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Discussion Starter #1
Okay, say you have an engine that is going to be around 400hp. It is some mid-70's 302 block. Do you, or do you not, need a stud girdle to support the main bearing caps? Opinions?

Thanks in advance,
Ted FB
 

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Had it both ways over the years....no difference...

Caveat is that I've always used early stuff...some folks feel the castings were thicker/better...I don't know..

If you were making 400hp from a 302 (I made that much from a 289 in early efforts in the race car), I wouldn't worry about it. If you're stroking the engine, your changing rod angularity and angular loading on the main caps....I might be more prone to using one in that case...

If you're building with adding more HP in the future in mind, definitely use one.

Make sure, if you do, that all the main cap bolt registers, after line honing, are in the same plane so even loading of the caps occurs.
 

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Discussion Starter #5
This is a bit of an after thought because the engine place that did my long block said they did not think I needed one. However, I have since heard of at least one person that had a problem with an engine from this place (engine place to remain nameless unless my engine blows up too!) I had not thought about the bearing caps needing to line up nicely. I could do more damage than good putting one on if they don't. Good point! I don't think I will put one on since I would need to take the block to a shop somewhere to have it checked properly. I don't plan to try to get more out of it later. This is mainly a fun to drive Friday type of car. Or will be if I ever get it on the road!

Thanks again,
TedFB
 

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Ted,
A lot of folks (even engine shops) don't think of such things but the combination of being a machinist who works on highly stressed equipment and being a racer for more time than I care to mention *G* kinda gives me a more anal perspective...

Easy way to check is to pull the caps and measure (with an outside micrometer) the distance from the cap/block mating surface to the spot face where the bolt head (or nut) resides. They should all be equal...

As the machine work to the block puts the main registers in the same plane, if these distances are equal, then the girdle will sit completely flat on the caps (assuming it is flat...I had the ones I built in the past blanchard ground). If some of the caps are off, measuring to find the shortest one and then machining all the rest to the same dimension will do the trick...Pretty easy to do with a simple clamp jig in a Bridgeport and a 1" or 1 1/8" end mill.

For casual use, I don't feel a girdle is necessary...but for sustained high loading, like in endurance racing, or shock loading, like in drag racing, I think it is worth of consideration for anyone who's using a 2-bolt main stock block.

I had even designed an integrated girdle which attached to the main caps and pan rail, ala the FE 427 cross bolt blocks, but never brought that program to fruition. I was working on a 2+ hp/ci 289 based engine for SuperGas at the time....

This stuff sure is addictive, eh?? *G*
 

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Tell us more about the 2hp/cu in 289.Did it hit the magic number?What kind of heads?Power adders?
 

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Tell us more about the 2hp/cu in 289.

The project derailed in '84 when my father died and I started my business shortly thereafter, which took most of my capital...

I was working in concert with a chassis builder who had his 289 in the mid 10's in a very light '65 coupe...and one of my old racing buddies (the one who gave me the Cobra manifold) who had be racing Fords since the flathead days.

Let's just say we built stud girdles and main cap girdles and made oiling system and head changes long before they were popular with Ford enthusiasts...The 351W heads I often mention here, which I ran on the race car, were an integral part of the program and there were some failed experiments with changing valvetrain geometry (ala TFS) and exhaust port shape and geometry..

Some of the carb spacer work I talk about here (I'm not telling all *G*) was an outgrowth of those years. Even my cobbled-together-appearing 3310 has much more to it than meets the eye, long before one could order such stuff from Holley or BG (Demon).

As with many things in life, I enjoy these challenges and am not interested in profiting from them. That's why I share as much as I do on the VMF. I do want to keep a few things to myself though, in case the budget allows me to start racing again..*G*

When I try to help VMF'ers struggling with the same things I struggled with 20+ years ago, I often am amazed that I did as much as I did at such a young age. Must have been the energy of youth...*G*

Oh, I never did experiment with N2O or supercharging, although some of my colleages did...my designs were very simple, with modest camshafts, lots of compression and balanced drivetrain-chassis combinations, a philosophy which I try to espouse here, with varied success.

I never reached the magic number (in this case 600hp) but I did have a number of memorable years walking the path...
 
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