blk00ss

iTrader: (66)

Heres the rundown guys. I just pulled the LS2 404 from my car due to the blander spinning on the crank. For the second time. So while i have it apart I'm either going to part it out and start fresh, or try and get the crank fixed and key it with a new ATI damper. Also going to do new rings and bearings.

So far everything looks good inside the engine. The mains will probably need to be turned due to very finite scratches. Rods looks good as do the pistons. Cylinder also looks excellent minus the little bit of wear from the stroke side of the piston. Currently the pistons have Total Seal gapless rings set at .024/.018. From day one the engine has smoked and consumed a good bit of oil. But has always ran strong. Making 500 to the tires with patriot stage III heads. I sold those heads and installed the Trickflow 235's and lost 12hp, making only 487.

So there lies the big question. Why did the heads hurt the power? Is it because the 4.010" bore isn't enough for the 235's? Would a 4.030 bore really help that much? Also would a 4.060 help even more? But will that work with a 200hp shot of nitrous? And would I still have the same oil control issues?

What set of rings could i go with to help control the oil issue? I want to make at least 530 to the tires.

Any recommendations?

blk00ss

iTrader: (66)

Bump.

LLLosingit

iTrader: (4)

Were the combustion chambers the same size on both sets of heads?

blk00ss

iTrader: (66)

The patriots were 70cc and the TFS have 66cc.

LLLosingit

iTrader: (4)

Here is my theory, I think the 12hp you lost has nothing to do with the heads, I think it's due to ring seal. I don't know how long it was between dyno sessions but if you built the motor and hit the dyno then and made 500 to the tires then ran it for awhile and rings never did break in properly then they probably were worse by the time you changed heads and hit the dyno the the second time. With bad rings comes lower compression and contaminated combustion both would explain a power loss. Don't blame the brand/type of rings, They have been used for years with good results. Could have been poor break in procedure, Bad cylinder prep or installation.

LLLosingit

iTrader: (4)

I would have the bore checked and see if it needs an over bore to clean it up and go from there. If you can get by with a hone and new rings then I'd go that route and save the bore for when it's really needed. If you go 60 over now then what options are you going to have down the road? If your re-ring it and get a good seal you'll gain that 12hp back and then some as it breaks in completely.

blk00ss

iTrader: (66)

I've decided to go a completely new route. Something in the 427-434 range.

z0vette

Am no expert but I Think the TF 235 heads are having the bigger/heavier valves than what you had before. That might hurt the power too if your cam lobe isn't set properly for the heavy valves.
2- ring sealing issue as the guys said.
I have used the prc237 with a great success with that bore and made 570rwhp and 548rwt through M6. My compression was 11.6

blk00ss

iTrader: (66)

I've ordered a 445 from LME today. And going to get the heads freshened up. And recommendations? I really want to have Mamo do them, but the shortblock really put a dent in the funds lol.