Max RPM on non billet cam???

S

sigmon03

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Just curious on the opinions out there. I am trying to stay away from the billet cam just to avoid the boring of the cam journals, regrinding of billet tappets etc. What kind of RPM can aftermarket cams run like the H2/H3's etc. Looking for 4500+ on the track, and am planning on balancing the bottom end etc.

Thanks

Scott
 
I think Mr. Garrett ran a non-billet type cam but is now switching over, I know he had a couple spikes of RPM when things broke and his cam stayed together he also was in the neighborhood of 4500 or so down the track. I say if funds are their do the billet but thats my uneducated guess.
Brandon
 
I have hit 4500 several times, another issue is the loading the pump puts on the cam gear. 13mm pumps are harder on cams than a 12mm. What size charger are you gonna run?
 
I run a non billet cam i leave the line at 5500 and turn 45-4800 down the track with a 13mm pump the only problem i have had with the cam is it broke the bolt that holds the cam gear on. In doing that the cam slid back letting and the loab that runs the mechanical fuel pump was hitting #5 exhaust valve holding it open. Not a big deal but required pulling the front off to fix. If you dont have the money get a good custom grind but billet is the way to go im switching over for next season myself.
 
sigmon03 said:
Just curious on the opinions out there. I am trying to stay away from the billet cam just to avoid the boring of the cam journals, regrinding of billet tappets etc. What kind of RPM can aftermarket cams run like the H2/H3's etc. Looking for 4500+ on the track, and am planning on balancing the bottom end etc.

Thanks

Scott
Click to expand...

You can run a billet cam with out boring the cam journals. I wouldn't Run a regrind much over 4500 RPM. What Lbs valve springs are you guys running with a regrind? That is more of the issue than the regind itself.
 
I would also recommend welding the cam to the gear and a billet cam retainer.
 
I am running an S400 hybrid as a single charger, and 60lbs valve springs.

So is it true that if the lobe height isnt so big that they wont clear the journals that you dont have to bore it and put busings in? I thought the billet cam had to ride on busings so as to not eat away at the block? I thought that was the reason for billet tappets also? Am I totally worng with this?

Thanks again

Scott

hahaha just realized i am logged in as my buddy.....this post is for ssigmon
 
The cam lobes can't be bigger than the journals. The reason for putting bushing in the block is for rpm the bushing are a little wider some have oiling grooves. Retaining the cam gear is important also the key is just for timing/placement and the press fit is to keep it on and with high rpm and sudden quick accell/decel the cam gear can walk off the cam nose.

IKE
 
I also ran a helix sttle cam and have hit 5500 many times and run 4400-4600 down track with absolutly no problems
 
How many times???

You need to change your Avatar:poke: ``:badidea:
 
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silver03 said:
I would also recommend welding the cam to the gear.
Click to expand...

Im not to sure thats a good idea, Bad things happen to metal that are hardend when you try to weld them without anealing them first, it will become brittle and may make it worse then it was pressed on with a bolt. Just my opinion.
 
Try a Formula 1 Helix3 with a bolt on gear. you can run plenty of RPM's with it and no fly-cutting.
 
DISTURBED said:
I run a non billet cam i leave the line at 5500 and turn 45-4800 down the track with a 13mm pump the only problem i have had with the cam is it broke the bolt that holds the cam gear on. In doing that the cam slid back letting and the loab that runs the mechanical fuel pump was hitting #5 exhaust valve holding it open. Not a big deal but required pulling the front off to fix. If you dont have the money get a good custom grind but billet is the way to go im switching over for next season myself.
Click to expand...


He said he broke the bolt!
 
I don't think a regrind or a helix would have much to do with the bolt breaking.
 
On the Helix cams the mounting bolt travels through the camshaft to the second bearing journal. This serves a multi purpose: The first is to hold the gear securely to the cams nose and the other is to provide added rigidity to the cam billet itself. Cummins camshafts break most often in the area between the first and second bearing journal. The M12 fastener used is torqued right at 80 ft lbs for positive engagement.
 
Im not sure what you mean by Helix, but i do have a custom grind on the cam and the pistons have pretty good size valve releafs cut in them wont get into details i also have the billet front cover with front bearing that cares the gear, the motor was built completly by scheid if you look on their website the motor on the dyno stand is mine.
 
SMOKIN93 said:
On the Helix cams the mounting bolt travels through the camshaft to the second bearing journal. This serves a multi purpose: The first is to hold the gear securely to the cams nose and the other is to provide added rigidity to the cam billet itself. Cummins camshafts break most often in the area between the first and second bearing journal. The M12 fastener used is torqued right at 80 ft lbs for positive engagement.
Click to expand...
sorry still typing when you posted it is not a helix cam by your description
 
SMOKIN93 said:
On the Helix cams the mounting bolt travels through the camshaft to the second bearing journal. This serves a multi purpose: The first is to hold the gear securely to the cams nose and the other is to provide added rigidity to the cam billet itself. Cummins camshafts break most often in the area between the first and second bearing journal. The M12 fastener used is torqued right at 80 ft lbs for positive engagement.
Click to expand...


Your saying the cam flexing may have broke his bolt. I can see that being possible, but I am saying what broke the bolt more than anything is the loads on the bevel gear of the cam, pushing the gear out and walking it off the cam. There was enough force that it popped the bolt.
Hopefully Don can chime in, but that was not how I torqued my bolt.
It is a yield fastener. I torqued to a certain torque and then gave 90(I think) more degrees. That is how I was told to do it.
 
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