Need expert l92 help
Need expert l92 help Here's my dilema guys. I have a built 408 now and I need to know my best plan of attack for more power.
The set up:
iron 408
4.030 bore
4 inch stroke
6.125 rods
Mahle -12 cc pistons
LPE GT-11 215/231 and .631/.644 118LSA
PRC stage 2.5 heads (like 305cfm flow)
I want to run L92 heads, but I don't know if the valves will clear the pistons with the cam I have. Is any one else running the L92's with these mahle pistons?
Then, if I shouldn't have any clearance issues, what would happen if i went with a more aggressive cam in the future. Would I be better to keep the heads I have or stick with the L92's.
See where I'm going with this.
The set up:
iron 408
4.030 bore
4 inch stroke
6.125 rods
Mahle -12 cc pistons
LPE GT-11 215/231 and .631/.644 118LSA
PRC stage 2.5 heads (like 305cfm flow)
I want to run L92 heads, but I don't know if the valves will clear the pistons with the cam I have. Is any one else running the L92's with these mahle pistons?
Then, if I shouldn't have any clearance issues, what would happen if i went with a more aggressive cam in the future. Would I be better to keep the heads I have or stick with the L92's.
See where I'm going with this.
I was looking at that cam for my setup. The intake valve events looked great, and I have always liked the LPE cams with the low overlap - they drive like stock and still make decent power.
I think one of the tricks to the L92 head is going to be opening the intake valve late. That is just a hunch though, based on talking to old time gear heads locally who refer to it as a "lazy port" head.
-Geoff
I think one of the tricks to the L92 head is going to be opening the intake valve late. That is just a hunch though, based on talking to old time gear heads locally who refer to it as a "lazy port" head.
-Geoff
From what I understand, the L92's make better power than almost every head out there. Maybe I'm wrong, but it seems like a killer head. It just seems like everybody needs to flycut when using this head.
Fly cutting? I'm getting my L92 heads milled and cleaned up (Chambers/Exhaust ports)right now. When they come back I plan on flycutting if I don't have enough p/v clearance.
I plan on running a TRAK cam, .040 gaskets, and the heads will be shaved .030, Manley pistons (.010 over the deck). The max intake valve the pistons will accept is 2.08 and the L92 has 2.16 intakes (and they are offset towards the center.
I hope that I have enough clearance as it is , but if not at least I have a plan.
Bob K.
I plan on running a TRAK cam, .040 gaskets, and the heads will be shaved .030, Manley pistons (.010 over the deck). The max intake valve the pistons will accept is 2.08 and the L92 has 2.16 intakes (and they are offset towards the center.
I hope that I have enough clearance as it is , but if not at least I have a plan.
Bob K.
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It isn't possible to fly cut while having the engine in, is it? Thats the main thing i don't want to do again is pull the engine and rods and pistons out. If thats the case, I will just buy pistons that will work.
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Originally Posted by gen3performance
Here's my dilema guys. I have a built 408 now and I need to know my best plan of attack for more power.
The set up:
iron 408
4.030 bore
4 inch stroke
6.125 rods
Mahle -12 cc pistons
LPE GT-11 215/231 and .631/.644 118LSA
PRC stage 2.5 heads (like 305cfm flow)
I want to run L92 heads, but I don't know if the valves will clear the pistons with the cam I have. Is any one else running the L92's with these mahle pistons?
Then, if I shouldn't have any clearance issues, what would happen if i went with a more aggressive cam in the future. Would I be better to keep the heads I have or stick with the L92's.
See where I'm going with this.
The set up:
iron 408
4.030 bore
4 inch stroke
6.125 rods
Mahle -12 cc pistons
LPE GT-11 215/231 and .631/.644 118LSA
PRC stage 2.5 heads (like 305cfm flow)
I want to run L92 heads, but I don't know if the valves will clear the pistons with the cam I have. Is any one else running the L92's with these mahle pistons?
Then, if I shouldn't have any clearance issues, what would happen if i went with a more aggressive cam in the future. Would I be better to keep the heads I have or stick with the L92's.
See where I'm going with this.
I just put together my 408 with a comp 231/235 110+0 LSK, -9cc diamond pistons, 65cc chamber, .041 head gasket with REV 2.160 I and 1.6 E valves and had plenty of P/V clearance.
I have the same pistons and L92s milled .040. Because of the size of the intake valve I am not sure it will fit into the valve pockets so I am going to measure. I suggest you do, also.
Last edited by See5; Jan 25, 2007 at 06:24 AM.
lol...its amazing how most of us end up choosing the same or similer set ups. i mean its common but since these heads havent been out for very long, we are all takin a chance. up untill a week or so ago i hadnt seen any problem with the clearance that everyones all of sudden talkin about...i got worried cause i have had them for a little over a month now. im doin the L92's on my 402...but i have -15cc Diamonds cause im going forced induction. its my understanding that if i dont run a huge cam i should not have any P/V clearance issues.
Originally Posted by gen3performance
It isn't possible to fly cut while having the engine in, is it? Thats the main thing i don't want to do again is pull the engine and rods and pistons out. If thats the case, I will just buy pistons that will work.