347 growing through the hood
 

My 302 was rubbing the rack and pinion and a few minor items, break line, etc.
bought a 347 crate motor from Prestige Motor sports. My problem is the oil pan. Martin built a pan for the stroker and added 5/8th" in the midsection. He also gave me a 5/8th " spacer for each motor mount bolt. I am still not high enough. Obviously need more height as it summed out.Lining up the motor mounts are also an issue. Anyone run into this problem. I dont think a few extra washers is where I want to go. 425 HP held down by 4 7/16th bolts running through 5/8th spacers is marginal at best.

Moving this post out of an LS oil pan thread into a new thread in Ford based. Should get good response here.

I'm curious as to why the bottom of the pan needs to be dropped 0.625".

A stock 302 motor has a 3.00" stroke; a 347 has a 3.40" stroke. So the total difference in stroke is 0.400". Half of that additional travel occurs at BDC and half at TDC; i.e., the actual crank arm is only 0.200" longer. So one would think a stroker pan 0.200" deeper would maintain the same clearance as the standard pan with a 3.00" stroke. I really can't see why you would need upwards of a half-inch extra when vertical clearance is so critical to the swap.

I think the rod bolts are typically closest to the pan, and the same bolts are often used for both displacements. Maybe some of the of the aftermarket rods have more meat in their structure and space the bolts wider apart? I don't know the answer, but it makes me curious.

Could be a lot of things sunshine guy, from more meat on the rod ends, to different counter weight design on the stroker . The problem with the LS7 vs other motors isn't particularly the stroke, as an aftermarket 4" Stroker rod clears better than stock Titanium LS7 rods. The rods are physically larger on the end, and use large bolts that just don't like to clear.

We'd have to know what crank/rod combo he has and maybe see photos vs a stock crank, its difficult to say.

It would be interesting to stick a thin layer of soft modeling clay in the clean bottom of the oil pan (at the closest clearance area), bolt the pan on and hand-rotate the engine. That would allow you to see where it is actually close and exactly how much clearance is really required.

To make the test easy/fast, you could bolt the pan on with no gasket and minimal torque. Then add the compressed gasket thickness to your observed clearance.

Eagle crank, Chevy rods. As we know. Martin's pan is modified to clear rack & pinion. Martin's pan needed additional clearance for rod bolts. So martin made a new pan with additional room. Total distance apron. 5/8th" don't what his standard distance was.he probably added 1/4." Don't know

That makes sense. I was thinking you meant the pan was clearance another 5/8" from where it is usually made for the 302 motor. Martin should know exactly how to do it; I think he owns one himself right now with a 347 in it.

That's very interesting...Chevy rods? Haven't heard of that, and I'm curious how it is done. The only thing that comes to my mind is a 400 small block Chevy rod that is 5.565" center to center, compared to the 347 stroker Ford rods which are most typically 5.4". It would take a custom piston that pushes the ring package up pretty tight to the top to extend the pin height by another .165" (and/or a smaller pin). I would think the standard, 5.7" small Chevy rods would be too long for a streetable ring package?

The Ford rod journal is 2.123 and the Chevy 2.10, so it would be pretty easy to open up the big end. I'm only guessing this is how it could be done, but it is an intriguing concept in any case. Regardless of how, I can see WHY; the decreased angularity would be nice for a higher rpm motor, or one with a power adder...if it doesn't push the rings up so high they get cooked.

There are generally 2 types of rods used in stroker kits, the "I-beam" style, and the "H-beam" style. The H-beam has more meat in the area of the rod bolt which puts the head of the bolt somewhat higher.

I tried to show this in these pics, but it's hard to get the right perspective. The big end bores are aligned, note the difference above the split. I-beam on top.

I think Martin had some bad experiences early on, so he probably errs on the side of caution.

Mike

Martin's early pan would only fit stock displacement 5.0's with stock Ford rod bolts. On my first build my father used ARP bolts and we hit the pan. A mallet solved the problem but encouraged Martin to make more room. As of my last build (5 years ago) he had added even more room due to the current trend rebuild Ford blocks as 331's over 306's.

-Jason