Mopar 350 small block

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paolo_mangusta
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Post by paolo_mangusta »

Just spoke to Real Steel, they didn't do this :(

What they did was a build up of a 360 block using chevy rods and pistons to get about 380 bhp (though this is what a 360 crate engine gets, so I can only assume it was a budget build with those cheap bow-tie parts)

So I'm back to square one unless I can find out what those pistons that Hot Rod used and I suspect Speed-o-motive aren't about to tell me ;)

Oh well
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Dave-R
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Post by Dave-R »

paolo_mangusta wrote:Just spoke to Real Steel, What they did was a build up of a 360 block using chevy rods and pistons
See. I do remember some things correctly! :roll:
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paolo_mangusta
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Post by paolo_mangusta »

Yes, but you don't get a prize because if you'd remembered it was a 360 block none of us would have got this excited :)

I can't find out what the pistons are anywhere, it looks like this has bitten the dust :(

Still, it was fun while it lasted...

Cheers

Paul
Anonymous

Post by Anonymous »

tried moparts, moparchat, etc. ?
Anonymous

Post by Anonymous »

OK, this is what I have come up with so far:
I did it, used Fed. Mog pistions lc371P, had to machine the skirt so as not to hit the counter weight on the crank.
So it can be done.

I'm pressing for a few more details but at least you know what pistons to use now.
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paolo_mangusta
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Post by paolo_mangusta »

Cheers :) I did have a look around but didn't see anyone else mentioning it. The guy I bought the duff engine off has said he'll give me some money back so I'll probably end up sorting out the other 360 block

When I looked at the 318 the pistons sat way down in the bore (I could fit 0.072 worth of feeler guages under a straight edge across the deck)

If you were happy to run super unleaded I reckon you could go for zero deck height with the 360 heads, which would only mean taking .060 to .070 off the top of the piston. I can't see that so little would weaken the piston significantly, although it would be under greater load.

I haven't worked out the CR exactly with this including the head gasket and everything (and given the variation in tolerances it would probably be wise to measure combustion chamber volumes rather than believe the book) but it should end up around the 10.5:1 of the 340s, given they sit .045 out of the block, which seems to roughly fit in with Steve's calcs

Although I think now that I'll likely just build the 360, part of me might just be curious enough to do this - I've got all the bits sitting about, it would mainly be the machining costs and the pistons (unless I just machine the stock ones I've got)

Hmmm :?
Anonymous

Post by Anonymous »

I think you get .045 with the stock pistons.

The 318 pistons sit .90 down the bore at TDC and in real life you may find they sit a little lower.

Mopar actually sell a 360 crank with 318 sized journals now...

Whether its a practical job or not I must admit a certain fascination with this one as well now. New life for old 318s and all that, after all there are millions of unwanted 'teens out there
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paolo_mangusta
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Post by paolo_mangusta »

The book I've got gives .060 down the bore for the 318, but I suppose they'll vary both from tolerance and as the cheapest way to vary CR over the years.

I've got a pic in the engine building book that shows the 360, 340, and 318 pistons side by side and the 340 is a lot higher than the others, and has valve pockets cut (which is the other thing you'd have to worry about with this)

Where did you see this crank?
Anonymous

Post by Anonymous »

that should be .090 not .90 as typed but I think you'd guessed that ;) I might well be wrong and it could be .060", and 318 experts still following this thread?

Not seen the cranks but have heard them mentioned, I haven't checked the MP catalogue but they are supposed to be available ready to go with the 2.5" main

I think the variation in compression was achieved with chamber size as IIRC all 318s have flat top pistons.
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