XXO/BVGC '38 Chevy Coupe Build

Started by 38flattie, July 21, 2010, 06:34:16 AM

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jimmy six

Geesh. . . . . . .  I get 2 runs on my GMC then its tear down time; that's why I unload it ready to qualify if I can.

Joe and I never got more than 2 in a row with the pan off in impounds everytime. We made 3 runs for five years straight but the head and pan were off after the first one, once with 11 bad valves.

Hey my son wanted a "hat" (and I didn't even have one)........................JD
First GMC 6 powered Fuel roadster over 200, with 2 red hats. Pit crew for Patrick Tone's Super Stock #49 Camaro

38flattie

#646


Doug, we expect we'll have to repair something, but like everyone else, we just hope it isn't catastrophic! Major congrats on the new records at WOS- you guys rock!!!! :cheers:

Gary, did I hear a 'return to the salt' mentioned? That would be great! :cheers:

Chris, that's probably not a bad way to look at it- it probably cuts down on the disappointment factor!

Bob, it's VERY good beer!

Tony, approximate piston speeds are:

3845fpm @ 5000 rpm
4239fpm @ 5500 rpm
4626fpm @ 6000 rpm

Regardless of the dyno results, the mag rev limiter will be set at 5000rpm to start with. I have no plans, this first year, of going past 5500rpm. The engine will be tore and and checked often, to see what kind of wear and damage we have, assuming we don't 'grenade' it.

Ok, please explain 'posting the cylinders'. You have to remember, I'm just a redneck that digs holes in the ground for a living- this fancy jargoned stuff isn't in my vocabulary!


Quote from: jimmy six on September 22, 2011, 10:29:57 PM
Geesh. . . . . . .  I get 2 runs on my GMC then its tear down time; that's why I unload it ready to qualify if I can.

Joe and I never got more than 2 in a row with the pan off in impounds everytime. We made 3 runs for five years straight but the head and pan were off after the first one, once with 11 bad valves.

Hey my son wanted a "hat" (and I didn't even have one)........................JD

Jimmy, you're a very generous dad! :cheers:
With sufficient thrust, pigs fly just fine. However, this is not necessarily a good idea. It is hard to be sure where they are going to land, and it could be dangerous sitting under them as they fly overhead. -- RFC 1925

You can't make a race horse out of a pig. But if you work hard enough at it you can make a mighty fast pig. - Bob Akin

http://www.flatcadracing.org/
http://youtu.be/89rVb497_4c

maguromic

Buddy, Posting was an old trick developed by, I believe Holman & Moody in the old NASCAR Days.  It was mainly used on the heads to help them, but was also used on the old blocks to keep the cylinders from going out of round.  To post the block you mill the block exactly on the bore center-line for 5/16" in diameter and spot face the cylinder wall and tap the hole for 3/8" x 16 threads.  You need to put more on the thrust side of the motor.  Then you use threaded rod and tighten them to about 5lbs, this is what gives the cylinder the extra support from flexing.  You need to do all this before finish boring to keep bore distortion down.   Most of your high boost compact car engines are having their blocks posted to keep the bore distortion down.

We are currently posting the GMC block and if you want I can send you some pictures on how it's done in the next few weeks. Tony
"If you haven't seen the future, you are not going fast enough"

SPARKY

Tony, picts inquiring minds need to SEE
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

"Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure or nothing."   Helen Keller

We are going to explore the racing N words NITROUS & NITRO!

GH

I got lost on the posting. Like sparky said, photos would help.

Rick Byrnes

Tony, I would love to see photos as well.
My Ford "Pinto" blocks are only a little more than 40 year old design and don't need as much help as those designed 70 and 80 years ago, it is still nice to see methods that work.
Please keep up your good work.
I enjoy
Rick

maguromic

#651
I will post them on my build diary in the next few weeks with a step by step.

Rick, 40 year old blocks, love them late model stuff myself.  :cheers:

This link has some good pictures of a Honda block being posted.  Its the same principle (they think its a new technology, and haven't looked at a 1960's  NASCAR block) and they even have kits for these guys to do it.  But being the crafty racers we are, its simple to build. (from a Honda forum) http://www.muller.net/sonny/crx/engine/posted.html  Tony
"If you haven't seen the future, you are not going fast enough"

Milwaukee Midget

Tony, thanks for the link,

While my casting is only 40 years old, the design is 60.  While I think I'm okay at .0315 over for a NA engine, if I ever rebuild an A-block with a turbo, this would be slick mod.

"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

Tman

Thanks for the link Tony, sent it to my partner, the engine guy. :cheers:

maguromic

If it can help one of you guys save a motor then its great.  I actually found out about the procedure when we were racing in the dark ages (before Ford SVO came out will all the trick stuff).  Our engine program was getting a lot of help from the Wood Brothers and Leonard Wood suggested that we post the heads at the ends to stabilize the combustion chamber area to avoid head gasket failure (mind you these were the days of building our own high port heads by milling and adding plates).  Ever since then I have done this to all of my vintage heads and blocks.  Posting the block is really helpful for our Bonneville GMC engine, where the compression ratio is closer to 17 to 1.  on our N/A engine. Tony
"If you haven't seen the future, you are not going fast enough"

38flattie

Tony, thanks for the info! The pics cleared things up for me.You always have so many cools tricks up your sleeve, I know that your build will be a major success!

Unfortunately, I'm passed the point where I can do this to the block without taking a big step backwards. It is something I'll look at for future engines,as it looks like it could be real beneficial.


With sufficient thrust, pigs fly just fine. However, this is not necessarily a good idea. It is hard to be sure where they are going to land, and it could be dangerous sitting under them as they fly overhead. -- RFC 1925

You can't make a race horse out of a pig. But if you work hard enough at it you can make a mighty fast pig. - Bob Akin

http://www.flatcadracing.org/
http://youtu.be/89rVb497_4c

Tman

I found a lot of info on posting but none on vintage steel blocks like we are using. Tony, what are you using for posts and sealer?

38flattie

#657
Dale finished match porting the top girdle, and prepping the block. Assembly is up next!
With sufficient thrust, pigs fly just fine. However, this is not necessarily a good idea. It is hard to be sure where they are going to land, and it could be dangerous sitting under them as they fly overhead. -- RFC 1925

You can't make a race horse out of a pig. But if you work hard enough at it you can make a mighty fast pig. - Bob Akin

http://www.flatcadracing.org/
http://youtu.be/89rVb497_4c

SPARKY

looks like that thing could be mad into  4 bolt if not a cross bolt
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

"Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure or nothing."   Helen Keller

We are going to explore the racing N words NITROUS & NITRO!

38flattie

#659
Haha! Sparky, that was a case of too many fingers in the pie!

The first thing Fowler suggested was cross bolting the mains.Somewhere along the way, many things and intentions were changed.

Can anyone tell me the 'popular' 4 speed being run behind the Jimmy engines?
With sufficient thrust, pigs fly just fine. However, this is not necessarily a good idea. It is hard to be sure where they are going to land, and it could be dangerous sitting under them as they fly overhead. -- RFC 1925

You can't make a race horse out of a pig. But if you work hard enough at it you can make a mighty fast pig. - Bob Akin

http://www.flatcadracing.org/
http://youtu.be/89rVb497_4c