WKMCD

iTrader: (2)

I had my C5 out today and got a little whiff of coolant in the exhaust when I stopped. Coolant level looked OK but about 100 miles later the low coolant light cam on so it 's looking like the 402 is now on the front burner.

I've got the L76 manifold and the L92 heads are on the way. The ls2 402 is in process. I want to start assembly in the next ten days or so.

The problem is there are no proven cams out there for this combination so this is everyones opportunity to help me spec a cam. We've got to start somewhere with these new heads. I'l take one for the team.

I'm currently running an LS1 H/C car with a 230-236 112 +2 XE-R, PRC 2.5R heads 62cc, 90/90, 3.90's, M6, etc/etc/etc and SD tune. I want to stay close to the same drivability. The car will never see a track but is used for trips, ocassional commuting and sometimes DD during nice weather and hard flogging every chance I get.

Based on the stock flow numbers Comp Cams is suggesting a 228-240 114. I really prefer a tighter LSA for more under the curve power. The 402 will use 2cc pistons which should net about 11.2:1 SDR. I want to keep the DCR mid 8's. We do have 93 octane here. Emissions not a problem.

Any and all suggestions and recommendations appreciated. If you can please explain your choice a little.

Vendors very welcome to play along. Let me know what you would offer.

Thanks

Kevin McD
Northern VA

98blackSS

Haven't you had issues with this coolant stuff before? What was wrong last time?

WKMCD

iTrader: (2)

Cometics before...Not sure this time. Before was about 8k miles ago... Not sure what it is this time...Oh well, this just accelerates the new setup.

JBsZ06

Can't give you an opinion on the cam but I'm checking in because it sounds like an awesome way to go...

Can you give us a cost estimate so far? and then again when complete.

Thanks and I think your choices here are the hot ticket.

JB

Wnts2Go10O

iTrader: (12)

with the intake/exhaust ratio, a split is your friend ~6* or more.

Stang's Bane

iTrader: (22)

I think you will get alot more accurate suggestions after you get the Intake and heads flowed together. Are you planning to do any port work on the heads or leave them stock?

WKMCD

iTrader: (2)

They will probably go on stock for now. If people are showing big numbers with them ported - I do that later. No one is ready to port the heads yet.

slow trap

iTrader: (22)

i've heare those heads are alittle weak on the exhaust port so as allready stated you will probably need 6-8 * more duration on the exhaust side.how about something like a 240/248 on xer lobes ground on a 110 ?

Stang's Bane

iTrader: (22)

I would have to do the I/E ratio, but I think it is similiar to an LS7 head. An unported LS7 likes quite a bit of split at least 15*. I am not even gonna try to suggest specific duration #'s, but I thought that this might help for FWIW.

corvettetimmy

Thats awesome, looks like a revival of the TPI heads on a 402 . J/k Im sure you meant l92.

WKMCD

iTrader: (2)

Thanks, your right about the split. I really think it's going to be 10-12 degrees.

WKMCD

iTrader: (2)

OOOPS! L92

1CAMWNDR

iTrader: (21)

I would say a 10° split or so.
How about a Comp XFI:

286° 242° 156° .604"
302° 253° 166° .615"
110° LSA +4° (106° ICL)
Intake valve closes at 69° ABDC

Or how about a milder ramp Xtreme RPM High lift:

297° 244° 160° .595"
307° 254° 169° .595"
110° LSA +4° (106° ICL)
Intake valve closes at 74.5° ABDC

The problem with those cams in the overlap at .050".......27.5° and 29° respectively .

SStrokerAce

iTrader: (2)

A stock head is going to need the most split, and more than 10°

Bret

DONAIMIAN

iTrader: (18)

Ehh its people running 30ish in stock cube motors. Im sure thoes 402 cubes will soak that up.

1CAMWNDR

iTrader: (21)

I see. I am just used to trying to keep the overlap around 8°-10°......but that is for cam only set-ups I think.....

WKMCD

iTrader: (2)

Thanks guys. I think it's going to be 12-14 degrees of split with the stock L92's. The disparity between the intake and the exhaust is huge. Pretty sure that I want to keep the intake fairly mild to take advantage of the big flow numbers and run the exhaust out to a more conventional 402 number.

Also want to keep the intake closing pretty low ABDC for some great under the curve power. The perfect cam will let me stomp on it in 3rd at 3k and light up the tires. I'm not looking for the absolute highest high RPM RWHP.

Just a reminder, this is not a track car. I use it as a DD on nice days and take it on trips and around town. I do pound on it regularly though. Currently running a full H/C w/ 230-236 112 XE-R and I like the drivability I have now.

Let's keep this dicussion going.

SStrokerAce

iTrader: (2)

With what you have now for a cam you can definately tolerate the right sized cam for what you are going to run in the L92 402. The problem without porting the exhausts on a L92 head is that you are going to have a bad E/I ratio, that doesn't mean everything when it comes to the camshaft split but it does play into it.

Bret

WKMCD

iTrader: (2)

Comp suggested a 228-240 113 XE-R based on the stock flow numbers and the conversatoin I had with them..

Maybe it's a starting poing for discussion.

SStrokerAce

iTrader: (2)

I don't really discuss cam specs, that's for LS1tech and once everyone becomes a cam designer I move on to something more interesting, hence the L92 stuff. IMHO I think they are not taking the valve sizes and cubes into account if that's the cam they come up with, from some preliminary numbers I was working on before it's not close to what I came up with.

Bret