I have a growing theory about using synthetic in a stock boosted motor with miles on lately due to 2 reasons. Recently I had a b20vtec(stock block, arp h.s., cometic mls, p30 stock head, and hondata) in my em1 that I put a PeakBoost(cheapturbo.com - Awesome Kit) Turbo kit on and I was only running a safe 5 lbs putting down 280whp and on cold nights up here in wisconsin getting to about 8 lbs and pulling like hell. I got about 8k miles on the kit after putting it through about anything and tried out R-P synthetic 5w30 and didn't last more than 50 miles that same night without melting piston #4. I always wanted to blame it on the oil, but I was never quite sure about it until a customer of mine with a del sol(stock gsr and same turbo kit running 9lbs @ 320whp) came to the shop (after putting 15k miles on the motor) to tell me that he was blowing smoke extremely bad out of his motor. After tearing the motor down we found out he had broke ring lands in pistons #3 and #4. I couldn't figure out why his motor may have done this until he told me that he had run full synthetic in it about 10 miles before it blew up.

After doing my reading in past posts, a lot of h-ters estimate that the synthetic oil lubricates too well and cleans up the walls alot more. Is this correct and has this happened to anybody esle?

 

It would be very hard to prove that, but I have heard of cracked pistons running fine and not burning oil until the owner put full synthetic oil in, and then **** hit the fan. I have a built turbo B18c with 700 miles on it and I'm not sure about putting synthetic in there either.

 

This is what I like to hear, anybody else with good knowledge?

 

I've run full synthetic in a boosted stock SOHC for over 35k miles (it's been on synthetic for life).. no a problem. Ran it in my GSR when stock and it too ran fine till I had a stupid moment with the boost controller. I can name dozens of people with stock engines who run nothing but pure synthetic as well with no problems.

My .02


Modified by VTC_resurected_CiViC at 11:50 AM 12/28/2004

 

This is a good topic. I would like to hear more information on this subject.

 

I could see this being a cause for concern if the motor was a fresh rebuild, as the rings haven't had a chance to properly seat or perhaps it being an issue of improper break-in, but to attribute two motors with bad ringlands due to synthetic oil is unsubstantiated. Correlation is not causastion. I would persue other probable reasons as to why the ringlands failed. I wouldn't completely discount your theory though.

 

I've been running mobil 1 10w-30 for about 12k miles now with no problems thank god

 

I ran synthetic after first 500 miles on ls/vtec for 30,000 miles.

Started detonating in its later days though... Fuel was on the edge and this is what ended the motor. Detonation caused one of the pistons to warp a little... I took it apart on a gut feeling and discovered the small defect before the motor actualy blew... looking at it from the top of the deck it looked fine, pulled pistons out and noticed a small raise in one of them... Posted pics of it on here but ill have to find them.

Was running stock 2000si ecu, and prelude injectors..... never tuned but pushed the car to a 13.9 (2000 si, full interior) on azenis.

Really dont think synthetic is the culprate