Amazing: Pisto to valve clearance

Dark_5.0 · 07-30-2006, 01:17 AM

Ed curtis at Flowtech Induction told me the .566 lift cam he sent me would clear with stock pistons but i didnt believe it.

.566 Intake 218 duration
.566 exhaust 224 duration

I had my Canfield heads worked over by Abbot racing heads( 5 angle valve job, blended bowls, unshrouded valves and set up my springs for this cam.) and was not to happy when they told me they surfaced 15 thousanths of the heads. I thought great no way the cam will clear now.

I had .104 clearance on the intake valve and .184 clearance on the exhaust valve. This is with 2.02 1.60 valves

I measured piston to valve clearance using self hardening clay and some solid lifters. I repeated the process several times to ensure accuracy.

I fired the car up tonight and all is well. I should be flirting with the 11's with the head work and custom cam.

Obviously duration has more to do with clearance than lift.

~The Jester~ · 07-30-2006, 07:19 AM

Valve clearance is in the realm of Black Magic, well a "dark science" at best. Oddly enough, your minimum clearance does NOT occur at top dead center. You're right, duration has alot to do with it, as does overlap and centerline.

Glad ya got it all worked out and the engine is happy happy! Let us know when you get that 11.80!

fiveohpatrol · 07-31-2006, 10:01 AM

if ed told you it will work, it will work

Dark_5.0 · 07-31-2006, 10:13 AM

Quote:

Originally Posted by fiveohpatrol

if ed told you it will work, it will work

I am a believer.

I made 301 RWHP and 330 RWTQ last time I went to the dyno with a ported cobra intake, out of the box Canfield heads and the good ol E cam. I cant wait to see what I put down with the Trickflow track heat intake manifold, worked over Canfield heads and a custom FTI cam.

I am hoping to put down 330HP and 330TQ.

fiveohpatrol · 07-31-2006, 10:16 AM

well if it doesn't make those numbers, don't get too disappointed, just look at the average power in the useable RPM range. A lot of people get hung up on peak numbers, whichs is ok, but the average gains are where it's really at. good luck

~The Jester~ · 08-01-2006, 03:27 PM

Quote:

Originally Posted by fiveohpatrol

well if it doesn't make those numbers, don't get too disappointed, just look at the average power in the useable RPM range. A lot of people get hung up on peak numbers, whichs is ok, but the average gains are where it's really at. good luck

Zackly! Peak horsepower at 15,000 RPM isn't very usable.

fiveohpatrol · 08-01-2006, 07:59 PM

Quote:

Originally Posted by ~The Jester~

Zackly! Peak horsepower at 15,000 RPM isn't very usable.

unless you're in a honda

07-30-2006, 01:17 AM	#1
Dark_5.0 Registered Member Join Date: Apr 2001 Location: Staging lane Posts: 4,337	Amazing: Pisto to valve clearance Ed curtis at Flowtech Induction told me the .566 lift cam he sent me would clear with stock pistons but i didnt believe it. .566 Intake 218 duration .566 exhaust 224 duration I had my Canfield heads worked over by Abbot racing heads( 5 angle valve job, blended bowls, unshrouded valves and set up my springs for this cam.) and was not to happy when they told me they surfaced 15 thousanths of the heads. I thought great no way the cam will clear now. I had .104 clearance on the intake valve and .184 clearance on the exhaust valve. This is with 2.02 1.60 valves I measured piston to valve clearance using self hardening clay and some solid lifters. I repeated the process several times to ensure accuracy. I fired the car up tonight and all is well. I should be flirting with the 11's with the head work and custom cam. Obviously duration has more to do with clearance than lift. __________________ 92' LX-Big brakes, Lots and lots of suspension, GT40X heads, Ported cobra intake, stock cam, Vortech SC trim. 00' Lightning-Stock 88'CRX-13 second ego killer

07-30-2006, 07:19 AM	#2
~The Jester~ Rat Killer Join Date: Aug 2002 Location: Cold ass Ohio Posts: 1,143	Re: Amazing: Pisto to valve clearance Valve clearance is in the realm of Black Magic, well a "dark science" at best. Oddly enough, your minimum clearance does NOT occur at top dead center. You're right, duration has alot to do with it, as does overlap and centerline. Glad ya got it all worked out and the engine is happy happy! Let us know when you get that 11.80! __________________ d-Con Racing "Nothing fancy, just 347 inches of RAT POISON!" MICE need not apply.....

07-31-2006, 10:01 AM	#3
fiveohpatrol I'd rather be basketweaving Join Date: Feb 2000 Location: Indianapolis Posts: 2,551	Re: Amazing: Pisto to valve clearance if ed told you it will work, it will work __________________ NMRA O/C 9516 NA pumpgas stickshift 347 10.65@125.6, 6.73@100, 1.41 60ft

07-31-2006, 10:16 AM	#5
fiveohpatrol I'd rather be basketweaving Join Date: Feb 2000 Location: Indianapolis Posts: 2,551	Re: Amazing: Pisto to valve clearance well if it doesn't make those numbers, don't get too disappointed, just look at the average power in the useable RPM range. A lot of people get hung up on peak numbers, whichs is ok, but the average gains are where it's really at. good luck __________________ NMRA O/C 9516 NA pumpgas stickshift 347 10.65@125.6, 6.73@100, 1.41 60ft

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