Relieved stroker motor with Ford aluminum heads
 

I am in the process of starting a 40 ford Pickup rebuild project and am considering building a stoker motor from a factory relieved block. I have read a little of the comments on here about the pros and cons of them . My plan is to bore the block to 3-5/16 and use aa 4-1/4" stroke crank. it will be ported, and have the usual things added to it but I do have to use the original type carb, distributer, and a single exhaust. I am aware of the relieved block having a slightly lower compression ratio, my question is, would the Canadian ford built heads help? I can't find much information on them . I don't want to use aftermarket heads for this project since I want it to appear factory. Is there any advantages of using the relieved block? I was hopping it would breath better? I am looking for someone with experience with them both ways I guess. Thanks
Ron

Re: Relieved stroker motor with Ford aluminum heads
 

There really won't be any advantage to a relieved block for what you're doing (given the single carb setup) - but if you have a good block, I'd surely not be afraid to use it. Starting with a known good block will make your life a lot easier.

Given that you're only going to run one carb, you might want to consider one of the 'Big 97's' - it will at least look the part. You may have to be selective in which original style intake you use - such that you can bore the intake (at the top) for the larger carb. If you don't put more carb on it and only run a single stock Holley 94 type carb, you're not going to be doing much good with all the cubic inches you'll have - as you won't be able to feed them. So think about your plans and the carb-manifold before you head down the path.

If I was going to stick with a single carb (even a Big 97 at 250 CFM), I would lower my cubic inches and probably build an engine with a 4" Merc crank and a more conservative overbore - like .060. If you don't have the carbs for the cubes . . . they don't make a lot of sense.

Re: Relieved stroker motor with Ford aluminum heads
 

We have done work with the carbs before and know some of the tricks you are hinting at, I do have a good unrelieved block that we could also use. The past motors were 4-1/8" strokers, this would be the first 4-1/4" motor we have played with.

Re: Relieved stroker motor with Ford aluminum heads
 

Does anyone have experience or information on the Canadian heads?

Re: Relieved stroker motor with Ford aluminum heads
 

I have Canadian heads on my sedan. They have less pocket in the area between the valves and the bore. That's where the higher compression comes from.

My engine is a 3-3/8" by 4". Not really a killer motor though, I think because the old unknown cam isn't quite as radical as it could be.

Re: Relieved stroker motor with Ford aluminum heads
 

Re: Relieved stroker motor with Ford aluminum heads
 

You are starting off with 2 1/2 strikes against you with an early block.
Ford found they didn't work in stock applications and moved the valves. They definitely don't last very long in a race engine.
Cracks between the valve seat and cylinder is the problem in case you hadn't heard.
The relief was not the problem, the closer distance of the valves to the cylinder was the culprit.
With the cubic inches you will have, compression will be no problem. You can run any heads and still have too much for gas.

In ANY performance engine, a relief helps. It has to do with moving the charge path closer to the cylinder. Flat top pistons help to shorten the path also.

Re: Relieved stroker motor with Ford aluminum heads
 

I agree with B&S and Peter here A 284 ci engine with a 2GC carb on a bored Merc intake will feed the engine quite qwkk and a set of EAB heads will put the CR close to 9:1. Get a dist. from Charley NY and your troubles are over. These heads will work on an early block, just plug the right holes. But a late block is worth the effort.
Gramps

Re: Relieved stroker motor with Ford aluminum heads
 

I have to say, what is the point of all those cubic inches when you're also trying to run a single small 2 barrel carb and single exhaust? Seems like one big waste of cubic inches and cost . . . only to be choked off by a small original looking carb. Not trying to be harsh, just trying to be realistic. :cool:

Re: Relieved stroker motor with Ford aluminum heads
 

Claimer?
Class cheater?
Class rules?

Re: Relieved stroker motor with Ford aluminum heads
 

I gotta believe, that these days, this is not an issue in the flathead classes (If they still exist).

If I had to guess, I'd say this guy wants to beat up on some second-rate SBC powered street rods with a "stock" flathead.:D

Re: Relieved stroker motor with Ford aluminum heads
 

Flathead vintage circle track is alive and well in many parts of the country.
I am not sure what the covid thing has done to it though.

Re: Relieved stroker motor with Ford aluminum heads
 

Pete, I used to vintage race a lot here in the Midwest, and the major concern was always car count, not class rules, Maybe things are better in your neck of the woods.

Re: Relieved stroker motor with Ford aluminum heads
 

Although this goes back awhile at Danbury raceway the ruls changed allot for the car from pure stock to 2400LB modifieds. But the engine rules remained the same 258ci any flat tappet cam, stock intake.. Lap times wemt from 20 sec to 16 in 10 yearss.

Re: Relieved stroker motor with Ford aluminum heads
 

It’s not a circle track race, it’s a form of a old time drag race . I understand the issue with the exhaust and carb, however in this event, it’s a very competitive group of guys trying to go as fast as possible and still maintain some limitations, at least visual limitations lol. Clear down to tire size and type. What’s inside the motor is left to speculation. Lol I realize my questions might not make sense, and I also realize the problem with a 59ab verses a 8BA, however I am stuck with the 59AB and truthfully we dont run long enough to get the cracks common to them. My question was really just about weather a relieved block would be worth messing with and if I did would the Canadian heads be a benefit or not. I appreciate all the information though. Some of it was helpful. Thanks

Re: Relieved stroker motor with Ford aluminum heads
 

We usually have at least 25 cars. We have always had a few that think they have to cheat even if they are not winners. I never could figure that out when no money is at stake.

Re: Relieved stroker motor with Ford aluminum heads
 

Listening to your rules I would not use relieved block & whatever heads give most compression cast or aluminum.

Re: Relieved stroker motor with Ford aluminum heads
 

We had those guys, too. Towards the end it got to be a real problem. Big block Chevy's, IFS, and such started showing up on a regular basis. Those guys had no idea what it was all about.

Re: Relieved stroker motor with Ford aluminum heads
 

Re: Relieved stroker motor with Ford aluminum heads
 

This is odd, as just going to a 2G on the '51 Merc in my '51 seemed to make a significant improvement.

When you say "There was no noticeable performance difference.", can you clarify from what? Did you run duals or a tri-carb set-up on it before?