Car runs like a scalded dog. Until I blew the head gasket anyway. It's a bit frustrating to ruin a $165 head gasket. I discovered that Olson's Gasket makes them for Langs. They're not open today but I'm hoping to see if they'll make me a gasket with the copper fire ring all the way around the cylinder and exhaust valve cutout.
As you can see there's just not a whole lot of material there between the intake valve seat and the edge of the gasket. Maybe one that just came out further would work.
I was also wondering if I need to make some insert for the intake valve seats that would let the pushrods through, but essentially give me more engine block surface for the head and gasket to seal against.
I have considered having some made out of solid soft annealed copper.
What is your cranking pressure? Maybe it's time to consider O-ringing the block.
looking at your photo, it would seem that the gasket could extend closer to the exhaust valve. That would provide greater sealing surface. Valve plugs with push rod clearance holes could be custom made to fit flush with the block deck. However, that would require a custom made gasket to take advantage of the increased sealing area.
Using the Aircraft grade paint on Permatex may also work. Just a pain getting the old stuff off later.
Install un-machined valve seats or pre-cut seats up side down in the push-rod holes to give the gasket a better surface to seat to.
A variation on Bob's idea is to machine a O ring groove in the block around the old port where the pushrods come up. The groove should be just the right width for a O ring made of "mechanics wire" and about 1/2 of that depth. This is a old trick used by NASCAR and drag race engine builders.
Yes I realize it means probably taking the engine out and taking it to a good automotive machine shop. If you have a seat grinding machine you could probably invent a cutting tool to do it in place
I ran fel pro gaskets from Ford Racing for years on my drag car mustang and i always had head gasket issues because of the compression ratio 13:75 to 1. Now i run a O-ringed block with 400 hp nitrous oxide system and haven't had the heads off in 4 years. The o rings worked for me. Just my opinion! Tim
Upon viewing the above photo, it appears the gasket did not have the same compression as that of the neighboring cylinder. The fire ring on the neighboring cylinder appears much wider. This would imply the surface of the head and / or block was not flat. You may want to check and surface as needed.
Hi Seth for what is worth, I have run Run Sandy Olsons gasket on my 4 valve with no issues. His gasket is made for a 4 valve, it is a composit gasket with a steel fire ring all the way around. works well. It looks like someone modified a standard overhead gasket on yours, without the fire ring it will never work. And yes those 4 valves run well don't they!
Okay, if I burn through another gasket, I'll start looking at and thinking about things like o-rings and all that. Having looked at it and thought about it I think I just need slightly more gasket material there along with a full fire ring.
Mark - I thought the same thing about the flatness but check out the photo - the fire ring is fatter on #1 on the bottom side and skinnier on the top, but the opposite on #2. The fire ring just wasn't very even or consistent comparing the bottom and the top and then from cylinder to cylinder. I'm really confident after tons of eyeballing with a straight edge that both the deck and the head are very flat. The fire rings just aren't equal in material top and bottom.
Mike - I'm gonna see if Olson will make me a gasket with a full fire ring, I think that will really solve my problem. I don't care if it's copper or steel. If need be I'll make a pattern for them from my head.
Also, if you look at this pic, you can see where the gasket just doesn't come out far enough to even take advantage of where the head is. I think if it's just beefed up right there a bit along with a fire ring I should be good to go.
(Message edited by Wreckrod9 on May 27, 2016)
I don't know if I'm saying it very clearly, on this old head gasket the fire rings are probably all the same size, but each cylinder the copper strip wasn't centered top to bottom before it was folded over the edge. So some places there's more folded up on the top and other places more folded underneath.
Regardless, a bit more gasket in the exhaust valve area and a fire ring around the entire piston/exhaust cutout and I think I'll be good to go.
I've searched this a few times and just want to clarify - I'm torquing the head when cold to 50 ft-lbs. I'll let the engine run, and then once it has cooled down completely I check and re-torque to 50 ft-lbs, rinse and repeat until all bolts just stay at 50.
Upon closer inspection it appears that the fire ring did not have any support when located above the old exhaust port for the exhaust valve. That likely caused the gasket to fail in that area. Have you considered putting some plugs in the old exhaust valve port holes? Some have used the head off the stock ford valve to sit in the hole when placing the head gasket.
Sure looks to me that the gasket is a "homemade " conversion of a standard OHV head gasket. The complete lack of fire ring in the valve pocket makes no sense otherwise
I run a solid copper gasket from Kevin Pharis. It looks like your motor may have had oversize intake valves installed, not leaving enough meat under the gasket at that point. I fixed this by installing new valve seats but not cutting them. This leaves a good area for the gasket to seat on an overhead.
Les - this is the head gasket you get when you order one from Lang's for a 4 valve Rajo head. As it came to me straight from them, the fire ring only encircles 3/4 of the cylinder bore. The only difference between the one you see here and the one I got is my fire rings were copper. According to Lang's, this is a specific item they purchase from Olson gaskets, not a homemade conversion.
Mark - if you read my first post that was one of my ideas - possibly making some sort of insert for the engine blocks intake valve seats, so that there is a much larger flat, smooth surface for the head and gasket to seal against. I was wasn't sure how hard they would be to make. Since they'll have to be flush with the deck but won't be supported anywhere except by the valve seat itself.
Andy - how much does a solid copper gasket cost? I was looking at that as an option from either Kevin or from Lubbock gasket that Ed provided the link to above.
OK then I will stick with the "O ring " solution
That head gasket design has more value as scrap than a serviceable part, it will always give trouble with out a full combustion chamber fire ring, no matter what you do to the block!
Here is an old unused asbestos fully copper clad gasket design that worked well.
For all of the uninitiated...I would like to know how you knew that you had blown the head gasket?
My speedster will run unbelievably fast with this Rajo head and dual carbs. 60 mph at 1/4 throttle in Warford overdrive. Then suddenly when I slow down at a stop light she's idling funny, doesn't sound right. I speed the throttle up she runs really rough and sounds terrible and I clearly only have 3 cylinders. You can hear it pretty distinctively - this poof sound of the mixture exploding but escaping the cylinder. I think that my slowing down and using the compression from the engine is what finally blew the head gasket.
It was really odd sounding but it's because the charge was escaping between the head and the block into the block's intake passageway (which aren't functional with this head on) but there's a metal piece covering the intake port where the stock manifold usually goes - it lets you have a surface that mimics having an intake manifold there so that you can still use your normal manifold studs and clamps on the exhaust manifold.
So I have studied the gasket more and I have concluded that if it was my engine I would take some about 3/8" wide copper or brass shim material, anneal it and carefully hand form the rest of the "fire ring". Yes it would probably kill a whole evening and you would probably make a quantity of scrap, but I see no reason it couldn't be done.
I would form a strip into a U channel shape. Then anneal it again and form it around some cutout wooden forms. Probably end up annealing it 3 or 4 times. Only take a minute to heat it up red hot and quench in cold water. Just some thoughts
i think it was common to fill the unused valve ports with babbitt or lead and machine flush to the deck surface ...this would allow a very large shutoff area ...clearance hole for push rod is drilled thru the filled port/seat area ...alwats an optimist...gene french
I have a tool made by Iskendarian cams that cuts the o-ring groove for racing engines. We put o-rings in our T race engine with a 10:1 Gemsa head bored .130" oversize. No way a gasket would last without them. We also use a Kevin Pharis solid copper gasket. Problem is, the tool only cuts an o-ring groove concentric with the cylinder bore. No problem for overhead valve engines. How would you cut an odd shaped groove for a flathead or F-head like the four valve Rajo? I am sure Kevin could make you a solid gasket. It would help to put plugs in the intake ports, but with a good gasket it should be unnecessary. Make sure to re torque the head several times.
Seth, Sorry you are having head gasket problems, But Im paying real close attention to the fixes you make and also the suggestions that are given. I will be putting my 4 valve head on this fall, and hope to learn all I can. If you can get a gasket made with full fire rings I would think that is a good solution and I will also be in need of one. I have two "Fitzgerald" gaskets that came with my 4 valve head, but I want to keep a couple in stock, so I will want to buy another one if they will do them with a complete fire ring. I do not understand why they would even make a gasket without a full fire ring. Here are some pics of the "Fitzgerald" gaskets. They even have the fire ring style edges in the steam holes. Keep us posted ....
Those look good Donnie. I'm pretty confident a solid copper gasket from Kevin or even just a fully copper clad one like yours would do the trick. I think mine only failed because there's not enough purchase right there for a composite gasket without any kind of metal to brace it.
Seth, I think a good gasket will do it. The area where your gasket failed is between two head bolts a long ways apart. And if memory serves, one of those bolts is a long one passing through the Rajo intake port so its clamping pressure is compromised. My experience with these heads taught me a fire ring around the entire chamber is a must, especially if you have boosted the compression ratio as I did with high dome pistons. Auto correct always wants to capitalize Pistons like I am talking about the sports team.
Seth, is it possible you got a odd mistake gasket? It seems to me my gasket from Olson's had a complete fire ring, also I know Olson and he is very knowledgeable with gaskets, surprised he would make one like that intentionally, give him a call, nice guy to talk to and he always makes time for the hobbyist.
Mike I don't think so - the one pictured on Lang's has the same 3/4 fire ring and according to the tech guy I talked to there all of theirs look like that. He did think that they looked very odd but that they don't get much feedback on these - there's just not many folks running this head.
I tried to call Olson's today and they're only open Monday through Thursday.
Honestly the biggest issue for me is $$$. I'm already out $165 for the one I blew. I think solid copper is probably the best option performance-wise and also going to be the most expensive. It will just boil down to what Kevin and Lubbock charge for a solid copper gasket versus what Olson's charges for a fully fire-ringed gasket.
Or maybe Ed or Donnie will sell me one of theirs, lol. I don't really care as long as I can get something that works and slap it back on the car so I can get back to driving again.
Looks like the original gasket never had a fire ring all the way around the chamber, and it seems you confirmed that above. I can't imagine someone would make or sell a gasket like that and expect it to last very long. As soon as the core burns through the gasket is junk. As Andy said, install valve seats flush with the deck and that will solve the support issue. That can be done in the car without pulling the engine if you find a shop with the right tooling. You could o-ring that block on a cnc mill, but its unnecessary with the CR you are running. The gasket without the fire ring is the problem.
Seth, Gene touched on it above. When I was running a 4 valve Rajo I was concerned about the lack of support for the gasket over the old inlet valve seat area. On the few occasions the head was removed the gasket was stressed around that area. I actually fashioned a plug out of the old inlet valve with a hole in the centre to allow pushrod clearance and flattened the top of the valve to be flush with the block surface. The head, and gasket when tensioned down held the plug in place. It worked for me!
That's a really good idea using a old valve with a hole in it. Full marks for ingenuity!!
Is that red RTV all over the head gasket Seth?
I have one of these 4 valve heads. I think Warwick's idea has a lot of merit. I might take it one step further and install the plugs with some aircraft Hysol epoxy.
the pouring full of the intake ports was also done to give a finish appearance to the side of the motor block ...simply dam off the outside intake port with a flat plate ...2 simple cores are machined to fit into the valve guides ...they are tapered to allow removal after pouring ...pour 1 set of tandem ports then the 2nd. set ...the tapered cores form the pushrod holes...remove block off plates from outside of block and machine upper deck and you have a "finished" appearing block with adequate shutoff for a gasket...always an optimist...gene french
Royce it's just copper gasket spray.
Warwick that's exactly what I was trying to ask about in my first post, just wasn't sure how hard it would be to get the valve heads to sit flush and not move, but I'll try that.
Les, I cant take credit for that idea. I read about it in a Fahnestock publication somewhere.It was a bit rough but it did serve the purpose well. I think a machinest would make a much nicer custom insert to suit each individual seat. I ran a single 1-1/4 SU carb with my 4 valve on a homemade inlet manifold. It really did get up and go.
Gene, another issue I had concern about was airleaks all the way down from the top of the head to the pan through worn lifters and guides. The filling of the old intake port areas completely was not an idea I had heard of but makes lots of sense. Back I the day Fahnestock made reference to using felt and springs top and bottom of the pushrods to seal the operating area of the pushrods.
Love your Speedster Seth. Thanks for sharing your project.
I have seen Warwicks idea used on a few engines over the years, seemed to work fine. I have a Riley 2 port on my Model A, with machined plugs in the valve openings.