Chuck’s engine build thread!

[Craig Nedrow]

104* may have been very good with the stuff you have in the engine. Yes there will be more overlap, worse gas mileage, more emmisions....my kinda' engine. I have really enjoyed watching your build, being a born motorhead and machinist, engines and mechanical, I love that ---T.

 

[ChuckN]

104* may have been very good with the stuff you have in the engine. Yes there will be more overlap, worse gas mileage, more emmisions....my kinda' engine. I have really enjoyed watching your build, being a born motorhead and machinist, engines and mechanical, I love that ---T.

Thanks for chiming in bud!

 

[ChuckN]

Cam is dialed, checked out fine. Got the rings on the rest of the pistons this morning, put them all in and started plastigaging the rod journals. Looks a little tight so far at halfway between .0015 and .0020 (17 or 18?) but my machine shop says that the bare minimum is .0015 is fine so I’m gonna leave it. Seems silly to redo everything for .0002 of an inch, and plastigage reads a little fatter anyway due to the movement with removal. Taking a break for a little bit.

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[82SquareBurb]

Seems to be in spec, I would send it. 10w30 should be fine since its on the tight side. Good work Chad!

 

[ChuckN]

Seems to be in spec, I would send it. 10w30 should be fine since its on the tight side. Good work Chad!

Thanks bud!

 

[ChuckN]

Seems to be in spec, I would send it. 10w30 should be fine since its on the tight side. Good work Chad!

How often do you trust plastigage? It seems to me that it could not be any tighter than that- but one gentleman recommended pulling them out and checking with a Verneer caliper since they’re all so close. Thoughts?

 

[legopnuematic]

FWIW, here are the clearance specs from the 79' overhaul manual.

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I personally wouldn't have any problem with running them at .0017 or so. As long as the roundness of the journal and rod end are good, and when assembled isn't uber tight rotationally, choose an appropriate oil viscosity and send it.

 

[ChuckN]

FWIW, here are the clearance specs from the 79' overhaul manual.

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I personally wouldn't have any problem with running them at .0017 or so. As long as the roundness of the journal and rod end are good, and when assembled isn't uber tight rotationally, choose an appropriate oil viscosity and send it.

Thanks for that. Sometimes I get lost in the deluge of information and various advice that for a street strip motor that 20 thousandths or more is best, or that plastigage isn’t viable at all.

The old “too much information “ thing and it’s exhausting at times.

 

[HotRodPC]

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The honing has begun…

Glad to see a torque plate used. And it should be being that SBC is so very common I'd think every machine shop has one, but even lazy guys don't use it when they have it. For those who don't know the purpose of a torque plate.... So when you torque your heads down, you're pulling those threads in the block. It's enough it can actually egg shape your cylinders, now they're not 100% true and round. By using a torque plate to mimic a head being torqued down, the cylinder is honed to be trued as if a head is torqued to the block. They even use the same length amount of threads on the torque plate that you'd be using to bolt the heads on. Who would think a head would do that to the block cylinders? That's why machine work being done proper is so important. Anyone can assemble an engine, but it's only going to be as good and thorough as your machine work.

 

[82SquareBurb]

How often do you trust plastigage? It seems to me that it could not be any tighter than that- but one gentleman recommended pulling them out and checking with a Verneer caliper since they’re all so close. Thoughts?

I used it years ago when I was a machinist, I have always used mics / calipers to check bearing clearances, but I did use plastiguage on a few builds just as a "check" then miced one journal and it was very close. Close enough I would trust it anyway.

I mic stuff just out of habit and for peace of mind, and mostly because I was building stuff for paying customers in a previous life, and it HAD to be right. I don't think it's mandatory to be honest.

 

[ChuckN]

I used it years ago when I was a machinist, I have always used mics / calipers to check bearing clearances, but I did use plastiguage on a few builds just as a "check" then miced one journal and it was very close. Close enough I would trust it anyway.

I mic stuff just out of habit and for peace of mind, and mostly because I was building stuff for paying customers in a previous life, and it HAD to be right. I don't think it's mandatory to be honest.

I hear ya. At this point, basic calipers is all I have, and I don’t trust the calipers I have, they’re inconsistent. Which means I basically everything out and have my machinist look it over because at the consumer level of available tools, I’m not sure it’s worth it. Or I go with it as is.

 

[TotalyHucked]

My dad, several of his friends, my friends and me have all used plastigage over the years and it's always been fine. I used to see it on Engine Power on Power Block, you wouldn't think those guys would use it if it weren't pretty accurate. But here all of a sudden, I've been seeing the same thing all over the internet "don't use plastigage, it's not accurate. You're a hack if you don't have bore gauges/mics/etc". Like, what? Where did y'all come from and where did you get that info??

 

[ChuckN]

My dad, several of his friends, my friends and me have all used plastigage over the years and it's always been fine. I used to see it on Engine Power on Power Block, you wouldn't think those guys would use it if it weren't pretty accurate. But here all of a sudden, I've been seeing the same thing all over the internet "don't use plastigage, it's not accurate. You're a hack if you don't have bore gauges/mics/etc". Like, what? Where did y'all come from and where did you get that info??

For sure. I mean, in my high school back in the day, we were all told that plastigage was perfectly fine and acceptable, and part of a normal routine use for engine building.

 

[DoubleDingo]

My dad, several of his friends, my friends and me have all used plastigage over the years and it's always been fine. I used to see it on Engine Power on Power Block, you wouldn't think those guys would use it if it weren't pretty accurate. But here all of a sudden, I've been seeing the same thing all over the internet "don't use plastigage, it's not accurate. You're a hack if you don't have bore gauges/mics/etc". Like, what? Where did y'all come from and where did you get that info??

I wouldn't listen to them. Millions of solid engines were built with the use of plastigage. Heck, the 350 I rebuilt with Pop back in 1985, we used plastigage. Reused the rods, pistons, crank, cam, lifters; rehoned the cylinder bores and lifter bores, fresh rod and main bearings, fresh rings, and that engine after being ran hard from 1986 to 1994, roughly 194,000 of mostly highway miles, never redeveloped a ridge at the top of the cylinders. It was a great engine, never used or burned oil, and if I hadn't sold my 56, I'd still have that engine today.

 

[xm20k]

It's a good enough check to see nothing is too far off. Of the dozens if not a hundred plus rebuilds over the years I've used it as a final check on every one and it caught a miss machined crank and probably saved several thousands worth of damage.