TU and F4 Camshaft Follow-on Discussion

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Originally Posted by 4 l-bodies

I would run something like the Comp Cams conicals around 1.700" which will put you around 130 something closed and around 280 lbs open. The conventional 942 Comp spring will fall close @ around 115 closed and 280 open at those same heights. There are other springs that will have close to those spring rates. Machinist might have problems getting to 1.7 something depending on valve choice (tip heights). Whatever he does don't have them sink valves to gain heights. You'll kill the flow of cylinder head. One thing to be careful of is to watch is retainer/keeper to valve guide/seal clearance with this much lift of camshaft. Also make sure you have .050 clearance at all valve lifts on all valves from top of retainer to followers.
Todd

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Comp springs are exactly what I’m running.
I’ll forward this information to him.
Thank you. 👍🏻


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Quote:

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Originally Posted by 4 l-bodies

I would run something like the Comp Cams conicals around 1.700" which will put you around 130 something closed and around 280 lbs open. The conventional 942 Comp spring will fall close @ around 115 closed and 280 open at those same heights. There are other springs that will have close to those spring rates. Machinist might have problems getting to 1.7 something depending on valve choice (tip heights). Whatever he does don't have them sink valves to gain heights. You'll kill the flow of cylinder head. One thing to be careful of is to watch is retainer/keeper to valve guide/seal clearance with this much lift of camshaft. Also make sure you have .050 clearance at all valve lifts on all valves from top of retainer to followers.
Todd

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FYI: I screenshot your response and sent it directly to my machinist in a txt.

Thanks man! 🤘🏻


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Originally Posted by 4 l-bodies

So does anyone have a Taft S3 they want #'s ran on? I'll do all the timing events for pro bono if someone wants to send one to me so we have data on that too. BTW- No damage to camshaft will take place. Engine is not run during this procedure.
LMK,
Todd

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Todd, what would you charge me if I sent you out a cam to get the data from? I ordered it from Colt as a custom grind, I gave Geoff the specs @.050 but im not sure after reading this entire post if he would have done it at the lobe or the valve.

Nick

Hey Nick,
Just saw this. I looks like I'm not getting notifications from T-M anymore (again), so sorry for the delay. At the moment, I have no 8V engines on stands (that aren't completed), or have 16V's, so not real easy for me to degree a 8V camshaft in at the moment. I would have to mock up a shortblock and head to be able to get some measurements for you. Won't happen real soon is what I'm trying to tell you.
Todd

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Originally Posted by 4 l-bodies

Hey Nick,
Just saw this. I looks like I'm not getting notifications from T-M anymore (again), so sorry for the delay. At the moment, I have no 8V engines on stands (that aren't completed), or have 16V's, so not real easy for me to degree a 8V camshaft in at the moment. I would have to mock up a shortblock and head to be able to get some measurements for you. Won't happen real soon is what I'm trying to tell you.
Todd

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Todd, please check your junk/spam folder and also what email address you have on file. I get a lot of bounced emails in the T-M admin email folder. Please let me know either way, trying to learn how to fix stuff around here.

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Originally Posted by 4 l-bodies

Hey Nick,
Just saw this. I looks like I'm not getting notifications from T-M anymore (again), so sorry for the delay. At the moment, I have no 8V engines on stands (that aren't completed), or have 16V's, so not real easy for me to degree a 8V camshaft in at the moment. I would have to mock up a shortblock and head to be able to get some measurements for you. Won't happen real soon is what I'm trying to tell you.
Todd

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So what would the difference in duration be at the valve versus the lobe? Say its a 224 lobe duration.


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Nick,
You should go back and read this thread. The answer to your question was talked about at length, by some pretty knowledgeable people on this forum. Read posts that have info on Cam-Pro, Cam Dr., translating vs. pivoting follower, follower ratio, etc. In a nutshell, there is no easy formula to convert a Cam-Pro printout to actual #'s taken at the valve, as the follower on the Cam-Pro is a translating type follower, and the 2.2 uses a pivoting type follower. Audie Technology Valve Pro program is said to be able to convert translating profiles to valve motion, but it is just common practice to measure valve motion in the engine for pivoting followers.
I wasted a bunch of money constantly running various stock and aftermarket cam profiles on Cam-Pro measuring stands. In the end they were not even close to actual measurements at the valve. It did provide me some data on comparing one camshaft to another camshaft though, but not actual in-car specs.
I did post results from several different camshafts in this thread. Hope you saw those. There were at least five that I remember posting, maybe more.
Todd

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Originally Posted by 4 l-bodies

Nick,
You should go back and read this thread. The answer to your question was talked about at length, by some pretty knowledgeable people on this forum. Read posts that have info on Cam-Pro, Cam Dr., translating vs. pivoting follower, follower ratio, etc. In a nutshell, there is no easy formula to convert a Cam-Pro printout to actual #'s taken at the valve, as the follower on the Cam-Pro is a translating type follower, and the 2.2 uses a pivoting type follower. Audie Technology Valve Pro program is said to be able to convert translating profiles to valve motion, but it is just common practice to measure valve motion in the engine for pivoting followers.
I wasted a bunch of money constantly running various stock and aftermarket cam profiles on Cam-Pro measuring stands. In the end they were not even close to actual measurements at the valve. It did provide my some data on comparing one camshaft to another camshaft though, but not actual in-car specs.
I did post results from several different camshafts in this thread. Hope you saw those. There were at least five that I remember posting, maybe more.
Todd

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Gotcha, so I've ran back through and read this post. So the duration doesnt actually change, but you'd measure .050 lobe duration at .0875 lift at the valve instead of .050.

My engine guy is going to run the cam on a cam dr. just to make sure its all good and the lobes for each cylinder are ground the same. He is going to give me a print off as well and I can post it. I went with a split duration instead of a reverse pattern.

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Originally Posted by Loudexploder

Gotcha, so I've ran back through and read this post. So the duration doesnt actually change, but you'd measure .050 lobe duration at .0875 lift at the valve instead of .050.

My engine guy is going to run the cam on a cam dr. just to make sure its all good and the lobes for each cylinder are ground the same. He is going to give me a print off as well and I can post it. I went with a split duration instead of a reverse pattern.

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Have your engine guy make sure he sets up the machine properly for your application. For starters, many V8 cams have the opposite lobe on the end. So make sure he knows the belt end lobe on the end is the exhaust (lol). Some machines assume setup for solid lifters, so they build in about .010 lash into the equation. Then others, the roller lifter they use are WAY off as far as diameter compared to Chrysler's .700" diameter follower. I have found many of Colt Cams camshafts (esp. the reground ones) to vary in base circle diameter a few thousands. Some even from intake to exhaust on the same cylinder. Like you said, the whole point of running it on a Cam Dr. is to check "stuff" like you do when indexing a crankshaft. Doesn't do you much good if all four cylinders events aren't taking place when they should be. Also make sure they set follower ratio on checker at 1.75-1.77. 1.77:1 is listed as the #, but almost all followers are closer to 1.75:1.
Look forward to seeing the posted results.
Todd

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Originally Posted by 4 l-bodies

Have your engine guy make sure he sets up the machine properly for your application. For starters, many V8 cams have the opposite lobe on the end. So make sure he knows the belt end lobe on the end is the exhaust (lol). Some machines assume setup for solid lifters, so they build in about .010 lash into the equation. Then others, the roller lifter they use are WAY off as far as diameter compared to Chrysler's .700" diameter follower. I have found many of Colt Cams camshafts (esp. the reground ones) to vary in base circle diameter a few thousands. Some even from intake to exhaust on the same cylinder. Like you said, the whole point of running it on a Cam Dr. is to check "stuff" like you do when indexing a crankshaft. Doesn't do you much good if all four cylinders events aren't taking place when they should be. Also make sure they set follower ratio on checker at 1.75-1.77. 1.77:1 is listed as the #, but almost all followers are closer to 1.75:1.
Look forward to seeing the posted results.
Todd

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Here are the results he gave me. https://uploads.tapatalk-cdn.com/202...714e161dd1.jpg


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https://uploads.tapatalk-cdn.com/202...200db311f9.jpg


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https://uploads.tapatalk-cdn.com/202...bf964fd2ae.jpg


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Here is the cam card from LRE that I told you about in PM. Was originally in Steve Calder's CSX then into boost geek's car.

Attachment 65731

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Originally Posted by 4 l-bodies

Here is the cam card from LRE that I told you about in PM. Was originally in Steve Calder's CSX then into boost geek's car.

Attachment 65731

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So that is 226 but measured at the valve correct?


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Quote:

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Originally Posted by Loudexploder

So that is 226 but measured at the valve correct?


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Yes at the valve. Your duration @.050 is much bigger. Better be checking clearances at piston, guide, seal, spring coil bind, and retainer. Doubtful it will be a non interference engine with that installed (lol).
Todd

I am ordering custom pistons from a chamber mold, springs are already on and everything is set up. We ended up using the PAC-1201 springs.


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