can still easily drive 50 MPH on the flat land. What more could you ask for? And it was all made possible by a computer dyno that is no good! We have never had a single complaint about our cams performance except for our early regrinds which occurred prior to 2002 and before we had the dyno. Those cams had too much duration and were only good for the Montana 500. That problem has since been fixed. We have a lot of useful data from our computer dyno and it has worked. What data do you have?

Glenn;
The cam you had with issues, made prior to 2002.... was that your 'driver' or a different cam? I don't recall what all you had at that time. I know you're referring to your 270 cam above, I just don't know if that is the same or different from the one you called your driver at the time.

Glen, I have used the same computer dyno that you and Sigworth have used. It did steer us in the right direction, i.e. toward cams with less duration than the regrinds that were available 15 years ago. However, when we compared them head to head on a dyno, the results did not agree at all. The direction of the difference was correct, but the magnitude of the difference was not even close. I call this a qualitative tool. To refine the results you need a better tool, i.e. a real dyno. I can site numerous examples where the computer dyno predications are not accurate. Maybe you find it to be accurate because you’ve never compared it directly to dyno data on multiple engine configuration.

Why are you so fixated on intake valve opening? That is much less important than intake valve close, due to the small/slow motion when the piston is near TDC. If you are only going to state one number, it should be the intake closing or the intake centerline. The stock T, Stipe 250 or 280 cams are rather retarded at -6.5 degrees. Your original cam specs were retarded -11 degree and after your mods it is at -5.5. It is still rather retarded and does not justify your boasting that it is already advanced (at least not by much). Of course, your longer duration and narrow lobe separation come into play too.

I have also tried to explain to you that you cannot use the dyno program to study valve lash. Since the program only allows you to supply very basic cam data, it will draw its own lift curve through the data. If you adjust the valve lash, you will see the new curve is not a simple shift of the original curve (as it should be), but is instead an entirely different curve. In effect you are comparing two entirely different cams rather the one cam with a different valve lash.

You stated the computer dyno allowed you to climb hills better and reach 50 mph. We got to the same point by just installing a NOS Ford cam.

The 270 cam that I purchased from Chaffin prior to 2002 was called a "Driver Cam". The cam I received was a regrind later style cam. I turned in a good later style core to avoid additional costs. At that time, a Driver 270 cam was priced around $75.00.

One thing we can all agree upon.....Ford engineers that designed the Model T cams were "Sharp" for the time including where we are ....100 years + later.

Larry, Advancing the intake opening is what everyone is talking about with their fixation on advancing the cam 7.5 deg. You know as well as I do that when you advance the cam you advance all of the cam valve timing events equally because the duration and valve lash is fixed. So when you advance the intake valve opening you also advance the intake valve closing. Same holds true for the exhaust. The Stipe cam is retarded with the intake valve opening at 10 deg ATDC. Our cam is advanced at 2 deg ATDC with the intake closing at 49 deg ABDC. Duration 227 deg. Contrary to what you say, the computer dyno can check the effects of valve lash. But you first have to check the change in timing events and duration caused by a change in valve lash in an actual engine before you put this data in the dyno. It then will tell you exactly what the effect on performance is. Larry Sigworth was kind enough to tell me what computer dyno he was using and also gave me his configuration data. However. his configuration would not give me the cam performance published by Ford in 1922. That meant that the program was not configured properly. I do not know if he has corrected this anomaly but I have, and our computer dyno gives us an almost exact match in performance as published by Ford. If the dyno will do that I believe that it is pretty accurate.
True, there is little difference in performance between the stock Ford cam with a smaller valve lash and all of the current new cams. The improvements that have been made are very small and there is little difference between the cams but they do perform better. This has been shown by our computer dyno which also shows that the Stipe 280 cam is a good cam. So why are you condemming our computer dyno? You need to fix your dyno so it performs like ours. You will then have a very useful tool.

Gary, Yes the cam has always been called the driver cam. But prior to 2002 it was different. At that time I did not have my own masters and had to rely on the cam grinder. The master they chose had the lift we wanted but had too much duration. This was a high speed cam but lacked on low end torque and horsepower. At that point we started studying cam design and made changes to correct this problem. The 270 regrind now performs as well as most of the new cams.

Still haven't answered the question. How many folks out there have Chaffin's "new" 270 re-grind driver camshafts in their cars, and what is your opinion of their performance as opposed to a new Stipe 280 grind camshaft? Personally, I have a new Stipe 280 in my 26 Touring. But if I can get roughly similar performance out of a re-grind for my next project and save a wad of cash too, that would leave more funds for the other stuff I need to purchase.

Hey Kevin.
Haven't tried a new Stipe but I have the regrind in my pick up. 30 over aluminum high compression pistons, sway back NH, stock aluminum intake. Stock ring gear.
I live in eastern Ohio pretty hilly country, very seldom have to get into low Ford or Ruckstell. Great low end and half throttle on the flat will cruise 40 to 45. I can get 50 easy full throttle.
From my expirience this is a great combo, I have an OF carb I might try, but I think if it had a more open exhaust I would see even more low end grumt.

We have hundreds of satisfied 270 customers out there and not a single complaint. They all just enjoy their ride. Our new 270 master was produced prior to our getting the computer dyno. The dyno and hundreds of satisfied customers tells us that the 270 is a good cam. However, the dyno also tells us that the 270 performance could be improved a little more by advancing the cam about 6 deg. We are working on a new master that will do just that. The Stipe 280 and 270 regrind have very similar performance. Our new 280 is slightly better. I believe that we have optimized the cam for overall performance. The high end could be improved at the expense Of the low end and the low end could be improved at the expense of the high end but what we have now in the 280 cam is the happy medium for normal driving. Our computer dyno data agrees with the in car performance. All dynos, computer and chassis have errors. I am more concerned with in car performance than I am with the accuracy of absolute numbers. So while the absolute numbers may have some slight errors, who cares. Those errors, if any, are present in the data for all cams tested and all contain the same errors. So, the difference in performance between cams should be pretty accurate. I have found the computer dyno to be a very useful tool in spite of what others say and the results speak for themselves.

Glen,
After following this thread I want to try one of your 270 re-grind cams. I have a half dozen of so camshafts hanging around here and would like to know how does one determine if the cam can be re-ground?

Dean. If you want your cam reground check the bearing diameters to make sure they are not worn too much. original is 0.748 then check the lift. Original is 0.250. Any cam can be reground but it is better to find one that is not worn too much. Thanks, let us know if we can help.

Glen,

I think you have my business too. As soon as I fish the old cam out and check it, I'll give your or Dave a call to find out the return shipping details. By the way, I did order my Ruckstell kit from you guys a couple years ago and know you guys sell quality. Boy! It is sure nice to deal with CNC machined parts compared to old worn out stuff.

Thanks Kevin, we try to please.

I have one of the early 270 cams and plan on going through a refresh on the valves later this year. There's roughly 2500 miles on the old cam. Would your early regrind be an acceptable core for your new grind?

Gary, No, a cam can only be reground once. The lobes would get way too small. How did the old cam perform. Was it lacking a little on the low end? That was our experience.

I tried a couple regrinds, one a 270, and Stipes 280 and 250 billet cams. For me I prefer the Stipe 250 as the best all around cam for hill climbing and speed. If you can find a Ford NOS cam, that is the best low end cam but suffers a bit against Stipes 250 at top end.

Yup, that's the problem. I also have your Driver in my '11 and the performance is definitely different. I've tried to figure out why until now did not know there was a difference in the cams. So it explains the difference.... Both cars have Strombeg OF carbs, both were running Reeder low heads, both have original dogleg manifolds (the aluminum repop manifold I had held the OF against the frame so I put the dogleg on the 15). Both have the same valve setup, but I can't tell you the details, it's been too long. Recently I changed the 15 to HC pistons and original low head, and I'm building up a new engine for the 11 now with HC pistons and will use an original head, so the engines will still be virtually the same, When that's done I will go through and redo the valves on the 15, and will change the cam at that time.

This feels like Rob and Royce all over again!

Gary, the fix for the manifold putting the OF too close to the frame is to put both manifold ports on a belt sander and take just a hair of a wedge off.

Gary S. -- Not even close.

I put a 270 in my 14, Im completely satisfied and put another 270 in the 24 Im restoring. I have no experience with the Stipe cams.

Another happy customer, another happy day for me. Thanks Dan.

Speaking of Royce, where is he? Did I miss something?

Check the MTFCI forum, he has posted there occasionally.

Royce is on a mandated temporary "vacation" from this forum. Haven't you noticed how peaceful it has been without him here?

I sure hope it's just temporary!! Royce is a wealth of knowledge and is a great asset to this forum. Maybe sometimes not everybody agrees on certain issues, but that seems to be normal when you get a bunch of Model T guys together. It's good to see he is on the MTFCI forum and the EFR forum . . . his input on those is an asset to.

I am an electrical guy and knows little about camshaft design. But, as an engineer I believe Larry Young makes a good point above when he stated; "Model T cams are the only cams I’ve seen advertised where only the lift specification is given"
I often wondered who were the original developer of the multiple cam profiles being discussed here and how many being sold by vendors are copies of profiles developed by others?
There are a lot of stories floating around this hobby about that kind of activity.
Ron the Coilman

Ron, We offer all of the information on our cams, Lift, Duration, Valve timing, advance and predicted performance. Always have and always will until I'm six feet under my Model T. Larry Young designed the Stipe cams. I designed our cams and Tom Carnegie designed his own cam for the Montana 500. Most other choices are ground from standard cam Masters designed for other engines that have too much duration and valve timing not suitable for the Model T. Most of those masters were picked for lift and nothing else. I know because I did that before I learned better. Way back then there was no other choice. But today the Stipe and Chaffin cams have been pretty well optomized for use in the Model T for Street driving.

Useful information. Although Larry Young may disagree, here is what our computer analysis shows. 1. The Chaffin 280 cam has been optimized for street use in the Model T ford. 2. Advancing the Stipe cam 7.5 deg will make it virtually as good as the Chaffin cam. 3. Advancing the original Ford cam 7.5 deg will make it much better but not quite as good as the advanced Stipe and Chaffin cams. The low end is about 1.2 % lower and the high end is about 5 % lower. The 270 Driver falls in between the stock advanced Ford cam and the advanced Stipe and Chaffin 280 cams. They all are good cams. Hope this helps

Ralph - I just ordered one of the OF carbs from Stan Howe to replace a self rebuilt NH. I also have one of the AL manifolds which I have painted black so it looks stock. If I have the clearance problem Gary mentioned, which surface do you recommend taking down? Is it the one to which the carb bolts or the one that mounts to the block?

How much advantage would I surrender by just finding another original Ford manifold?

Vintage Paul

Paul, I did it by sanding a taper onto the two surfaces that mount to the block. That's why I used a belt sander, to do them both at the same time. . 1/16 inch taper will give half to an inch of clearance.

Gene Carrothers had to do the same.

I think the idea of sanding the manifold is a perfect solution and would be easy to do....... And a lot less expensive than finding an original aluminum manifold. Either way I'd do what it takes to run the OF he rebuilt for you.

(Message edited by Modeltbarn on January 29, 2015)

OK, I'll figure on finding someone locally who has a belt sander and giving the AL manifold a 1/16" taper. I like the idea of staying with the manifold I have.

Can I remove it without disturbing the exhaust manifold? My old one was badly warped & I would hate to remove it and find out it will need to be replaced a second time.

Vintage Paul

You can if you are careful and make something to hold the exhaust. You can use standard clamps with one end cut off and replace them one at a time, or take some small square tubing and cut 4 pieces a coupe inches long and drill a hole the size of the stud near one end. Either will work to hold the exhaust in place while you remove the intake. Make sure when you sand it to do both ports of the intake at the same time or they will never match, and remember a little bit of taper goes a long way at the other end. 1/16" will make a big difference on where the carb is relative to the frame. I sort of wish I had thought of that before getting rid of my other manifold...... Too late now.

(Message edited by Modeltbarn on January 29, 2015)

I've replaced the intake manifold without disturbing the exhaust much and without making special clamps.

I just loosened the outer clamps first, turned them 90 degrees so they hold the exhaust only, retightened them and loosened the inner clamps so the intake could be switched out. Replaced the inner clamps and tightened them before loosening the outers, turning and retightening them.

I replaced the copper crush washers for the intake to be sure it would seal. No problems with exhaust leaks even though the exhaust manifold was a little looser than normal during the process.

It seems to me that I did something like this when I installed the manifolds. I thought it might be a problem to get everything lined up but didn't turn out to be by using the clamps as you suggest.

I'm looking forward to trying out the OF when it arrives. The car is running pretty good right now but for the muttering or missing out of the tail pipe at idle which everyone who has heard it says is pretty normal.

Vintage Paul

15 Pages so far. Never thought that this subject would stir up so much interest.