Cam install - help!
04-12-2009, 09:34 PM
#21
Melting Slicks
Thread Starter
I hate to say this, but it seems you're making it way more complicated than is needed. My older TFS heads require a 7.9" PR, and the newer ones use a 7.5" IIRC. I'm not ****, but cautious, and as per instructions over @ LS1tech, from lots of guys that've done this, I just installed the cam dot-to-dot. No problems after many times @ 6900. I believe you're just worrying about nothing.
Besides the money I want to know that everything is correct.
04-12-2009, 09:37 PM
#22
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St. Jude Donor '03
I'm not surprised you have to cut the pistons?Just did a close setup with 60cc TFS,stock gasket and a higher lift 230/236 on 113 +2 and it had about .090 which is borderline.So a slower ramp 232 installed on a 110 would definitely get the intake reliefs cut.
On a side note we have run as close as .040 on the intake valves before but the springs can not float.
On a side note we have run as close as .040 on the intake valves before but the springs can not float.
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.
04-13-2009, 06:42 AM
#23
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St. Jude Donor '03
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.
04-13-2009, 11:34 AM
#25
Melting Slicks
Thread Starter
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!
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!
04-13-2009, 01:29 PM
#27
Melting Slicks
Thread Starter
Using a hydraulic lifter and a standard pushrod may be the problem. If you don't have a solid lifter, then use the adjustable and set to zero and re-measure. Just gently lift the rocker at the pushrod side each time to make sure the plunger isn't depressing and skewing the measurement.
04-13-2009, 02:26 PM
#28
Team Owner
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).
04-13-2009, 02:28 PM
#29
Race Director
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.
04-13-2009, 02:34 PM
#30
Melting Slicks
Thread Starter
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.
This will be a small delay in getting the project complete - especially if fly cutting is needed, but well worth it in the end!
04-13-2009, 02:35 PM
#31
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St. Jude Donor '03
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.
04-13-2009, 02:41 PM
#32
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St. Jude Donor '03
04-13-2009, 02:45 PM
#33
Melting Slicks
Thread Starter
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.
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.
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!
04-13-2009, 03:50 PM
#34
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St. Jude Donor '03
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.
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.
04-13-2009, 05:39 PM
#35
Melting Slicks
Thread Starter
your heads will have a number stamped on them...i gave my number to TEA and they pulled my work order...indeed they were 61cc .015-.018 mill
try and get a solid lifter in there....and/or cc the head your self
i didnt check mine...i only calculated it via head specs (intake and exhaust valve drop)
piston out of the hole, gasket thickness and cam lift.
PatG and myself calculated this, also calculated with Geoff at engine power systems (geoff cofounder of thunder racing), as well as gave the spec to TEA to confirm PTV clearance...got me worried now
try and get a solid lifter in there....and/or cc the head your self
i didnt check mine...i only calculated it via head specs (intake and exhaust valve drop)
piston out of the hole, gasket thickness and cam lift.
PatG and myself calculated this, also calculated with Geoff at engine power systems (geoff cofounder of thunder racing), as well as gave the spec to TEA to confirm PTV clearance...got me worried now
04-13-2009, 06:18 PM
#36
Team Owner
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
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
04-13-2009, 06:29 PM
#37
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St. Jude Donor '03
I do have a cutter for the exhaust valve too if the need arises.
04-13-2009, 06:35 PM
#38
Melting Slicks
Thread Starter
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!
As you know I will take plenty of pictures!
04-13-2009, 06:59 PM
#40
Race Director
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.
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.
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.