mcollinstn

I am gonna go thru my 502 carb motors. They have 375 hours on them and I am going to freshen them up and break them in prior to ProCharging them.

I am leaning towards Clevite H series, but would like feedback from others with an opinion. I hope to go another 250 hours before teardown and plan to run 6-7# of boost and expect WOT to be around 5300-5400.

Also, I do not plan to bore, but am going to scuff they cylinders with a hone and install fresh rings. Does anybody have preference on choice of rings in a Procharged motor?

I am leaning towards TGS gapless rings, but am concerned that the two-piece compression rings may be more delicate than a blower motor needs (I will have knock sensor, EGT, and O2 sensors). Any thoughts?

Also, who likes a particular grit for a freshen-up honing?


M

Dave F

You shouldn't have to hone. However if you do, a final hone with a 400 to 500 grit stone will produce a nice smooth finish.

I've been looking at Total Seal rings. The minimum I'd use is the TS1. This set has a molly top and a gapless second.
They say this set is good for supercharged.

They also have a set called Extreme. This set is for high boost. I was planning on calling them to find out the difference. Their website doesn't say what the top ring is made of.

Their Tech line number: 623 587 7400

DAVE

Dave F

Oh yeah. Clevite H is also a good choice in my opinon. Oliver, from Oliver connecting rods also has a good bearing.

Clevite has a really good web site. Lots of good info.

DAVE

mcollinstn

thanx

I'll call TS and get the lowdown.

M

vtec

mcollinstn:

Regard piston rings, check out this web site:

http://www.speedomotive.com/Building%20Tips.htm

vtec

mcollinstn

vtec - good info

I was planning on using the extrathick head gaskets to lower CR a tad (not anymore).

I was planning to use ZGS or TSG gapless second ring sets (not anymore).

If anything, I will be decking the blocks. Also will be using moly regular tension rings.

M

Dave F

What didn't you like about the Gapless?

mcollinstn

Go back and read the link that was referenced by vtec.
In the text of that site, it clearly represents that moly coated standard style ring sets are preferred for a performance engine. One of the reasons is that the gapless style use two thin and delicate interlocking rings in the second groove which is troublesome for two reasons. One reason is that they are more delicate and the second is that they do not allow any oil to pass them at all. Standard rings allow a small amount of oil to pass which is necessary for the proper longevity of a performance motor. Without some lube bypass, the top ring cannot dissipate heat (which is compounded by that ring going up and changing directions above the water jacket). As it builds up heat, it can drag in the bore which creates more heat, finally closing the ring gap up and locking the ring at the top of the bore and ripping the top of the piston off. The gapless style focuses on stopping pressure loss at the second ring, while the promary sealing ring is supposed to be the top ring. In tests it has shown that the second ring is not exposed to a significant percentage of the combustion pressure and that a solid seal there is not that helpful.

How much of that is fact and how much is opinion, I don't know. The oiling thing, though, makes the most sense to me in a performance marine application. If I were building a drag car, I believe that I would go with the ring set that made the most power. In my boat, though, I think I will give up a few hp for maximum ring, piston, and bore life.

If anybody has experience with gapless rings, pro or con, please comment.

M

Sylvester

I have used Total Seal rings for years on blown and unblown mtrs and have never had a problem some mtrs as many as 10 yrs since being built with no problem, H series bearings the way to go!................just my .02 of course.

mcollinstn

'vester

any particular series of Total Seal rings you would recommend? Use them out of the box or file the end gaps to a particular dimension? Any tricks?

M