Scuncio Chevelle ex-L78 - Page 9

**luzl78** · #81 02-22-2021, 08:51 PM

Use remflex gaskets.

**big gear head** · #82 02-22-2021, 09:37 PM

Was this supposed to be a L78 engine?

TomN · #83 02-23-2021, 05:29 PM

big gear head - It was advertised as being just a big block engine.

Engine Pad I.D.'s it as a 1969 Camaro L/78 engine block. Should have come with an automatic trans, and is date code correct for this car build. It is a 4-bolt block and it does have the square port heads, with aluminum intake

But no, it was never said that it was an L/78 engine

**big gear head** · #84 02-23-2021, 05:30 PM

OK. The cast crank and cast pistons are not L78 parts, so it made me wonder if it was supposed to be one. Watch your RPMs with those cast pistons.

TomN · #85 02-24-2021, 05:38 PM

Thanks .. big gear head. I knew those weren't L/78 parts but that brings up a question that has been running through my mind ..... just how many rpm's can those parts take. I'm not going to be making enough HP to worry about, but what about rpm's. Square port heads and L/78 cams like a little more rpm's than an oval port.
I may put a different engine back in the car - it's a standard bore 2-bolt block with a steel crank, forged L/78 pistons and square port heads -we'll see.

**big gear head** · #86 02-24-2021, 05:57 PM

Most people consider 5500 RPMs the safe limit for cast pistons. Stroke, rod length, compression ratio and other things will have an effect on this.

TomN · #87 02-24-2021, 06:23 PM

Well in my case it is stock 3.76 stroke, stock rods at 6.135, and around 9.5 compression.
So we will have to see....

TomN · #88 03-07-2021, 10:05 PM

I haven't done anything with the engine yet. Still weighting my options. I do have a std. - std. steel factory crank + a set of rods with the 7/16 ARP bolts.
Also have another standard bore 2-bolt main 396 block. So I'm ..... thinking

**big gear head** · #89 03-08-2021, 02:07 AM

Stick that crank and rods in your 4 bolt block with a good set of forged pistons and let it spin to 7000 RPMs. I used a 6223 crank and a set of polished and shot peened LS6 rods with ARP bolts and TRW pistons and shifted it at 7000 for several years. I've got better rods and lighter pistons in it now and going to 7300. Just be sure that the valve train is up to it. Dropped valves set off a huge bomb.

TomN · #90 03-09-2021, 03:27 PM

luzl78 - thanks for the tip, but I guess I don't know what remflex gaskets are.

big gear head - thanks, that is what I think I'm going to do, and get the whole thing balanced.

I'm also thinking about using the cast nodular iron crank along with the factory rods with upgraded bolts in the standard bore 2-bolt main 396 block. It already has factory forged 396/375 pistons. Will the crank take 6500 rpm's

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TomN (03-09-2021)

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TomN (03-09-2021)

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