New heads + 1.6rr's = more piston valve clearance?

[95CobraMike]

I just got some new windsor sr lite heads with 2.02 and 1.60 valves 64cc combustion chambers... my rockers are ped mount 1.6's... pistons are speed pro forged (slightly dished to keep the comp ratio down) the pistons look like they have pretty much stock valve reliefs in them....Cam specs are .493/.513lift, 212/[email protected], 112 lsa

anyway i was wondering if by going with these heads and 1.6's if i would be able to run a slightly bigger cam?

with my iron gt-40s and 1.7's i ran the wolverine 1190 without problems...

thinking about going up to the wolverine 1087 222/232 @ .050", 112 LCA, 510/534 lift

 

[Joes95GT]

It's the valve that's the problem, not the cam.

It's VERY tough getting a 2.02 valve to clear with any cam, even the stocker. It depends on free drop of the head, how far the piston is in the hole, and the intake valve opening and exhaust valve closing point.

Joe

 

[95CobraMike]

dont alot of aftermarket heads have 2.02 intake valves? how do those people do it?

 

[wytstang]

Jay Allen sometimeshangs out on Corral send him a pm. I would love to see what the 1087 could do on a blown motor
http://www.corral.net/forums/showthread.php?t=716108

 

[95CobraMike]

i would love to see it too.... but i dont really want to have to buy the cam install it and find out it wont work...

How do people run lift like over .550 and crazy duration with aftermarket heads???

 

[Joes95GT]

dont alot of aftermarket heads have 2.02 intake valves? how do those people do it?

They aren't doing it with a stock shortblock. AFR's wont work, and neither will Edelbrock's 2.02 heads.

As I said before, it depends on free drop of the heads, and in some cases, valve angle when using 2.02 valves on the stock shortblock.

And, you're forgetting, lift doesn't mean **** when talking about a camshaft clearing pistons. At max lift, the piston is down at the bottom of the bore, no where close to the valve.

Joe

 

[95CobraMike]

what is it that people are changing about their shortblocks that is allowing them to use 2.02 valves?

What is free drop?

 

[final5-0]

what is it that people are changing about their shortblocks that is allowing them to use 2.02 valves?

What is free drop?

Not sure about free drop

but

After market pistons usually have deeper reliefs in them.

Seems like I have seen some say that with 2.02's, the larger size valve will touch on the side of the relief anyway.

Grady

 

[Joes95GT]

It's all a craps shoot with aftermarket pistons unless you know that those pistons are designed to work with your SPECIFIC cylinder head and valve set-up.

As far as free drop - free drop basically means how much room the valve has in the combustion chamber. Given a fixed size, say 64cc combustion chamber, it can have an infinite number of shapes. It can be very wide and shallow to achieve the 64cc or it can be narrow and deep to get to the same size. The narrow and deep combustion chamber would allow for more "free drop" because of it's upside-down box shape.

I hope that makes sense....

Joe

 

[RIO5.0]

It's all a craps shoot with aftermarket pistons unless you know that those pistons are designed to work with your SPECIFIC cylinder head and valve set-up.

As far as free drop - free drop basically means how much room the valve has in the combustion chamber. Given a fixed size, say 64cc combustion chamber, it can have an infinite number of shapes. It can be very wide and shallow to achieve the 64cc or it can be narrow and deep to get to the same size. The narrow and deep combustion chamber would allow for more "free drop" because of it's upside-down box shape.

I hope that makes sense....

Joe

Ya, what he said....

Damn I didn't understand chit on that one...way over my head...I'm impressed though.....

 

[zkillrr]

I"m impressed also, my ? is are the gt40s up for sale now!

 

[95CobraMike]

ok i understand free drop...
when i called to order the pistons from jegs, i told them what heads i had, what cam and the specs, and what comp ratio i wanted.... the guy told me that the should work.......

i actually sold my gt-40's on ebay i think they went for $460

 

[Stang D]

ok i understand free drop...
when i called to order the pistons from jegs, i told them what heads i had, what cam and the specs, and what comp ratio i wanted.... the guy told me that the should work.......

You intended to use some clay and measure them anyway right? In the event you make yourself some canted valve 2.02 heads, "the guy" will turn on you like a pet wolverine. Especially when you are telling his boss you'd like some free heads. First he'll get amnesia. Next he'll tell you any dummy knows you gotta do pre-assembly checks on any high perf engine.

WAAAY too much money in that nice engine or yours to leave it to chance.

 

[95CobraMike]

yes i plan on checking the clearances... i kinda have to

 

[Methodical]

They aren't doing it with a stock shortblock. AFR's wont work, and neither will Edelbrock's 2.02 heads.

As I said before, it depends on free drop of the heads, and in some cases, valve angle when using 2.02 valves on the stock shortblock.

And, you're forgetting, lift doesn't mean **** when talking about a camshaft clearing pistons. At max lift, the piston is down at the bottom of the bore, no where close to the valve.

Joe

Duration

 

[95CobraMike]

i dont think i have all that much duration....
im only at 212 intake and 222 exhaust @.050

 

[dstanggt50]

I would think with a 2.02 valve, your gonna need some valve reliefs, I have the windsor jr's w/the 1.90 valve, and I wanted to step up from a 1.6 to a 1.7 rocker when I was having the shortblock built, and they said I wouldn't be able to run them w/out clearance issues. I don't think the 2.02 will work unless its like a tfs head ( I've heard they can run cams w/the 2.02 valve)

 

[95CobraMike]

what are the diffrence between the jr's and sr's? other than valves i mean... i am running 1.6's also