Tech / General EngineWhy is my car making that sound? My car won't start! Combination questions? Don't see a board for your problem or have other technical or engine specific questions? Post them here!
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I have a 1988 camaro that i put a 327 sbc in. It was my dads, and it was sitting in his garage for about 2 years. I've put 3000 miles or so on her in 5 months, but i have come to the conclusion that the piston rings aren't seating properly, and i am getting significant blow-by.
The block is a 3970010, 2 bolt, and the internals are all forged, gm steel crank, gm rods, and speedpro forged dome top pistons.
if i get new piston rings, can i reused all the bearings/ main bolts, rod bolts, etc?
Also, would i need to hone the cylinders to get a fresh surface for the new rings?
Also, if i wanted to switch for arp main studs, would i need to get the mains line honed and get new bearings???
would this rotating assembly be suitable for 7200 rpm??? like all the time??? its my DD, but put the motor to work on the on-ramps quite often. I just can't get over that sound.
I have been taking to to 7000 a lot, but can it handle it without risk of breaking?
-josh
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__________________ 1988 Camaro RS. Color - Faded blue. 19 years old, daily driver to work and school. Runs like a champ... 80% of the time.
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There's no way of saying without knowing what machining/balancing was done to it and seeing what the cylinders/rings look like now and doing some measuring. If you just change the rings, it's probably not going to help.
If you go from main bolts to studs, the block should be line honed. Studs load the block and main caps differently that bolts.
If the bearings look good, they can be reused if kept in order, however I'd go with new bearings.
The cylinder bores should be mic'd to check for any taper and wear before new rings are installed. If they check good, the walls can be honed with what we call a bottle brush to give the walls a fresh, cross-hatch finish without removing much wall material. That'll also save the piston to wall clearance.
You didn't say anything about your valve train setup, cam, heads, intake, etc., but my suspicion is 7000 rpms are way over the engine's power peak. Besides, for me, regular use of 7000 rpms for a 2 bolt block is over the top, especially if your also want the car to be a DD. To me it becomes an issue of When, NOT If (it's gonna blow).
Just my thoughts.
Jake
West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!
My dad had the motor rebuilt probably in 2006, but ran for like 100 miles. It was designed for drag racing. He somehow didn't need it anymore and it sat until i got it in march of 2009.
The motor has .030 forged pistons, 462 camel hump heads (redone in july of 2009), Ported, 2.02/1.60 stainless valve, dual valve springs with dampener, 1.5 full roller aluminum rockers, manley push rod guides, crane cams mechanical flat tappet oval track cam. Specs are 4200-7200 power band, 292/300 adv. duration, 256/264 @.050, 105 LSA, .545/.563 lift, double roller timing chain, dual 2.5" exhaust w/ short tube headers, single plane intake with holley 650 DP mechanical secondaries.
I believe the blow by is bad enough because it will cover the hood and engine bay with oil if i remove the breather and pvc. I did this test a few days ago, and only drove for 10 miles! what a mess. Plus, i constantly get oil in the intake, (even with a breather tank/ catch can for the pcv system) and my plugs are always dirty dirty.
Hope this is enough info for determining whether the rings are bad.
I will be taking my motor apart tomorrow anyways but i will take some pics and post just to see if they really are bad.
__________________ 1988 Camaro RS. Color - Faded blue. 19 years old, daily driver to work and school. Runs like a champ... 80% of the time.
well, i don't have a leak down tester, and i decided to take a shot in the dark.
I spent all day pulling my motor out and tearing it apart. I got lucky because 6 of the 8 piston rings' gaps were not 180* offset. Also, my bearings were worn a little so i am just going to replace all the rings, bearings, and install some arp main studs.
__________________ 1988 Camaro RS. Color - Faded blue. 19 years old, daily driver to work and school. Runs like a champ... 80% of the time.
It doesn't sound like you found your oil control issue though. The rings not being offset isn't the problem. You should consider taking the block to a machine shop for evaluation. It won't cost that much to have them take some measurements. It would suck to put it all back together and have the same problem.
I just can't get over that sound. 
