TXsilverado

iTrader: (18)

stock bottom LS2 with TFS 225 heads. stock LS2 gaskets.

the cam is a 236/242 .612/.612 110+4

here are the full specs on the cam. PN 190265-10

http://www.howardscams.com/chevrolet...l-1997-present

would you expect this cam to clear on this combo?

-Joseph-

iTrader: (12)

I always suggest checking, I have seen similar camshafts clear on stock heads, but it was tight. I believe the TFS heads in unmilled form have an extra bit of clearance due to the different valve angle, so that also is a plus to helping out in the cam fitment department.

TXsilverado

iTrader: (18)

****. yeah the heads have been milled .030.

Sales@Tick

iTrader: (3)

If the heads have been milled I wouldn't feel safe without measuring.

TXsilverado

iTrader: (18)

i measured. exhaust clears on the tight side and the intake is stuffed into the piston at 5* atdc. although the engine turns over fine, but there's virtually zero clearance on the dial indicator. who rents some flycutting tools?

Sales@Tick

iTrader: (3)

Yea that 110lsa and 106icl is going to do that to the intake side.

TXsilverado

iTrader: (18)

quick question. i'm new to playing with degree wheels and looking at cam events.

should my intake valve start opening as soon as 46* BTDC?


im basically measuring by having my dial indicator on top of the pushrod while on the base circle and rotating the engine clockwise until i see that dial indicator move. i always thought that the intake valve doesnt open until the piston passes TDC.

TXsilverado

iTrader: (18)

lol and yes i just noticed i marked 41 BTDC instead of 46. in hurry to post while at work lol

Sales@Tick

iTrader: (3)

IVO is 37.5 °
IVC is 69.5 °
EVO is 81.5 °
EVC is 33.5 °

TXsilverado

iTrader: (18)

are those measurents at .050 off of base circle?

jmgak47

iTrader: (3)

No that is using the advertised duration at .006

Your going to want a minimum clearance .040 and even then your not safe if there is any slack in your timing set. Should be safe at .060 but you really wanna see .080

Take the advance out of the cam and check... fly cutting the pistons is going to be your best solution.

Sales@Tick

iTrader: (3)

Yep, advertised numbers.

ws6fitz

I have a buddy with just about the same combo. his heads are milled to 62.5CC and he has no problems. With taking them down .030 I forget what CC that makes it. But i know what he has is about the max you can go and not have PTV issues.

TXsilverado

iTrader: (18)

i measured and came up with .097 on intake and zero clearance on the intake side. the motor turns fine but the dial indicator shows zero from 3-108 ATDC. time to cut!

Sales2@Texas-speed

iTrader: (5)

If you have an adjustable set, you could try advancing the cam to give some of that intake clearance to the exhaust side (so to speak).

TXsilverado

iTrader: (18)

wouldnt that just make the exhaust tighter? the cutting tool is already on the way.

Sales@Tick

iTrader: (3)

No he is correct. Advancing the cam will make the exhaust valve open and close sooner. Closing it sooner will gain exhaust valve clearance as the EVC event will occur sooner before the piston reaches TDC.