I am putting about $6,000 worth of parts (no labor) into this build....I guess that is really nothing to worry about...

Besides the money I want to know that everything is correct.

 

Cutting pistons has not been considered for this build yet.


I cut MINE (a different car) with a 240/244-111 cam and 59cc heads with .040" gaskets...it wasn't an option, it was an absolute requirement.


But thanks for the similar comparison.
I'm very curious to see the same clearance checks done with his stock LS6 heads.

 

If the ramp was slower, it would definitely help, if you noted where the tightest point of clearance is.
The valve is opening, coming off the seat, and accelerating towards the piston. A steeper ramp lobe would make this situation worse, not better.

Plus, I'm not sure there are any steeper ramp hydraulic lobes than the XE-R. If I'm not mistaken, even the newer high lift lobe designs are not quite as steep in the profile near the opening and closing events.

 

Are the rockers "accelerated lift"?

 

Rockers are Jesel Sprortsman Series 1.7/1.7 ratio. They are part # KSS-307070. Haven't seen them advertised as accelerated lift.

Talked with Comp Cams & TEA this morning. Comp says my cam is a 113 with 3 degrees ground in and should be installed on 110 centerline.

TEA did a quick calc and thought I should see .076 clearance at TDC. This will change slightly at 10 deg ATDC, so I guess I need to verify the measurement one more time to be sure. I will use an adjustable pushrod this time and make sure it is zero lash. Mike at TEA was concerned that when I bolt down the rocker it could preload the lifter .040 and in effect take away that PTV clearance.

If this checks out again at .040 PTV I have 2 options. I can retard the cam a couple of degrees which may not get me where I want. Personally I am not excited about this option. The other option is to fly cut intake valve reliefs in my pistons. Mike was generous enough to offer shipping me a bare head for this purpose. Not excited about that option really either but given the two....I may bite the bullet and notch .060 valve relief if needed!

 

You have one other lousy option, smaller/different cam. Not a fun situation to be in, hope it all works out.

 

So to make a solid lifter out of one of my old stockers I remove the spring, and the plunger piece just underneath it. Then I fill the gap up to the spring with 3/16 washers? I may make two of these this afternoon if I can get the details!

 

Pretty much. I have some photo's at home of them apart and how I did it. If you plan to use the lifters afterwards, it may not be the best plan to do this. If they are being replaced (as I remember you have Morels waiting to go in) then it would be OK. Note also, Morels are taller and use less preload (later when measuring for pushrod length).

 

I know how much the parts cost, I practically have the same stuff. Unless the Jesel rockers have an impact on valve clearances, versus the Harland Sharps I used, I still firmly believe you have plenty of clearance with that cam. It's your time/money/stress, so do whatever makes you feel good.

 

Appreciate your input. I am just the type that doesn't want to have to worry or question what is being done. I know that I could run the setup as is....but the clearance we measured, (if confirmed again using solid lifter and adjustable pushrod) is too tight. All it takes is some float or a missed shift and problems could occur. Maybe that would not ever happen but I will sleep better knowing for sure.
This will be a small delay in getting the project complete - especially if fly cutting is needed, but well worth it in the end!

 

In light of this offer....Let's do it!

As you know, I had a friend run your specs through some engine building software last night....with the GM gasket, he calculated the intake p/v tight spot at .058" @ 8* ATDC. Since he computed this with 2.02" valves, and you just informed me you have 2.04", the larger valve would further reduce clearance and probably put his calculated pretty damn close to what we're seeing.

TEA's calculated .076" at TDC is also pretty close to what we are getting for readings.


At this point, I'd strongly urge you to take Mike up on his offer, and get that bare head in the mail. Lucky for you...you know someone with a 2 1/8" cutter and a bit of experience doing this.

 

In all seriousness, I could have all 8 of your pistons cut in a few hours. It is not a big deal at all, and the peace of mind knowing you'll have adequate clearance is priceless.

 

Tom,

I will call Mike and get it shipped out. I had kind of already made up my mind this would need to be done. Even if we were off by some lifter preload, it is not as much clearance as I would like based upon our measurements. I already ordered a custom cutting tool and correct stem for my valve from Lindy. Wasn't too bad at $78 + $28 and they will try and have them to me before the weekend if possible. So thanks for the offer on the tools anyway! Your experience doing this will be invaluable though....so I will take you up on that!

 

So what are your measured p/v clearances?

Successfully spinning it to 6900 is not a measurement...so if you don't even know exactly what clearances you have, how the hell can you advise others what clearances they should have?

Now that our actual measured clearances have been more/less validated by two other credible sources...perhaps YOU should be the one worrying about the future day when a spring goes soft and starts to float. Especially with those HS rockers. (don't forget to post pics of the carnage).

In a way, this is good news for us. We found the "no problem" long before it had a chance to became a very serious problem, and with that knowledge, we can continue building the reliable engine the OP is wanting.

He could have just stuck the cam in dot to dot and spun it to 6900 too. And probably not had a problem....But I think he's now very thankful we chose to measure it and can make the necessary corrections and insure it will never be a problem.

 

Kurt, really curious to know the numbers that were calculated on your new setup. I am not an expert but yours appears like it would have less clearance than mine. We are going to have to flycut the intake valve reliefs into my pistons.

 

Verne,

Don't remember if you guys ever measured exhaust clearance. If not, you may want to get those numbers before the tools arrive "just in case". Take some good photo's when you do this

 

Exhaust didn't seem to be all that close (by feel)...if it was anything as alarmingly close as the intake was, we would have put the indicator on it too. (we eventually will anyways just for documentation purposes)...but I think he's fine on that side, well over .100" even at it's closest point.


I do have a cutter for the exhaust valve too if the need arises.

 

I may get a chance to put a dial indicator on the exhaust side tomorrow sometime. We will see how it goes as I have a few other things I need to do also! But, like Tom says I don't expect a problem from what we saw on Saturday.
As you know I will take plenty of pictures!

 

OK. I just go by my experience, if it can turn to crap it turns into crap squared in a hurry

 

I would think it was obvious that I didnt' go to the lengths of anality (is that a word?) to do procedures like claying/degreeing that some people seem to regard as essential. I read up on the procedures for months over a LS1tech, from dozens of others, and concluded that I had plenty of safety margin with my cam to forego those steps. My cam is a Crane 228/232@112+5-.600/.600, so it's marginally smaller than the OP's. I discussed my setup with the guys at TEA, as well as LS1tech, and they all agreed I'd have no problems. If you and your buddies need to check everything, more power to ya, but I trust those who have a great deal more experience than I do. Doing things your own way is an American tradition, and since the OP was experiencing some angst, I thought my opinion might offer some reassurance.