Did you check it at TDC ? Or at 10 deg. before and after TDC?

 

Did you just stack feeler gauges between the roller tip and the valve stem?

Did you check at multiple degrees before and after TDC during overlap?

 

Yes stacked feeler gauges between the tip of the valve and the tip of the rocker at top dead center

 

Checked at top dead center.

 

Make sure you check before and after tdc. It can get even closer. The pros will chime in here.

 

Do it again with zero lash and measure it 10 before, 5 before TDC, at TDC, 5 after, 10 after just to be sure. It may be time consuming but the assurance is worth it.

 

put clay on the piston,zero lash,turn it over and check the clay---u probibly have moe than you think.how your checking leaves too much room for error-imo

 

You need to check it before and after TDC on the exhaust/intake stroke.

 

Yep 10* before and after 10* tdc.

 

If you could make a decision based only on the information given would you say acceptable or not acceptable? Current compression ratio is 11.375 to 1 if I go with a thicker gasket I can go as high as .071 that would drop compression down to 10.5 to 1 that is also an option to increase piston the valve clearance. What say you about that option?

 

whats the quench?

Did you degree the cam?

Where is the cam in at?

 

Also set up a dial indicator on the retainer rather than stacking feeler gauges

 

Another piece of the puzzle is the engine is still in the car

 

I am going to say if you put clay on top of the piston put a head on an roll the engine over you will find you have a ton more then you have measured. With all the different cam types an grinds I am wondering who cam up with the wonder number of 10 before 10 after. An at 0 Why would the valves be open at tdc.

 

depending on where the cam is at, you could advance it and gain some exh. clearance

.068 will probably work fine if that in fact is your tightest spot and are certain on your measurements and valve train is in check

 

I like the clay some do some dont

 

You can't check it at tdc, you need to check the intake 8-10 deg after tdc and the exhaust 8-10 deg before tdc. Set the lash to what ever you will run it at.

 

To add a little more info to Al's post the engine is assembled and in his S10 truck . It ran some high 10's at PRP this summer with a set of Dart Platinum heads and a cam in the 600 lift neighborhood. He purchased a set of AFR heads so my son removed the Dart heads and we installed the AFR's with a light set of testing springs on #1 cylinder, set our valves at .014 and installed our feeler gauges and I gently turned the engine over by hand. The feeler gauges were in during the entire cycle. This is how we came up with the above numbers.

 

To add a little more info to Al's post the engine is assembled and in his S10 truck . It ran some high 10's at PRP this summer with a set of Dart Platinum heads and a cam in the 600 lift neighborhood. He purchased a set of AFR heads so my son removed the Dart heads and we installed the AFR's with a light set of testing springs on #1 cylinder, set our valves at .014 and installed our feeler gauges and I gently turned the engine over by hand. The feeler gauges were in during the entire cycle. This is how we came up with the above numbers.

Take the feeler gauges out and check it with the proper lash, intake 8-10 deg. after tdc, exh 8-10 deg before tdc.

 

you let the piston run into the valves??

 

dont forget the radial clearance too. I usually check @ 5,10,15 degrees before and after.

 

i like the clay to check clearance ,ive ran mine as tight as .065 but im on top of the valve train and springs ,id rec .100 on both

 

ADN406,

please post the two diget cam timing numbers as measured at .050" lifter lift....

what the timing card SAYS

along with what the nnumbers THAT WERE ACTUALLY GOT...

 

When you put the loaded valve train together the piston to valve clearance will pickup from .020 to .070 over what checking springs show.We have seen lash,bend and flex open up the piston to valve clearance as much as .070 on a 1200#spring with 1/2 in pushrods and 1.085 gross lift.Bill C.

 

True! I mocked up my new heads with checker springs and I was down to .030 on the exhaust. I thought i was in the shit. Tried it with the actual springs and I had .090 on the exhaust. Have had the heads off to fix a small problem since, no kissing or cuddling between valve and piston

 

I ran .035/.045 in my last motor up to 7200 regularly, street car. Measured with checking springs and with clay

 

I think the exhaust is too close. The closest I've ran is .086. On the intake you can get as close as .040 without problem. Move the cam, and extend the clearance on the exhaust, and close up the intake. Just my thoughts.

 

X2.......... better be safe then sorry........

 

Use clay and the proper valve springs and lash etc. roll the motor over by hand--you will probably have over .090 on the exhaust when you do it this way--cut the clay with a razor blade after doing this and measure the thickness of the clay on the valve relief area--you will probably be fine with the setup you have especially if you are using a slightly thicker gasket than the used one used to check it with---just my opinion--has always worked for me

 

I think what everyone here is trying to tell you is that the piston is closer to the valves during rotation near TDC, but not at TDC. Should be checked 5 + 10 degrees before and after TDC on both exhaust and intake to be safe. I don't remember where they are the closest, but its not TDC.

 

.082 On the exhaust with clay measurement and real springs. Run it?