guys with milled 243s...
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From: San Antonio, TX
guys with milled 243s... What cam do you have and did it require fly cutting? I have ported ones that are 62cc now and the btr stage 2 n/a cam but I'm thinking of going bigger with the cam. I'm on stock MLS head gaskets also. So I'm just curious what similar set ups are out there. I know I know... I will measure it to verify if I go bigger but I want to see what other people have used.
I am running 61.5cc TEA 243's with a .045 cometic gasket. Was told that 230 is about tops on intake duration with this setup, but my cam comes in around 227/231 112 with 1.85 ratio rockers.
Imo you are better off running a slightly smaller cam with more compression and tighter quench then going bigger on cam and less compression due to not wanting to fly cut and running a thicker gasket.
Imo you are better off running a slightly smaller cam with more compression and tighter quench then going bigger on cam and less compression due to not wanting to fly cut and running a thicker gasket.
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From: San Antonio, TX
I was at TSP yesterday and was told they sink their valves in for more clearance. he also said that since my heads probably didnt have the valves sunken in some, the biggest i could do from their line up is the 233/239. I agree with you kinglt1... a more efficient set up will out perform a non efficient giant cam one... my car as it sits is proof of that. Ive out ran several cars with bigger cams than mine. partial reason why I want a different cam is because I want it to sound more aggressive but I also think mine sounds a bit tamed down because it idles at 900 and the tune is somewhat conservative. anyway, thanks for sharing you guys
I have the similar set up as you. Stock 243s milled .035 around 58cc , the stock gm mls head gaskets and a BTR stage 2 N/A cam. I was pretty close on the ptv measurements, around .088 on the intake and i want to say .093 on the exhaust, so youre not going to be able to go much bigger without flycutting. I say run the cam, I havent had mine tuned yet, but it feels like it is going to make a real nice torque curve.
Thread Starter
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From: San Antonio, TX
I have the similar set up as you. Stock 243s milled .035 around 58cc , the stock gm mls head gaskets and a BTR stage 2 N/A cam. I was pretty close on the ptv measurements, around .088 on the intake and i want to say .093 on the exhaust, so youre not going to be able to go much bigger without flycutting. I say run the cam, I havent had mine tuned yet, but it feels like it is going to make a real nice torque curve.
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I have a 226/234 .612/.595 112+2 with 243 heads that have been milled 0.010" to a 63cc chamber with a valve job and my ptv was .090" for the intake and .100" for the exhaust. This was with the GM MLS gasket. Duration and advance with a camshaft can affect clearance quite a bit. Out of the hole measurement of pistons can affect things as well. Not all engines, even factory assembled, have that same measurement.
239/247 113+3 solid roller and my 799s are milled .015" using a stock ls2 head gasket
once warm the cam does behave like a 234/242 113+3 so it has more clearance at times it will be turning RPM
also worth noting the heads had a valve job so they are a little more sunk in the head which should reduce valve drop
once warm the cam does behave like a 234/242 113+3 so it has more clearance at times it will be turning RPM
also worth noting the heads had a valve job so they are a little more sunk in the head which should reduce valve drop
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From: Iowa
Hey mgood613,
I have the GMPP ASA cam, so its on lazier lobes than the howards, but same otherwise (obviously). I'm thinking of milling my stock 243s .007 for a clean up, then running a .040 or .045 cometic. What was your clearances on the intake and exhaust? I really don't want to flycut, and I'm not too sure how far my piston pops up. It's going to be a fee months before the car is out of storage, but I'm trying to research and accumulate my parts. I haven't been able to find any threads with people having PtV problems with the ASA.
I have the GMPP ASA cam, so its on lazier lobes than the howards, but same otherwise (obviously). I'm thinking of milling my stock 243s .007 for a clean up, then running a .040 or .045 cometic. What was your clearances on the intake and exhaust? I really don't want to flycut, and I'm not too sure how far my piston pops up. It's going to be a fee months before the car is out of storage, but I'm trying to research and accumulate my parts. I haven't been able to find any threads with people having PtV problems with the ASA.
On The Tree
Joined: May 2014
Posts: 169
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From: Iowa
That's pretty tight on the exhaust. Good to know tho. Is there any truth to the claim that TSP sinks their valves for more clearance? I would think that having my 243s milled only .007 would give me the extra .023 that I need for clearance, using your setup as a reference.
