Re: Let's build a drag race 8BA engine
 

The Highest compress you can get, on one of these engines, will be with FT pistons, with a CH or stroke set to get your piston within .042-.038 (possibly .036) of the head.

Even getting a dome head up to that clearance, will be a little less, because the dome shape, has more area than a flat. The transfer area shape, also will make a difference to the CR. The difference of how high the top rings is, also has a minor effect, as well as how thick the valve margin is.

Also, after posting my sim HP/TQ estimate, I asked around, on different sites, to find flow numbers on our engines. I found flow bench numbers, The guy, cut up a block, to mount on his bench and ported and installed 1.6" valves but, I only got the intake flow and I estimated the exhaust at a few cfm less, although I think the exhaust will flow more.

Anyway here are my revised numbers and what this flow looks like when added to the program.

Again, it's 239, 9.2 CR FT piston .038 head clearance, 1 carb on the stock cam and 3 x 165 cfm on the big cam.

In think the stock cam sim HP, is believable, take the 262 @ .050 cam, with .440 lift -.012 at what ever you want, it a pretty radical cam!

I would like a opinion, if possible, on the accuracy of peak rpm (5400) with that cam. The valve events are:

Lobe Lift .010--.020--.050--.200-- Max lift- .440
Duration 315.9-286.8- 262--189.5

Re: Let's build a drag race 8BA engine
 

The actual compression an engine sees is after the intake closes. It's called "dynamic CR" and is a good reason Long duration cams don't have allot of torque at low RPMs. The volume of the combustion chamber determinees the "Static CR". This includes the area over the valves. High lift cams need a place to put the valves when they open. Remember Horsepower needs air to make HP amd the combustion chamber is part of the intake port when it has to provide the AF to reach the piston. With all the Mathematical skills of our readers, determine the chamber volum you need to make 12:1 cR in a 276 engine, now a 350 ci.. This is the reason blowers make allot of HP

Re: Let's build a drag race 8BA engine
 

Mtt

Re: Let's build a drag race 8BA engine
 

Mercury cranks were Nodular Iron, or Forged Steel.

Re: Let's build a drag race 8BA engine
 

Yeah right.

Re: Let's build a drag race 8BA engine
 

14 to 1 CR on a Flathead ??? Dream on pal. Show us how you did it if it's true, which it ain't. Even if you welded the combustion chamber, the valves still have to have somewhere to go at cam lift. And if you welded all around the valves in the head, that motor wouldn' t breath work a s..., and it would'nt make enough power to fall off a curb.

Re: Let's build a drag race 8BA engine
 

There were never any forged flathead cranks.
The steel Mercury ones were shell molded

Re: Let's build a drag race 8BA engine
 

Ah, another expert has come aboard. Welcome.
It is common practice when a new poster comes on to introduce and tell a bit about yourself.

By the way, 14 to 1 or more has been quite possible since the early 50's.
The names, Smokey Yunick and Speedy Spiers and myself come to mind.

Re: Let's build a drag race 8BA engine
 

I used a mockup combustion chamber with a wedge piston and cylinder head made from wood the areary over the piston had an 8 deg angle and the piston a 7 degree angle. This allowed for exelent flow and a very hi compressio,
Several years later at Bivlle I saw an engine tare down for inspection with the same chamber. I had contacted Egge to mmake a set of pistons for me, but the cost was more than I could afford. But somebody thought it was a good idea.

Re: Let's build a drag race 8BA engine
 

Then tell us how ! Even that kind of cr on an OHV motor would be real hard to find high enough octane to run it without it detonating itself into little pieces. Show us all the proof. Oh, by the way, I have HotRod magazines going back to the late 1940s. If someone has achieved 14.2 on a Flathead, it'll be in there somewhere.

Re: Let's build a drag race 8BA engine
 

Smokey. That’s the guy that could not get the new Chevy Rat engine to make good power & live so Chevrolet had Smokey send the engine to Jr Johnson where a young Robert Yates’s was moonlighting after he got off from his day job at Holman & Moody. Robert made the big block scream with HP & survive. I will stop at that for now as the rest is history.
Cheers
Tony

Re: Let's build a drag race 8BA engine
 

These are race engines. We run alcohol.
I do have one customer that runs 118 race gas and it works fine.

I seriously doubt you will find any useful information on advanced engine development in Hot Rod Magazine.

As far as telling the World what goes into one of my engines other than what has already been talked about, that is not going to happen in this lifetime.
In the next lifetime, I will teach anyone all I know as long as they have an IQ equal to or higher than their age.

Re: Let's build a drag race 8BA engine
 

Yes, you are right. I was refering to Smokey and the Hudsons. I quit following NASCAR after that.

Re: Let's build a drag race 8BA engine
 

Getting 14:1 CR is difficult, but not impossible. Especially with a large displacement block. However getting any HP from it would be limited by the amount of air you could get into it. Alky is not a great fuel and you need twice as much by volume to equal any gas. Now with alittle Nitro, that's another story.. Oxygen is the key to horsepower. Yne more you have, the more power you get.

Re: Let's build a drag race 8BA engine
 

Interesting. Yes, I have some alky Stromberg jets that are huge!

Re: Let's build a drag race 8BA engine
 

Conversion from race gas to straight alcohol is good for at least 10% increase in hp. assuming optimum tune for each.

Re: Let's build a drag race 8BA engine
 

Pete,

How much of jump does that 10% represent in your typical race motors? Are we talking another 20-30 hp just from fuel & tune?

Re: Let's build a drag race 8BA engine
 

I don't know. I haven't poured any gas in one since the 50's except down the injectors to start.

Re: Let's build a drag race 8BA engine
 

They used to say that running straight alcohol let the engine run cooler. I don't know how much that would help in drag racing but I am sure it was a factor in stock car racing.

Re: Let's build a drag race 8BA engine
 

For exactly this reason, in the 90's someone sold alky-only racing heads that had no water outlets or jackets. They were a billet slab and the customer could choose their own compression ratio. I'll try to find the info on these.