yenkomike

iTrader: (2)

my 173.000 mile 6.0 had .024 to .026 gaps. I just cleaned it all up with easy off oven cleaner and put it back together. runs great. 10# boost no blowby.

2muchboostNY

iTrader: (8)

^^^Thanks for the video that was actually helpful for me. LOL love Denmahs approach to things.

69-chvl

iTrader: (11)

All this talk made me very curious - I just took a piston out of a 77k (supposedly) LQ9 and the gaps measure 19 top and 30+ on the botton - wow thats alot.

I think a distinction needs to be made whether race gas/e85/pump is being used with stock gaps.

So is the consensus to open the gaps if PUMP GAS is being used???

RatCityRex

iTrader: (3)

Open gaps no matter what fuel is used if it's going to be boosted.

So some time back There was a article about ring gap and blow by. They started with a sbc i believe, with stock gaps and they did a dyno pull. Pulled the motor apart and opened the rings .010 more then reassembled and did another pull. And then repeated this over and over. They didn't start to see excessive blow by until they reached the .080ish range. Not with that being said this was also on a NA motor. Boosted is a little different but still the same principle. Better to have your rings on the looser side of things then to have them to tight and break ringlands. I'm about to put my lq4 into my 66 nova and boost it. My top ring is .030 and my second ring is .038 so we will see if there is any blow by. I doubt it. Won't have it running until probably November but I'll post back up in here and let you guys know how it's doing as far as blow by.

Forcefed86

iTrader: (4)

Even with a Junker I’d suggest cleaning them up and checking the gap for sure.

I ran 28/32 (ish) on my first 5.3 LS build. I got quite a bit of blow by in boost. Ran/drove find out of boost with no noticeable blow by. Would hose down the engine bay pretty good in boost. Even with a catch can. I also blame my many oil leaks on the blow by. I see zero reason to run over .0060 and .0065 X bore unless you are running a high expansion alloy piston at retardo boost levels. OE pistons don’t’ expand much by comparison, and will fail before having gap issues at .0060/.0065 levels IMO.

STEEPSS

iTrader: (30)

Well then, stay tuned. Because i'm not taking it back apart!

RatCityRex

iTrader: (3)

I know a lot of people get excited once there boosted car is all together and they have it ready to rock, But I know I have seen lots of people rocking around with the stock pcv setup still hooked up onced boosted.

I know this isn't Hondas, But Hondas hate crank case pressure and that's one of the leading causes to broken ring lands with them once they are boosted.

Now i've never personally tested the stock limits of the pcv setups on ls motors. But I can tell you that if your crank case ventilation isn't addressed once boosted it WILL cause blow by.

RonSSNova

iTrader: (3)

Can you give an example of a good way to vent?
I'm just running the valve cover vents open to atmosphere. I've gathered a spare set of valve covers to play with.
I do have some white cloth over the vents. Laugh, but very little mist comes out.

RatCityRex

iTrader: (3)

The first mistake people make is they leave there pcv valves still hooked up. Once they fail, boost blows past them and will pressurize the crank case. Brake booster check valves work great in the place of pcv valves. Better off just venting to atomo like you have now.

RonSSNova

iTrader: (3)

That's funny. The anti evac system.
I may run some lines to a catch can. Just to collect the mist.

Thanks

Forcefed86

iTrader: (4)

Exhaust evac kit or Elec vac pump is the best way IMO. I use an electric emissions pump on a boost switch for mine. Works great.

RonSSNova

iTrader: (3)

Good ideas

Ron

RatCityRex

iTrader: (3)

Most the time just letting the engine push it out is fine, but you can free up some horsepower with a evacuation pump like all the race cars run. For us poor folks, a vented catch can that is filtered works good. I don't like sealed cans that reroute back to the intake on a turbo.

turboventura

I need to build a catch can cause oil is dripping off my breather onto the header. My local shop said to put steel wool in the can cause it traps the oil and let's just the air out. Obviously I wouldn't use this to return oil to the motor, just drain every now and then.

RatCityRex

iTrader: (3)

Steel wool works ok, but only if your your can doesn't have a return line to your pan because the water vapor in the can will make the steel wool rusty. And the last thing you want is to put that back into your engine. I've always just made baffles inside my cans to direct the oil vapor down and then drained it ever so often. Ive seen stainless steel wool you could always use a few nylon scrubby brushes from the dollar store...lol if you were gonna do a drain back style.

Forcefed86

iTrader: (4)

I've used scotch brite, or SS or brass SOS pads so it doesnt' make a rusty mess.



Fuel cell foam actually works really well too (and it's cheap!). I switched over to this recently on my VAC pump setup. I had a bunch of foam blocks I removed from my cell to run E85.

http://www.ebay.com/itm/RJS-20217-Fuel-Cell-Safety-Foam-8-x-8-x-4-Gasoline-Each-/331266145928?pt=Motors_Car_Truck_Parts_Accessories&hash=item4d21003e88&vxp=mtr

STEEPSS

iTrader: (30)

I added a -10 fitting to each valve cover prior to the turbo setup. Run both to a single can, and it seems to do fine!

RatCityRex

iTrader: (3)

Fuel cell foam is a great idea.



A lot of people (myself included) dont have the capability to weld alum and don't want to spend the money to pay someone to weld it. That's why I'm gonna rock the fittings jb welded in the oil fill cap.

69-chvl

iTrader: (11)

Just want to throw this out there regarding gaps....

I pulled all the pistons out of this LQ9 I'm working on, and all the bottom rings are .030+, but the top range from .017 to .020. Glad I took the time to pop them out. I do want to say that you really need to have a ring squaring tool to properly measure rings gaps. Using a piston does absolutely nothing other than leave the ring crooked in the bore and REALLY throws off the measurements. A ring may appear to have clearance until that sucker is squared-up - then it gets mysteriously tighter !!!!

vht

I used to use a piston with a oil ring on it. Pushed it down to the ring so it would sqare it up.