P&C Identification

[H2OSB]

Can anyone identify this pistons and cylinder brand?

[Marc]

I've never seen those markings. FWIW back in the day some NPR Type I pistons had "TS" cast into them; Jap pistons typically have a small divot right in the center of the crown, do these have that?

[H2OSB]

Thank you, Marc. Indeed they do...small divot exactly in the center of the flat top. Also on the crown a small arrow pointing to the flywheel, I assume, and the letters "STD".

I would only like to use the cylinders, if they're usable. The pistons aren't in the best condition. One still has a ring frozen in full compression (such that I cannot locate the ring gap).

Would the cylinders be safe to use, assuming they're sound? There are no fins broken off and no cracks I can see (I would have them checked more closely, professionally if it's safe top move forward.)

H2OSB

[H2OSB]

Anyone? bump

[Marc]

I'm unaware of any inherent weakness in Japanese cylinders, so if they check out OK I'd have no qualms about using them after honing provided the piston-to-cyl clearance isn't excessive.

I've only encountered ONE NPR jug (a big-bore 40HP 83mm) that had a pinhole in the casting - much better statistically than, say, Vicsa Brazilian. Can't speak to how "hard" they are since I've never used any in an engine expected to last a long time (and have only used cast-iron rings in them), the amount of ring-ridge worn into yours should help with judging that.

[raygreenwood]

The NPR pistons and cylinders were actually pretty good quality. Ray

[H2OSB]

Ray, is that what you think they are? Marc didn't seem sure. Honestly, though, it doesn't matter. If they check out, I'm going to use them with KB pistons

johnL

[H2OSB]

Marc, how can I identify them as T4 or T1? I got them as one of the items in a purchase of "T4 parts", and they had the pistons sitting inside of them. To me, it looked as though the guy was planning to build a 1911 and never got around to it (it all came from a shop just south of San Jose, CA that was closing it's doors after many years in business). The case, crank, and connecting rods I got in the deal are from a 1971 1.7L 914 engine, based upon the engine code (well, the block anyway...however, the crank and rods are still mounted inside the unsplit case.). The pistons measure out to 96mm.

I have a locally well known and respected engine shop who I was thinking about have check out the cylinders, however, they do NOT specialize in aircooled engines. Should I leave the inspection to someone who specializes in AC engines or should any reputable shop be able to determine their soundness? I must admit to woeful ignorance of AC engines, and I don't want to make a glaring mistake building my engine.

johnL

[Clatter]

Hi,

You are in San Jose?

I'm in Santa Cruz, and can help you measure your cylinders, if that works..

[H2OSB]

Nah I'm in Modesto. It was a nightmare to get those parts but I got a crazy good deal. If I turn them into most of a 1911cc T4 I'll really feel like I won. I really appreciate the offer of help on my cylinders, but it's a ways to go for me.

JohnL

[Marc]

Marc, how can I identify them as T4 or T1?...

Biggest commonly-available bore for Type I is 94mm, and 22mm is the largest-diameter wristpin (Type IV are 24mm as a rule) - can tell from the photo that the cyl is Type IV, too (the "notched" lower spigot is a distinguishing characteristic).

So long as you aren't having the cylinders bored, any auto machine shop should be fine. Checking them for diameter/taper wear and honing them is routine.

Are the pistons you plan to use hypereutectic or forged? The latter typically need over twice the piston-to-cylinder clearance.
I'll leave it to the Type IV gurus to suggest the ideal clearance. Will the usage be primarily street? Do you intend to run a thermostat?

[H2OSB]

Marc, thanks again! I plan to use Keith Black hypereutectics. I measured the pistons at 96mm but I never thought about the wrist pins. I never wanted anything more than a 1911cc (with THESE cylinders...kinda pinned for a 2056cc for a while, but I'm trying to build this engine on the cheap side) so no boring.

The car will be 75% street 25% autocross. I'm not brave enough for tracking and went out of my 1/4 mile phase last time I had a V8 powered vehicle.

johnL

[Marc]

I plan to use Keith Black hypereutectics. The car will be 75% street 25% autocross...

Hopefully you won't have more than ~.004" piston-to-cyl clearance then.
http://www.hughesengines.com/TechArticl ... istons.php