tinman

You can get rocker stud girdles for $125 or so.
If you go to get one, make sure you twell whoever is selling it what heads you are using so you get the right girdle.
Hint, stock heads and everything Edelbrock makes are the same as far as the girdle goes. They also need to know what size rocker studs you are using, I'd sure recommend 7/16".

Duncan_GT

Yeah ive got the bigger 7/16. I dont think I'll get one since my cam isnt solid, just figured I'd ask since i was seeing both kind of girdles pop up over on the corral. Money i can spend elsewhere

wydopnthrtl

I can't comment on a 302 because I simply don't know about that engine.

I do have 1st hand knowledge of the mod engines though. You'd be amazed how much the crank & block flexes in worst case scenarios.
On a 5.4L we made a girdle and it didn't improve side -to- side movement at all. We we seeing 3-4mm (0.120"-0.160") of block deflection with or without.

Basicly if you want to strengthen the block from one main to the next you have to increase the metal thickness or somehow reduce the "box section" between them. And.. each of those mains are not stationary in of themselves. They are also moving because of other forces from other mains.

IMO people take the wrong approach when it comes to this issue. The FIRST thing that ought to be attended to is balancing. Get all those parts to within 0.01g of each other. When I balance I make them perfectly matched. And I mean every single part. Pistons, pins, retainers, rods, bolts, bearings. (rings and bearings never need modding in my experience)
Proper balancing will put less stress on the crank and block... which allows you to spin it a little higher and/or have a more powerful power stoke.

When I do a budget build the two things I don't skimp on are proper machning and balancing.

tinman

Another way of getting rid of a lot of block flexing is to fill it.
Not really practical for a street engine however.......

Duncan_GT

This block has had all of the machine work done to it, and everything is neutrally balanced.

What is filling? I read that somewhere else too but had no explanation.

tinman

Block fill is really nothing but a special grout that is used to fill the water jackets and make the block stiffer.
It should be done before any machine work is done.....

Duncan_GT

Yeah i wasnt going to fill it, just wanted to know what it was. Wouldnt that cause cooling issues?

tinman

Another way some people seem to think they can deal with block-flex is to use front and middle engine plates to mount the engine.........
That may work real good but I've never used them at all.
Also, IMO, comparing any of the new type 4.6 or 5.4 V-8 engines to the pushrod V-8's is beyound silly, they are 2 completely different things.....

Duncan_GT

I guess the ultimate question is at 500hp, with my block having all of the machine work done and my rotating assembly having an internal balance, do you think I'll have any issues with block integrity? Tinman, ill send you my engine specs again tor your simulation

tinman

Duncan, check your PM's