Weiand 8.75 Heads
 

I have a set of Weiand heads 8.75 stamped at water neck. They are 59a style so I presume the CR was calculated based on a 239. What are your opinions on installing them on a 8ba standard bore with 4” crank? I have read that Flatheads don’t work great past around 9:1
If a guy were to build a 276 would you run these heads?

Re: Weiand 8.75 Heads
 

Some times when the CR gets to high it is call hopping them down. Here is an old Ed Winfield story. A kid I knew growing up had a 1/4 midget back in the late 50's. His dad knew Ed Winfield very well. I forgot what engine he had. Some sort of flathead that met size spec. Well Winfield ported and relieved it and did a cam upgrade. This kid was always winning. He got older and interested in other things so the 1/4 midget was sold. New owners kid was then a consistent winner. They tore it down and checked CR and was surprised how low it was. So the head was milled to get CR up and that ruined the breathing characteristics. Maybe call it a Tune Down. It quit winning.

Re: Weiand 8.75 Heads
 

Interesting story. It makes you wonder how many sets of aluminum heads have been installed that have improved the appearance of the engine but diminished the performance. I have a set of EAB heads, maybe they are a better choice.

Re: Weiand 8.75 Heads
 

That sounds like Kong Jackson’s kid with the winning quarter midget, i raced quarter midgets against that kid in 1956-57.

Re: Weiand 8.75 Heads
 

What ever the stamped CR is: You might want to cc the chamber before you worry about the actual compression. Now how much cam lift will clear the head. At least you;ll have something to work with.

Re: Weiand 8.75 Heads
 

To use them on an 8ba block, you need to plug a small water hole on each deck.
It will be obvious when you lay an early big bore head gasket down.

Flatheads work great at 15 to 1, but 8 to 1 is a good street number.

Those heads will work fine on a 276 as long as you check for valve and piston clearance, flatness and make sure the fire ring does not hang over anywhere.

Also check the plugs you will run to see that there are no sharp thread edges exposed in the chamber. Adjust plug depth with solid copper washers intended for that, if need be. You should be using solid copper washers anyway.

Re: Weiand 8.75 Heads
 

15 to 1 ? What are the specs on that flathead

Re: Weiand 8.75 Heads
 

Thank you Ron and Pete, I was hoping that you guys would comment, I really appreciate the advice you offer on this forum. I’m going to try them first on a 255 with a Schneider s-100 and edelbrock with four 81s. The block is relieved so that would help to diminish CR slightly. I will cc them, clay, adjust plug depth as suggested. Cheers.

Re: Weiand 8.75 Heads
 

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Re: Weiand 8.75 Heads
 

Out of breath at 46-4800 RPM? That's a lot of cubes to feed through those restrictive intake ports! Or are the ports realigned, relocated, welded, epoxied, etc.?

Re: Weiand 8.75 Heads
 

good idea on a unknown set of heads, to understand if they have been previously milled. Over milled vintage heads are not uncommon. Guess you could stack gaskets as a "fix" :rolleyes:

Re: Weiand 8.75 Heads
 

No welding etc on intakes.
Hp peak at 6500. 328 on straight alcohol.

Re: Weiand 8.75 Heads
 

Impressive! I stand corrected. Do you have any videos/film with sound? Any build data you care to share? Thanks!

Re: Weiand 8.75 Heads
 

Modeleh here is a chart that might be helpful after you cc the head.

https://web.archive.org/web/20160318.../compratio.htm

John

Re: Weiand 8.75 Heads
 

Thanks John that’s good information I haven’t seen posted before.

Re: Weiand 8.75 Heads
 

charts are good, but can be misleading. The combustion chamber is much larger than just the head volume, like the head gasket, piston to head clearance, valve eye brows and a relief if you have one.. I add 15cc's to the head volume just for kicks. At least it's closer to reality.

Re: Weiand 8.75 Heads
 

I bought a burette I don't use anymore. I have found that aluminum foil balls held in place by a bit of grease and bolt the heads on to be a much better indication of what's really going on. The last set of Edmunds 8BA heads turned out needing to be "angle-milled" from .040 on one end to .000 the other to bring the combustion chambers into spec. A couple of test fittings made the problem become obvious (the block had been decked incorrectly). This engine has been running strong for the last two years and several thousand miles..

Re: Weiand 8.75 Heads
 

Both good points.
I like the idea of the foil balls. What is the recommended minimum clearance from piston crown to head and from open valve to head?

Re: Weiand 8.75 Heads
 

.045"-.050" for piston crown to head, and .060 over the valves (I don't run wild cams and have never even been close over the valves). For a street engine, I like to be on the high side. In addition to increasing the compression ratio, it promotes better combustion of the fuel/air mixture because it optimizes the "squish" area above the piston. For more detail, there are many threads, both on here and on the H.A.M.B. An increase in compression is always helpful in increasing performance AND fuel economy. Given today's fuels, we shouldn't be constrained to the stock Ford compression ratios, that were 7.2:1 at their best. May be the restoration guys would like to, but if you actually drive your cars, It's the way to go.

Re: Weiand 8.75 Heads
 

If you look at the Model A forum, most run "touring" engines. Restoration doesn't mean you can't shave a head, if it's the right head and it works.

Trial and error! You'll figure it out.




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