bsf

iTrader: (7)

Engine Specs

• Stock bottom end
• 224/228 nominal XER lobe cam (225.5/229.8 .579”/.587” 110.5) advanced ~2 degrees on install with a Cloyes adjustable timing set. Did not degree because I have no degreeing kit compatible with LS engines.
• New LS7 lifters
• Cometic 0.045” gaskets
• Patriot Performance LS6 heads with stock (non-sodium filled 2.00”/1.55”) valves; un-milled (~64cc)
• 7.35” pushrods
• Stock rocker arms

PTV Check

• Clay method
• Done on cylinder 2
• Checker lifters (epoxied the removed original LS1 lifters)
• PTV clearance intake: -0.??
• PTV clearance exhaust: ~0

This is very surprising, and definitely does not please me. On cylinder 2 the intake valve touches the piston and the clay under the exhaust valve is so thin as to be transparent and immeasurable at the thinnest.

I have some questions.

Is it possible I did something wrong?

I am very surprised at PTVC. I mean, who with a 224/228 cam and unmilled LS6 heads has had to mill? Is my PTVC the result of the combination of me choosing a tighter LSA, the cam being ground larger that requested, and my Patriot heads? Some claim that the valve pocket in the chamber is not as deep on Patriot LS6 heads as others.

I am under the impression retarding the cam would help on the intake valve but further hurt clearance with the exhaust valve. Is that correct?

I noticed during the PTV check that the cylinder 2 valve springs stayed slightly compressed (~3/32”) while the lifters were on the base circle. Is this to be expected because the epoxied lifters are not compressing like unmodified hydraulic lifters would? This is not an indication my pushrods are too long, is it?

I do not want to make any decisions until I get advice from you guys. Tell me what you think?

-Joseph-

iTrader: (12)

Your valves need to be closed on base circle or you are not at 0 lash. You have to be at 0 lash to get anywhere near an accurate measurement when lift is present, thats why you are using solid lifters in the first place to not have false readings from preload (opposite of lash).

You have just about everything right except you need an adjustable pushrod or pushrod length checker to adjust that preload you have into 0 lash.

bsf

iTrader: (7)

Ok. That is why I asked. I was only born with 95% of all the knowledge in the universe. I am still trying to learn that last 5%.

I appreciate the response. I have a Comp Cams pushrod length checker, as that is what I used to determine pushrod length. Can that thing handle the force of the regular springs and compressing the clay, or do I need to install checker springs?

One additional question to improve my knowledge of engine mechanics. During operation, how much should a hydraulic lifter compress when it is on the cam base circle and when it is on the cam lobe? I assumed that it compressed the approximate amount of the preload.

-Joseph-

iTrader: (12)

I use checker springs myself. On preload, I like to see between .040" and .070" at the lifter when on the base circle. When its on the cam lobe with full spring pressure it will bottom out the lifter plunger. I've never actually measured, but I've been told that lift can be diminished by up to .020" when running on a hyd. lifter.

PREDATOR-Z

Something is not right on your install of the cam and advance.

What are the LSA and ICL of the cam?

That cam should clear with no issues.

SLED28

iTrader: (7)

Maybe your off a tooth also?

bsf

iTrader: (7)

LSA according to Cam Pro Plus report is 110.5. I advanced the cam ~2 degrees with the Cloyes Hex-a-Just timing set. I had planned on degreeing the cam, but the kit I borrowed has a degree wheel that will not work. It has only a tiny hole in the center.

I know it needs to be actually degreed. I am just sick of spending money on this project and was going to make a push to finish up. So, I am debating as to whether I should pay ~ $30 + SH to purchase a correct degree wheel or buy the Comp Cams degree kit for $134 + SH.

Also, anyone have any suggestions for an on-engine valve spring compressor tool kit? I borrowed a valve spring removal tool, but it is the type to be used when the head is off the engine. This installing and pulling and installing and pulling the heads is getting old.

Possible. I was quite conscientious about installing the cam Cloyes Hex-a-just crank gear correctly. It has 3 keyways (-4, 0, & +4 degrees). Also, I was careful to install the crank and cam gears “dot-to-dot”. As far as advancing the cam 2 degrees with the cam gear Hex-a-just bushing, I cannot be off more than 1 degree. I plan on degreeing now, so we shall see.

SLED28

iTrader: (7)

The hex adjust is very touchy, you may think its 1 degree, but could be 3 or 4. But 3 or 4 degrees wont do that, sounds like your off a tooth which is 14 or 16 degrees and could cause your problems. I hope you dont turn the motor over if the valves are touching the pistons, you could tweak them. Keep us posted!

PREDATOR-Z

You say LSA 110.5 but how about ICL
Does the cam have any advance ground in? If it is +4 and you advance again with the thinner gasket it might be close. Also TSP does a cleanup mill on the heads .003>.005 so there could already be that much loss in PTV.

Install dot to dot without advance and measure PTV. That will give you a clearer picture of what you're up against.

bsf

iTrader: (7)

The crank dot may be hidden behind the oil pump driver now, but I will double check.

I think I turned it over 3 times when doing the PTVC on cylinder 2. It took a couple tries. The first time I did not oil the valve faces good enough and the clay stuck and pulled apart. There was a little resistance at TDC, but nothing that concerned me at the time. I thought it was just the clay. I really hope everything is ok.


Sorry, was tired. According to Cam Pro Plus report, at .05” lift, ICL is 111.2 and ECL is 110.9. So actually, it was ground retarded, double entendre intended. TSP never touched my heads, they are Patriot Performance.

I have not worked on it since I did the second PTVC check. I am going to make something to eat first. Then I will adjust the Hex-a-just bushing back to 0 degrees (w/ no load on cam) and double check the crank/cam gear alignment. Assuming they are good, I can try claying again and get back with you guys. Thanks for the help.

bsf

iTrader: (7)

Ok. Confirmed that the crank and cam gears were installed dot-to-dot. Set the advance back to zero using the Hex-a-just bushing. It was actually setting at ~3 degrees advanced based on the degree dots on the cam gear. Placed checker springs on cylinder 2. Set zero lash with an adjustable pushrod. Measure the clay using calipers.

Intake: 0.130”
Exhaust: 0.120”

That is much better.

I am going to advance the cam until the intake PTVC drops to 0.100”. Based on my calculations, I need to advance the cam to offset my cam grind being off; i.e. bump the DCR up.

Thanks for the help PREDATOR-Z, ~Joseph, and SLED28.

SLED28

iTrader: (7)

N/P, thats what we're here for.

bsf

iTrader: (7)

Advanced the cam to the 2 degree mark on the Hex-a-just cam. Re-checked PTVC.

Intake: ~0.100”
Exhaust: ~0.120”

Think I will take a little break to enjoy this little victory, and then get back to work. Boy, last night I was worried. Feel much better now.

-Joseph-

iTrader: (12)

N/P on the help, I had done that same thing quite a few years ago and threw off all my numbers from what I expected.

Thats about the amount of PtoV that I would have expected with that camshaft.

PREDATOR-Z

That looks good, congrats. Sometimes it is good to go back to baseline and start over.
Enjoy once tuned

wannafbody

iTrader: (2)

Dumb question...why is that Cam Motion cam so coppery colored? Is that a special coating of some type?

8.Lug

Summitracing

Seeing replies from Joseph Potak and Predator Z is pretty cool though lol.

wannafbody

iTrader: (2)

Not intentionally. Somehow I posted that question in the wrong thread.

G Atsma

Gotta agree with that!