GM Performance CNC'd LT1/L86 cylinder head flows?
04-12-2018, 04:33 PM
#1
Teching In
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Join Date: Jun 2017
Location: Central Texas
Posts: 15
GM Performance CNC'd LT1/L86 cylinder head flows? Has anybody ever found the CFM flows of the GM Performance CNC'd LT1/L86 cylinder heads? 19329839
https://www.gmperformancemotor.com/parts/19333525.html
These are the heads that are part of the GM Gen V LT1 hot cam kit. Not interested in the either the cam or the lifters, maybe just the castings and the valves. Supposedly can be had for $820 assembled, although I would prefer to ditch the valve springs and retainers for PSI beehives or PAC duals.
I'd be interested in getting rid of my DOD in my Yukon L86 by swapping out the AFM lifters and valve springs some day for the same Johnson 2110 SLR's and PSI 1511ML's that I run in my LS7, but if I'm going to pull my heads to get to my lifters, I'd feel compelled to increase those low flows (not even as good as L92/LS3 heads, they take a dump at about .550") with some additional porting. $$$
The GM beehives on the LT1/L86 motor are so cheap that I infer they are one up from junk! I saw a set of takeoff's from a Camaro SS that only had 20 miles on the odometer, for sale on Ebay for a paltry $25. I think they list for only $5 a pop.
But then I'd want to increase the duration and lift on the cam to take advantage of the new flows. Of course, I'd be more interested in low-end torque at the RPM's I'd usually see in my Yukon, and not want a high revving motor for that truck. $$$
A C5-R timing chain will fit as I've learned so may as well do that while I'm in there, too. ARP head bolts and I believe the ARP LS7 crank bolt fits the Gen V motors? And then I'm waiting on PowerBond for Gen V Race Series balancer, too.
https://www.gmperformancemotor.com/parts/19333525.html
These are the heads that are part of the GM Gen V LT1 hot cam kit. Not interested in the either the cam or the lifters, maybe just the castings and the valves. Supposedly can be had for $820 assembled, although I would prefer to ditch the valve springs and retainers for PSI beehives or PAC duals.
I'd be interested in getting rid of my DOD in my Yukon L86 by swapping out the AFM lifters and valve springs some day for the same Johnson 2110 SLR's and PSI 1511ML's that I run in my LS7, but if I'm going to pull my heads to get to my lifters, I'd feel compelled to increase those low flows (not even as good as L92/LS3 heads, they take a dump at about .550") with some additional porting. $$$
The GM beehives on the LT1/L86 motor are so cheap that I infer they are one up from junk! I saw a set of takeoff's from a Camaro SS that only had 20 miles on the odometer, for sale on Ebay for a paltry $25. I think they list for only $5 a pop.
But then I'd want to increase the duration and lift on the cam to take advantage of the new flows. Of course, I'd be more interested in low-end torque at the RPM's I'd usually see in my Yukon, and not want a high revving motor for that truck. $$$
A C5-R timing chain will fit as I've learned so may as well do that while I'm in there, too. ARP head bolts and I believe the ARP LS7 crank bolt fits the Gen V motors? And then I'm waiting on PowerBond for Gen V Race Series balancer, too.
04-17-2018, 08:35 AM
#4
If you would like to give us a try we have ours at 366/244cfm and is what the FireBall camaros run.
06-27-2018, 11:08 AM
#6
I would answer your question with results but for some reason I can't copy and paste to here. The CNC heads aren't terrible but they aren't that good either.
My heads flow above [email protected] on the intake and above [email protected] on the exhaust. I take 13cc's out of the runners. My dyno and track numbers back the flow numbers up.
My heads flow above [email protected] on the intake and above [email protected] on the exhaust. I take 13cc's out of the runners. My dyno and track numbers back the flow numbers up.
