Hemi duration check

[Chipg56]

I do not know if they do that to achieve the numbers on a stock cam but they certainly do that to modify their own cams. The cost is $5.00 per mod. For instance if you want to modify the opening and closing on both lobes the cost is $20.00. To me, it is very much worth it rather then using some device to twist cams. To do this requires fastidious attention to detail when measuring what you need. Details which cannot be accomplished using junk tools.............I just re-read your post and see you are already using a Dyno cam. It should be easy to modify the cam grind to give you what you want. In my experience they will easily give you accuracy to 1/10th degree. Of course you need to be able to measure accurately to at least 1/10 degree to take advantage. You might find this interesting: https://4cycle.com/karting/threads/my-degree-wheels-are-junk-chances-are-so-are-yours.128979/

 

[bullerman]

You best take a seat when you call Dyno for a price to do just (1) cam. Set up time is lengthy. It isn’t worth their time to do just one cam.

Was just wondering. One of my friends had them grind a cam to his specs. I don't know what they charged him. I figure engine builders have a huge selection of cranks and they can twist the cam if need be.
I figure most people just put the cam in set the valves and go. I figure we are losing power also.

 

[Petty Race Engines]

Twist the gear on the crankshaft to achieve the desired centerlines, Rix also makes a tool for this as well

 

[bullerman]

I would be afraid to try it. I am sure I would mess it up.

 

[Petty Race Engines]

Worst case it’s a $35 crank… the gear is a press fit and can be moved multiple times without failure, 2024 AKRA rules allow tack welding but that not relevant in your case. I think Jody also did some videos on turning the gear, you’re on the right track watching them, good info

 

[bullerman]

Checked my cam today with the equipment I have. I have a 8" degree wheel and used my homeade indicator bracket. Center line on the intake on the cam card is 114.0. I show 112.5. I could be off with my degree wheel I am using. The cam rules we use says 222 degrees at .50 thousandths lift. I show 221. It says at .200 thousandths 88 degrees. I show 85.
On these cheater cams they sell they say the lift is right but the duration is off. I assume it's off on the .50 and .200 on the intake and exhaust. Will it be way off from a stock legal cam?
We have a track here with new owners. I am hoping the tech man really checks some motors this year. I doubt if there was one lift or duration check done last year. I know it takes a little time but I believe as racers we deserve it. We have one track that doesn't even have a tech man.
I read that one track draws a chip for a class and techs that class that night. The first track I ran did something like that. Would check one class a night.
Just wondering about the duration on a non legal cam.

 

[DynoDon]

Cannot give you any information on a non-legal cam If we don’t know what the cam is to determine the duration.

 

[bullerman]

Will use the Dyno Cams Mod 2 Grind as an example. I am sure there are a bunch more. Advertised as a cheater stock cam. The lifts will pass the check but the durations are no where close.
If a track were to check a cam when they did the first duration check at .050 lift the cam would fail with this cam. No need to go any further.
I am just saying I wish our tracks would start teching like they should. I did get the answer to my question. The durations will be way off from stock to cheater stock.