Re-Ringing pistons Questions

Onefast99gsx · 12-08-2006

Hey guys- time to start thinking about '07. As some of you know the last time i went out to the track i spewed oil all over the motor due the dip stick popping out. It happened 2 more times after that, even with a new dipstick. Compression is lower than what most people report what theirs is. I'm low to mid 140 lbs. Motor has about 95k on it. Up until i parked it for the winter, i jury rigged it by clamping the dipstick in the tube. I hate the fact that it's cobbled up. I vowed not to race it next summer unless i fix the excessive blow by issue.

So, I talked to a machine shop locally and there is a guy that will assist me. I want to re-ring the pistons with the block in the car and crank untouched. The plan is to seal up the crank during the process. I mostly only need him for ensuring a good cross-hatch pattern in the cylinders.

So as long as i'm in there, i figure I might as well replace the rod bearings. Then I was thinking that i might as well replace the rods as well with Eagles or something. So my questions are,

#1 which rod manufactures rods will work with the stock 2g pistons?

#2 if the rods are a matching set, can you put them in without balancing the engine? I would think so, but I wanted to ask anyway.

Thanks much for any helpful advice.

niterydr · 12-08-2006

I would recommend to still balance the system. Most aftermarket rods are within a few grams of each other, but sometimes the weight is shifted.
We recommend and use King or ACL bearings in all of the motors we build.
None of the aftermarket rods will work with stock 2g piston. The stock 2g piston is a press-fit, setup, the aftermarket rods are floating pin...
I'd say just pull the motor and rebuild it with all forged units and save yourself the hassle.

**JET** · 12-08-2006

Yeah, if you are pulling the head off then yanking the engine isn't all that much more work. The machining will be better because it goes in the shop.

140 isn't that terrible, either just re-ring it or pull the engine out and do it right. Be sure to do valve guide seals while you are at it, they may be a big part of your problem. With only 95k miles, it is odd that you would get ring blowby.

Onefast99gsx · 12-08-2006

Thanks JET & Niterydr- I want to avoid as much as possible, pulling the motor. Unless you mean pull it, but leave the crank and everything else in tact. Because if the cranks gotta come out, then i might as well do a complete engine rebuild and I don't want to go down that road until it's mandatory (6 bolt swap)... I just rebuilt the head last summer ('05) with all new valve seals and was extremely careful when putting them in not to damage them. I understand you that no aftermarket rods will work with the stock OEM pistons. I don't mind just doing all the work just to change out the rings & rod bearings with new. I have time but doing a rebuild is something I just can't afford at the moment due to house hunting. I would expect that aftermarket rods, pistons, bearings and a complete engine rebuild would be at least $1500+.

So i guess I'll just stick to re-ringing the OEM pistons, hone it and put some new rod bearings in. I guess as long as the head is off, i might as well put some new valve seals in just for the sake of, it's off anyway. Maybe in 2008, i'll look at a 6 bolt swap but I just can't do it right now so that's why I opted for this route for now.

Thanks.

carltalon · 12-08-2006

If the cars still running and has 140 + across the board Id recomend leaving it and saving your money for a built 6 bolt. your better off doing it right the first time. A reringing will get you by for now till next year when you want to throw A gt35 + on it and you blow your rods. Just my 2 cents, All I know is a properly built Eagle/weisco 6 bolt can take alot of abuse.

Enes · 12-09-2006

Sorry to jump in this thread but its similar to my situation, last time i checked my compression it was still 170 to 174 on all cyl. but i was still geting blow by.
would hate to rebuild the engine if its just the valve seals wouldn't amount of blowby affect compression? if you had more blowby = lower compression..

where i'm getting at is if you do your valve seals wouldn't that increase your compression a bit too?

**Goat Blower** · 12-09-2006

Quote:

Originally Posted by Enes

Sorry to jump in this thread but its similar to my situation, last time i checked my compression it was still 170 to 174 on all cyl. but i was still geting blow by.
would hate to rebuild the engine if its just the valve seals wouldn't amount of blowby affect compression? if you had more blowby = lower compression..

where i'm getting at is if you do your valve seals wouldn't that increase your compression a bit too?

No. Compression is the highest amount of pressure at TDC on the compression stroke with all valves closed. Blowby going by the valve seals occurs when the intake or exhaust valves are open so it doesn't affect your compression.

You can replace your valve seals without taking your head off, but it's a tedious procdure. It involves having that particular cylinder piston at TDC and putting rope in the cylinder to keep the valves closed or pressurizing the cylinder with air to keep the valves closed and popping the spring retainers with a O2 sensor socket. It's probably best to just take the head off and replace your timing belt components while you're in there though.

Pushit2.0 · 12-11-2006

I would say try a leak down test to see where the pressure is going, also check your PCV valve if that is bad boost pressure from you intake manifold could go to your crank case.

~John

Onefast99gsx · 12-11-2006

Yep, I'm gonna do a leakdown test. I have borrowed one from a garage. I just need to get a decent air compressor. Btw- my PCV was replaced with just a straight thru fitting. Both fittings on the valve cover goto a JAZ catch can. I took the hoses off the catch can and i could blow into each one of them without any restrictions. I know it works because i drain the JAZ catch.

Thanks.

sleepydsm · 01-14-2007

On my old car I honed the block in the car, re-ringed the cylinders, and replaced one piston. I used motor oil for lube on the cylinder walls while honing, taped off the coolant and oil passages, then scrubbed the heck out of the cylinders with warm soapy water to get any abrasives out. Re-ringin was easy, just make sure you put the ring gaps in the proper spots. Definately put a rubber hose or something over the rod studs so u dont scrape the journals.

b00stcreep21 · 01-14-2007

I can honestly tell you that it will almost be as much work to pull the head off, as compared to pulling out the motor. It's really not that hard. Do it right the first time so you don't shoot yourself in the foot later on down the road. Pull it out and bring the block to the machine shop....

Onefast99gsx · 01-15-2007

Thanks for the suggestions guys.. Last Thursday night I finally did a leak down test. I used a 100psi for my input source. I had a 10% loss in 2 cylinders, 4% loss in a cylinder and the #2 cylinder was the worst at 25% loss. That would clearly explain why the dipstick is shooting out. I want to re-ring it but I wish I could do something else while I was in there like changing the puny 2g rods. Nobody seems to make an aftermarket rod for the stock pistons though. Any rod I've seen is for a floating type wrist pin. Can't afford a complete rebuilt of a 6 bolt anytime soon. Was hoping to just change the 2g rods for added insurance.

Pushit2.0 · 01-15-2007

Try a new dipstick then, 25% is not that bad.

~John

Onefast99gsx · 01-15-2007

Really, 25% isn't bad? On the instructions of the MAC Tools tester, I believe it said anything over 10% is cause for concern.

I did buy a brand new dipstick last fall. Boosted her to about 26psi again and it popped out spewing oil all over the motor again. I was not happy. For the last race, I wired it in there so it wouldn't come out but that was merely a bandaid fix. I want to fix the source of the problem.

Believe me, I don't even want to re-ring the motor! Just seems like alot of work for what the project actually is. I thought about putting bigger fittings on the valve cover like a 6 or 8AN fitting size and into a different catch can than what i have. Any thoughts on this?

tim · 01-15-2007

25% is not that good. 10% is normal and anything more than 20% should be addressed, especially in a performance car. The biggest thing, like compression, is that you dont want a huge difference between cylinders.

My old s10 had 80% leakage in one cylinder, but I really didnt give a shit cause it still ran great.

Just curious, was it leaking through the rings? Did you check to see where the air was escaping from? I would assume it was rings cause the whole dipstick ordeal but it could be other things.

Onefast99gsx · 01-16-2007

I'm going to retest the #2 cylinder. I did another compression test tonight with the engine slightly warm. I came up with:

#1 150
#2 143
#3 149
#4 155

I have a hard time believing that #2 would be 25% loss and still be fairly close in compression to the other cylinders.

tim · 01-16-2007

Quote:

Originally Posted by Onefast99gsx

I'm going to retest the #2 cylinder. I did another compression test tonight with the engine slightly warm. I came up with:

#1 150
#2 143
#3 149
#4 155

I have a hard time believing that #2 would be 25% loss and still be fairly close in compression to the other cylinders.

It can happen. Compression is rather confusing.

While you are doing your next leak down test look for the leaks. If your coolant is bubbling, then you know what to look for. If you are hearing a hissing through the exhaust or intake then you have a burned valve.... You know the drill, find out where this leakage is present. It will tell you a lot about your engine.

Onefast99gsx · 01-24-2007

Hey guys- I just talked to a guy today over email. He knows a few things but he's not an engine genius. He's got me all worried now that re-ringing my motor might not do anything for me. As a matter of fact, he said it might make it worse because you have to hone it out. The head is off, pistons will come out over the weekend. The walls look beautiful. Still has a very nice cross hatch pattern even after like 90k miles. You think re-ringing is a waste of time and can make my blowby even worse? I really don't want to get buried in this project by having to get it bored out, new pistons, rods, bearings etc. The most I wanted to do is buy rings and rod bearings.

What are your thoughts or experiences on re-ringing a motor? Did it help or make it worse.

Thanks.

Onefast99gsx · 01-24-2007

Just talked to a more experienced person. He said once i get the pistons out, get the bore gauge from my local machine shop and check for taper. If they are good, then he said don't worry. Honing, takes out very minimal. It's only to remove the glazing mostly. I would have to think my cyls are good because i rotated the motor over and the cyls don't have a single score mark. Still have nice hatch patterns even after 90k miles.

**Goat Blower** · 01-24-2007

Follow the second person. Putting in new rings even with a rehone is just fine if scoring is minimal, which it usually is. I've seen virtually no wear on motors with over 150K miles on them.