modified intake port
intake manifold with 4 runners
A cam converted to sort of fit a T block with my "radical" grind
closer shot of the lobe
notches filed into the front and centre cam bearings to permit installation of this cam
How do you like this Model T cam grind ?
very impressive. I assume it is in your 2 up 2 down engine and I assume uses roller lifters. Does anyone have the masters to make more copies of it?
How was the engine for "drivability"?
I'm guessing that it wasn't much for idle?
The cam I have shown I have the masters for and actually makes a very nice drivable engine. I have never "dynoed" the engine, but it feels like about 60 HP. Pulls hard to 4200 rpm where the valves float with T springs. Has good torque down to about 1500 rpm
Very nice fabrication work. I'm guessing you replaced the rods with something stronger than babbit bearings?
Nice work. Gonna be a good runner I imagine.
Counterbalanced A crank drilled for pressure oil. A rods. Babbitted bearings No problems at 40-45 psi oil pressure
OK, that's radical. Dave in Bellingham, WA
Yes Les it's the two up two down block as found at Chris's barn.
Les, What type of ignition do you use to operate at 4200 RPM?
So far ordinary distributor. Actually it is a Vega distributor with the standard automatic advance mechanism. I've considered a e timer
The E-Timer will only provide automatic timing advance up to about 3600 RPM operating on 12VDC then start retarding timing so distributor may be the best option for you.
It may be possible to make a custom version that decreases the coil charge interval to permit higher RPM but that would make a weaker spark more vulnerable to fouling.
Frank, could you give some more details on the two up two down motor? I have heard about it in the past and would like to know more about it and some history of the car would much appreciated.
Les is is the grind n the A cam steeper then an Edelbrock full race that Clayton and I use in in the Special and Joesphine his Black roadster. Clayton use a stock T cam and I use the modified A cam like you show in your block. Could I send you an a cam and have that agree subs find out on itand what mods would I have to do to my block to use it. I am trying to beat clay power wise in flat head rather then putting an overhead on it!😎
We are changing out the head from a Reeder to a planed Z head and changing the induction from a Stomberg 97 and single Model intake to a Zephyr Or Thomas intake with a single modified 81.
The grind fits fine onto a stock A "doner cam", which is what you see in the picture. I don't know if it is "steeper" and I can not make any worthy comment on the Edelbrock cams you mention as I have never seen or touched them. What I will say is that the profile has been tried without the intake port dividers by a couple of guys and the results were not "satisfactory" at anything other than high RPM. So this implies to me that the duration is quite long. Which means that you will have #1 intake valve still substantially open when #2 starts to open. By having this condition, you lose the "ramming" benefit that you get from the divided intake runners. I should point out that runners are divided substantially all the way back to the carburetor area.
I will further qualify that the guys who tried this profile were also running fairly stock compression.
Anyway if you ship me your cam I will try to compare the profiles and lobe timing. I have a degree wheel that I can attach to it and put a dial indicator to the lobe and "build" a chart and compare the two cams. If the variance is significant, I can then offer you the opportunity to get yours reground if you so choose.
Another option that could save you some money is that you degree and measure your cam yourself and I can do mine and we can compare results
On a further note regarding cam installations, I think the variable cam gear that Stipe offers a significant potential. On the engine I have described I just installed the cam as close to "straight up" as I could and it worked. I suspect that there may have been quite a bit of "luck" involved
Cylinder head; I like the Sherman and Prus combustion chambers as they closely resemble the shape that Ford used on the V8 in '33-35. The Z head resembles the Ford B head of '32. Ford changed for a reason I believe. Ultimately Ford changed the shape again by '37 and retained that until the end of their flathead production. I Have a T engine in process that is using that chamber shape with pistons to suit. I have not run it yet. My research indicates that piton head clearance should ideally be in the .030-.060 range to achieve good flame quench to maximize HP and minimize detonation. I am not sure you will achieve this easily with a Z head.
I will add that the engine using the cam you see, uses a Stromberg/Holley 94. It has a Watts clutch. It has sufficient torque that if you "stand on it" at 1500 rpm in high gear, the clutch slips. By 2500 RPM the clutch will hold. I figured it was a advantage to have this "torque limiting" feature to help the rear axle to survive. The T rear axle has Timken tapered roller pinion and needle roller thrust washers.
I hope this all helps you