In need of help understanding head casting
In a perfect world where money is no object I'd buy a set of nice aftermarket castings port them and go to town but in the past I have had nice results in my opinion having stock ls1 castings ported. I had a set of 241s done by Lloyd Elliot and have the stock 853s sitting on the shelf and not much interest in buyers.
So between the gm castings 853, 241, and 243 (maybe there's others I don't know off hand) what makes any one of them a better starting point? Are there restrictions that will limit just how well these will flow in ported form against one another? I understand the 243s are the best among the three and are a popular starting point but if I'm going to port and mill them really is there anything holding me back by using what I have and not spending the money on another set of heads?
In a perfect world where money is no object I'd buy a set of nice aftermarket castings port them and go to town but in the past I have had nice results in my opinion having stock ls1 castings ported. I had a set of 241s done by Lloyd Elliot and have the stock 853s sitting on the shelf and not much interest in buyers.
So between the gm castings 853, 241, and 243 (maybe there's others I don't know off hand) what makes any one of them a better starting point? Are there restrictions that will limit just how well these will flow in ported form against one another? I understand the 243s are the best among the three and are a popular starting point but if I'm going to port and mill them really is there anything holding me back by using what I have and not spending the money on another set of heads?
If your question is "should I port and run 853s?", Answer is: They will perform well, although 243s would be better. If I were you, I would just buy a set of PRC LS6 heads ready to bolt on a go. It's going to cost you about a grand + to have the 853s rebuilt and CNC ported. Heck a set of 5.3 heads will suit you well too!
http://www.c5registry.com/documents/ls6/page4.htm
Ron
Thanks for the input.
http://www.c5registry.com/documents/ls6/page4.htm
Ron
Thanks for the input.
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Ron
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Truthfully that was the question but you were the only one so far to say stick with what I've got.
Truthfully that was the question but you were the only one so far to say stick with what I've got.
I have never heard of Lloyd Elliot...so I can't vouch for them, but Texas Speed and AI heads are widely used and have dyno #s to prove their superiority. Some builds have seen close to 500RWHP with these heads.
I have never heard of Lloyd Elliot...so I can't vouch for them, but Texas Speed and AI heads are widely used and have dyno #s to prove their superiority. Some builds have seen close to 500RWHP with these heads.
Lloyd Elliot is not very well know in the LS1 world, but he's basically the "go to guy" when it comes to anything LT1.
How much more power is a well-ported 243 vs a well-ported standard LS1 head? I hear "more" and I hear "similar" and I've even told some folks that they would be same or similar at full tilt ported. Can we get a number or % or similar?
(I know the real LS6 243s have specific valves so let's assume those were placed in the LS1 head upon porting or that both got upgraded valves)
How much more power is a well-ported 243 vs a well-ported standard LS1 head? I hear "more" and I hear "similar" and I've even told some folks that they would be same or similar at full tilt ported. Can we get a number or % or similar?
(I know the real LS6 243s have specific valves so let's assume those were placed in the LS1 head upon porting or that both got upgraded valves)
Seems to me ~5% difference when ported/valved/cc'd similarly. What do you see? In "max effort" 5% can be huge so I'm not discounting it; just want to get to a conclusion since this subject seems to come up often..surprisingly often for 10+ year old castings!
https://ls1tech.com/forums/dynamomet...o-results.html
https://ls1tech.com/forums/dynamomet...m-results.html
https://ls1tech.com/forums/dynamomet...ck-valves.html










