12V Tappets VS CR Tappets

kino_fab

kino_fab

KTPA Tech Official
Joined
Aug 19, 2007
Messages
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Well we figured out all the troubles with Fireman450's valve train. For some reason the guy who was supposed to grind the cam was backed up as sent it off to Comp Cams to have them grind it. We got it back (6weeks later), put it in and have had all sorts of problems. Finally swapped it out for a stocker and the truck ran alot better, although it was only on 5 cylinders because the junk regrind destroyed the #6 intake tappet. After further investigation, we found out that Comp Cams basically ground a set of lobes for a 700+hp hydrolic roller gasser. Idiots these days.

Any way. Since Lynn's truck is going to be down for a bit, we are going to have a TRUSTED cam profiler grind one for us. We are debating on going with a set of CR tappets instead of the 12V tappets. Either way, our profiler needs the exact deminsions of the tappets that we are going to be using.

So, getting down to the question, does anyone have a visual comparison chart of every exact deminsion of the 2 types of tappets.

Thanks in advance!!!!
 
Not sure if this will help but these are all three from left to right 12v 24v CR.
 

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Pretty much all we need is the base diameter of the tappet so our profiler will know how agressive he can go.

Lynn
 
Are you still running a cam driven lift pump? CR tappets have intererence with the lift pump lobes.
 
I think that the 12v are 1.1 and 24v are 1.3 and Cr are 1.5. Dont hold me to these spec I may be wrong. maybe some else will know for sure. good luck.:rockwoot:
 
With Putting a H2 Cam in my 01, can I use CR tappets and then just adjust valve lash accordingly to the different size tappet, or do I need to stick to the 24V tappet for mine?

Lavon
 
kino_fab said:
Any way. Since Lynn's truck is going to be down for a bit, we are going to have a TRUSTED cam profiler grind one for us. We are debating on going with a set of CR tappets instead of the 12V tappets. Either way, our profiler needs the exact deminsions of the tappets that we are going to be using.
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may I suggest diesel pros bill fletcher knows his $hit when it comes to cams especially the details. Not to many people have the r@d race experience that he has and it shows"the truck that won the diesel power challenge runs his cam" Good luck to ya no matter who u choose it sucks you got a bad product, hopefully u got a refund on it at the least.
 
LAmiller said:
With Putting a H2 Cam in my 01, can I use CR tappets and then just adjust valve lash accordingly to the different size tappet, or do I need to stick to the 24V tappet for mine?

Lavon
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That depends on you cam, if you have an H2 with a mechanical fuel pump lobe then you need 24V tappets. If it doesnt then it dont really matter.

The H2 isnt aggressive enough to wattent a bigger tappet.


IIRC the CR tappets are 1.5" or there abouts. You could get real tricky and get a roller.....
 
roachie said:
IIRC the CR tappets are 1.5" or there abouts. You could get real tricky and get a roller.....
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Evidently the guys at Comp Cams thought we were going with a roller. Wish I could find that comparison pic we took before we installed it. HUGE difference in the lobe profile. Where the stocker looked to have a sharp pointed crown, the regrind seemed to have a 1" radius lol.
 
roachie said:
That depends on you cam, if you have an H2 with a mechanical fuel pump lobe then you need 24V tappets. If it doesnt then it dont really matter.

The H2 isnt aggressive enough to wattent a bigger tappet.


IIRC the CR tappets are 1.5" or there abouts. You could get real tricky and get a roller.....
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Not true...I used the CT tappets in my 95 with the H2 and mechanical pump...works just fine;)


Lavon, use the CR tappets!
Chris
 
The 24 valve tappet will be fine , for all but some really extreme profiles . A roller would be a step backwards , you can not achieve the kind of profile with a roller wheel that you can with a large diameter mushroom tappet .
 
Anything else has to be done to use the CR tappets besides the fuel pump lobe?
 
no. Unless someone corrects me.

I plan on putting some CR tappets in my 12v here pretty soon.

Lance
 
CR tappets in my 12v's here...both with H2's, one with the mechanical lift pump. No problem!

Chris
 
Signature600 said:
CR tappets in my 12v's here...both with H2's, one with the mechanical lift pump. No problem!

Chris
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Ditto. CR-size Ceramic tappets, Spartan drop-in, 12valve. It ran a mechanical lift pump briefly before installing the FASS.
 
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