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I need to ask my engine builder what he thinks but have any of you used a main girdle to increase the high rpm durability of the stock block or is it a waist of time?

Also any of you who purchased Buttmores new blocks, is the oiling system stock Cleveland? Do you still need to sleeve the lifter bores to restrict top end oiling?

I'm considering buying the aluminum block. I would suppose that it is still too soon for anyone to have raced it in the 8500rpm area?
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A mains girdle will likely have to be mated to a specific oil pan, you won't just be able to bolt up the standard Aviaid or Armando pan. If you are going that far maybe consoder a dry sump?

Forgive my ignorance but one would assume in any Al block the lifter bores would be sleeved?

8,500 rpm, what you gonna be doin' wi it?
Doug,

My thoughts. Making an engine survive at 8500 rpm requires a whole other level of build-quality more than 7500 rpm. If it were me, I would not only use a girdle, I would also dowel my four bolt main caps.

At that rpm the oem crank won't last long, and would need to be internally balanced. I would spend the $$ for a good internally balanced & lightened steel crank from Crower or Bryant, etc.

Everything needs to be blue printed, indexed & balanced. One of the steps in blue-printing is to re-drill each lifter bore "on center" so that camshaft timing is consistent for each cylinder. Lifter bores are way-off on production blocks, that's the main reason race engines have their lifter bores re-drilled & stuffed with bronze bushings. It never hurts to set the clearance between lifters & their bores tight on any engine, it just happens to be the "fix" needed for Clevelands and other motors with similar oil systems. By setting the clearances tight you insure that the oil delivered to the block by the oil pump is flowing to the main bearings, and not being lost to other "leaks" such as excessive clearance between the lifters and their bores. This also prevents excess oil from collecting in the lifter valley and dripping down on the crankshaft, where it is whipped into a foam that is not good for lubricating anything.

cowboy from hell
I'm considering what I need to do to build a competitive engine for vintage racing. The leaders were running down the big straits in that rpm catagory. The issue is that probably no matter what I build it won't have a very long life expectancy.

The Pantera actually has an advantage with the ZF in the gearing with 5th being a .7 od. That is presuming I can make it pull with power at that rpm.

Probably an engine that would survive to 7500 would be adequate. With the documented reputation of the stock 351c block developing cracks through the webbing at high rpm use, I am just considering my alternatives.

Probably the thing to do would be to use the Ford Motorsport 351w racing block. The prospect of titanium connecting rods and the like have me cautious at declaring any sort of serious intent.

My opinion frankly is that I am building a WINSTON CUP or NASCAR 351c to run with them and I don't know if I want to try. Been there done that but the drums seem to be calling again. I hate when that happens. Wink

When I built my engine I never seriously considered having to survive at those rpms. I'm probably safe buzzing to 7200 now.

I'm just here picking brains for crumbs.

I need to consider at this point if I can compete with 650hp 289's, etc, or even want to.

I just never heard anyone discuss the useage of a main girdle on a C before.

The best engines come apart regularly at the big rpms. See. I'm answering my own questions already. Wink
Do the vintage regs rerstrict what goes into the engine?

My 620HP 393C was built by Klein and is supposedly designed to rev safely to 7,850 rpm.

It's not in the car yet, we'll see how long it actually lasts, but then again I'll likely rev limit it 7,500 rpm.
quote:
Originally posted by Joules5:
Do the vintage regs rerstrict what goes into the engine?

My 620HP 393C was built by Klein and is supposedly designed to rev safely to 7,850 rpm.

It's not in the car yet, we'll see how long it actually lasts, but then again I'll likely rev limit it 7,500 rpm.


Sure there are restrictions but the way the second tear engine builders are complaining there are almost no restrictions. The big deal seems to be whether or not you can run roller rocker arms.

Jules the question is not if an engine will rev to 8500 rpm, but can it run all day long at that rate.

I would take a guess here and say that very very few can and most guys don't want to really find out.

At $4000 a set for titanium connecting rods and $400 each for titanium valves these engines ring up parts like a drunken sailor blowing a wad.

It isn't just the parts that cost . It is time on the dyno to maximize everything virtually weekly. This is serious stuff that looks like it may be one notch away from wrestling with the Ford and Chevy racing programs.

OK. Everybody explain to me again why I don't want to do this please. Is this all what they call a self-reinforcing delusion?
Joules is corect. All day? What are you planning??? NASCAR pushrod engines that run at, for instance- Martinsville short track, turn 9200-up rpms for 250-500 miles. They cost 'over $80,000' each to people like Jack Roush who buy parts by the truckload and test 24/7 to utter failure on dynos. Most internal parts are thrown away or sold to street guys on E-Bay after a single use- including the crank, rods and Ti-valves. FWIW, there is not one cheap factory bolt, nut, casting or forging in these engines.
On a more reasonable note, as long as you're not trying to run Bonneville or a 92-mile-long Silver State open- road race in 3rd gear, and you use other than a production 351-C or 351-W block, you won't need a main girdle. You may need a VALLEY girdle that ties the two cylinder banks together to keep from owning two four-cylinder blocks, although splitting open like a walnut is usually confined to over-revved 5-liter blocks- both factory and aftermarket. The weak spot in production 351C blocks is above the main bearing bosses where the cylinder water jackets end; main girdles, aftermarket 4-bolt mains and aftermarket con-rods will all still be torqued to specs when the whole lower end of the block blows clear thru the oil pan, dry-sump or not. This happened at LeMans in 1972 on the Bud Moore stock-block engines used in the semi- factory GR-4s, incidently. Most hi-rpm V-8 engines built nowadays are for drag racing and you can get away with lots there that will be fatal in a long-distance high rpm endurance engine. Good luck, all you lottery winners....
Never heard of a block split in half from the top but I am not doubting you BW.

As far as what am I intending to do with it? Let's just say that the target, better word model, is Kurt Voght's 65 Shelby GT350 R. If you know it then it is self explanitory.

I would say that it was a $50,000 engine not $80,000 but who's counting amongst friends right? Big Grin

The reality is a harsh one of sorts and it is that only another engine builder would want to attempt to compete with that or as you say a major team like Rousch.

I'm neither but it doesn't cost anything to "consider" it. Wink

Apparently all along there has been an issue with race dependabilaty of the Pantera race engines. What was the major issue that the Pantera GT4 race teams had with the dependabilaty of the 351c? Is it just generally speaking over reving the engine?

The 351c ran quite a while in NASCAR. Was the "Nascar Australian" block the only fix?

Don't mind me. I'm just delusional. It will go away soon. Just remember to help talk me out of this.
quote:
Originally posted by DJEZC:
Would Dart's Sportsman or Iron Eagle blocks disqualify you for Vintage events?

They seem like an ideal solution. I know the Iron Eagle is rated to something like 2000hp and 9000rpm?


I think you are permitted to substitute what is the closet equivelent to what the "race" setup would have been "then".

Part of the 'bitching' is about non stock block engines.

I would want to stay with a Ckeveland block if possible.

Some of the NASCAR blocks tested a little thin on the thrust walls.

I kinda like the idea of Buttmores aluminum block. Joulse is right. The lifters would have to be already sleeved.

I think I could be happy with a 7500 to 7800 short block.

Funny thing though. When you get on the track, 7500 doesn't sound very fast. Smiler
Sportscar Vinatge Racing Rules are as follows:

Detomaso 1967-1988351 bore and stroke 4.0x 3.5 heads and block cast iron. Correct displacement is required. Engines must be of the correct type, size & design originally fitted. Over bore.047,

Modern aftermarket blocks and heads are prohibited unless they are indential to the originals.

Under the Detomaso Pantera Homologation the Group 4 cars and all their alterations are legal for example webers, CV joints, rol cage,plexiglass, Upgraded brakes, headers, high dome pistons, flairs, dual disc clutch and aluminum flywheel.

Why any other block is ban is because a Pantera never came with and High Perf block or any other engine .

Ron
A couple secondary thoughts;

1. I know of one 1986 Pantera that came factory with a 351W with C heads.
2. You could stablize the block by filling the cooling on the bottom of the block with 6000psi grout about 2/3 of the way up ..the bottom of the block dosent generate heat. This stablizes the block. I ran 4 428 Cj this way ..due to thin cylinder walls and it worked for me.
3. Pick any one of the FORD SVO block and they are legal.

Ron
In he past I was going to prepare a VSRA Pantera. With the advise from many and looking at the History of Racing Panteras I noticed a History of DNF's DID NOT FINISH ... as in life a lot can be said for history.

So with that said I started looking for a Mustang and came across a nice 66 Coupe 3rd in point standings for a very resonable cost.

So I consulted with a few racers and thye all said the same thing. " you answered your own question....an SVO block is a FORD block and a DART block is a aftermarket block.

Ron
PD,
Buttmoores blocks "look" good but have not been tried and trued!

http://www.network54.com/Forum/119419/message/119794227...+NASCAR+Block+Photos

Something from the past to consider for Vintage Racing might be the 351C NASCAR blocks if you can find one, I myself am using a 4 boltmain std bore block set up for ORR, I like to keep it simple and use the factory proven parts.

Good luck, Mark
Last edited by sickcat
I believe I may have girdles on my stroker on my Group 4. Are these the guides that come up through the valve covers (see my Group 4 photo link below)? I was told the set up on my car from Kuntz & Craft build will stand up to very high RPM due to these, so I figure these are the girdles? I have a 6,500 rev limiter, but I never go there anyway to avoid the local gumeshoes.

http://rides.webshots.com/photo/2379725920043857827WPXZvL
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