Help to I.D. head porting
#1
Help to I.D. head porting
I picked up a set of cnc ported 799 heads. Unfortunately there is no obvious marking to suggest who did the porting work. These have passed through several people and were claimed to be TSP Stage 1 but they are not marked as TSP says they would be. Valves appear to be stock gm, stock sizes.
Only non-factory markings I can find are: Letters MKN on one end of each head and PG515 on the casting number pad.
Only non-factory markings I can find are: Letters MKN on one end of each head and PG515 on the casting number pad.
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G Atsma (11-10-2019)
#7
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#8
I got a response back from WCCH, not their work and no suggestions on whose work it may be.
I sent an email to AI, awaiting a response from them.
I did disassemble and start cleaning them up hoping to find some other markings. No luck with that but it appears there has been significant work to the combustion chambers. Is that normal for a stage 1 porting?
ported 799
Stock 243
I sent an email to AI, awaiting a response from them.
I did disassemble and start cleaning them up hoping to find some other markings. No luck with that but it appears there has been significant work to the combustion chambers. Is that normal for a stage 1 porting?
ported 799
Stock 243
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62nalide (11-12-2019)
#9
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I got a response back from WCCH, not their work and no suggestions on whose work it may be.
I sent an email to AI, awaiting a response from them.
I did disassemble and start cleaning them up hoping to find some other markings. No luck with that but it appears there has been significant work to the combustion chambers. Is that normal for a stage 1 porting?
ported 799
Stock 243
I sent an email to AI, awaiting a response from them.
I did disassemble and start cleaning them up hoping to find some other markings. No luck with that but it appears there has been significant work to the combustion chambers. Is that normal for a stage 1 porting?
ported 799
Stock 243
#10
TECH Senior Member
While not radical, I wouldn't call it Stage I. Usually chambers aren't done with Stage I, but who knows?
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62nalide (11-12-2019)
#11
I guess I'm going to have to measure the cc's now. I need to know what the compression ratio will be. Might as well do the runners too I guess.
#12
TECH Senior Member
I was calling it a stage 1 porting because the valves are still stock and the guy I bought them from called them stage 1. It seems to me that larger valves are usually a notable difference between a stage1 and stage 2 porting.
I guess I'm going to have to measure the cc's now. I need to know what the compression ratio will be. Might as well do the runners too I guess.
I guess I'm going to have to measure the cc's now. I need to know what the compression ratio will be. Might as well do the runners too I guess.
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cookseyb (11-13-2019)
#15
I have yet to contact Lloyd Elliot, I have measured the ports and combustion chambers though. Intake ports are 225cc, exhaust ports are 86cc and combustion chambers are 61.5cc. Since I can see that material has been removed from the combustion chambers these heads must have been milled to shrink the chambers.
Is the milling a negative? I have to crunch the numbers and see how the size of the combustion chambers changes my compression ratio but if that's ok is there any other disadvantages to the milling? PtV clearance perhaps?
Is the milling a negative? I have to crunch the numbers and see how the size of the combustion chambers changes my compression ratio but if that's ok is there any other disadvantages to the milling? PtV clearance perhaps?
#16
TECH Senior Member
Since 799/243 heads are normally 210 intake, 75 exhaust, and 65 chamber, these should be some nice heads!
If the chambers weren't opened much, they wouldn't be milled too much either.
Milling in itself isn't a minus. PTV would really only be a concern with a high duration, high overlap (low LSA) cam.
If the chambers weren't opened much, they wouldn't be milled too much either.
Milling in itself isn't a minus. PTV would really only be a concern with a high duration, high overlap (low LSA) cam.
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KW Baraka (12-05-2019)
#17
Did some number crunching on the CR. I'm building a sbe LS2. I was planning on running .041 thick head gaskets for better quench. Using .007 above deck I get 11.82 static and 9.04 dynamic with the BTR Stage 2 cam I was planning. Stock thickness gaskets net 11.49 & 8.79
Is this too high a CR for pump gas?
Is this too high a CR for pump gas?
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G Atsma (11-23-2019), Jay Fisher (11-24-2019)
#18
ModSquad
iTrader: (6)
Did some number crunching on the CR. I'm building a sbe LS2. I was planning on running .041 thick head gaskets for better quench. Using .007 above deck I get 11.82 static and 9.04 dynamic with the BTR Stage 2 cam I was planning. Stock thickness gaskets net 11.49 & 8.79
Is this too high a CR for pump gas?
Is this too high a CR for pump gas?
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jlangley (11-24-2019)
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jlangley (11-24-2019)
#20
TECH Senior Member
iTrader: (16)
Advanced Inductions does use OE valves on some of there stuff. If you look at these 2 threads with pictures we might be on to something. Perhaps contact them and see.
https://ls1tech.com/forums/parts-cla...243-heads.html
https://ls1tech.com/forums/parts-cla...6cc-heads.html
https://ls1tech.com/forums/parts-cla...243-heads.html
https://ls1tech.com/forums/parts-cla...6cc-heads.html
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jlangley (11-24-2019)