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CompCams Roller Cam/Rocker Conversion Questions

4K views 21 replies 7 participants last post by  darkmaniac7 
#1 ·
Hey everybody I've been checking everywhere for install notes, stories, guides, etc. to try and make sure I have everything ready and am prepared for this install this weekend, I was really just wondering if anyone knew of a site/article or post that had a step by step with pictures for a BBC? I don't anticipate any problems but it's always good to have a fallback if I get stuck at any point.


I've also read that I probably neet get some new pushrods, a thrust bearing? and maybe a bronze dizzy gear/Fuel pump pushrod?

Also According to Paul Right the Comp Cams rockers p/n: 1411-16 are basically garbage and so from the response I see I should probably go with some Scorpions/Summit rockers?

the Engine is a Mark IV 454 LS5, here's the cam here:

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=435&sb=2

and the kit here: http://www.compperformancegroupstor...re_Code=CC&Screen=PROD&Product_Code=K11-430-8

Please let me know if you have any advice or suggestions other than what I listed thanks a ton!
 
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#4 · (Edited)
forgot about that, thanks! Being that this project will be with the motor in the car i'm sure this will be "fun" XD

Edit: Since i've been having issues with my Carb I think this will be the time to upgrade that as well, i'll probably go for the 870cfm Street Avenger, given the specs: Headers, 10.5:1 Compression, New Cam, Exhaust, Aftermarket Intake, bored .030, ported & Polished I think this would probably be best bang for the buck, especially at $350 new. what do y'all think?
 
#5 · (Edited)
Ok got everything installed correctly I think, but i'm still not getting it to start. the timing chain is lined up and was verified by a straight edge. i've done valve lashings, getting spark, fuel flow is fine but it never starts...any Ideas what could be a likely culprit? it doesn't even backfire like the distributor is 180 out...i'll post some pictures in a bit of the timing chain, distributor, rocker arms/springs etc. in a moment.

Edit; Timing chain pics....I think photobucket resized them though so quality may not be as clear.









 
#8 ·
Wait, hold on. Turn the crank 1 revolution and the 2 will line up. For every 2 turns of the crank, the cam rotates once. So they will line up and they will be 180 apart every other rotation. Check the rocker arms. You should be ready to fire on #1 where the engine is now. So check your distributor and make sure the rotor is pointed at #1.
 
#12 ·
You can do both dots straight up, but it's the wrong way to do it. The reason I say that is it gives you more of a chance to be off a tooth. I know two guys that did that. One I told him do it his way. Then I told him to turn the engine over by hand with cam dot down and crank dot up. He was off a tooth.

Best to install cam dot down and crank dot up.
 
#9 ·
ok well.... this is weird, got a buddy of mine to help me check and double check everything, he's built tons of BBC's and what we found was we think that compcams gave us a Marine reverse rotation cam on accident.....because the fuel is shooting out of the carb, no fuel is making it down to the spark plugs, and is actually sucking in the spark plug hole, in fact we were able to get it to ignite by putting ether in the tailpipe and the flame shot out the intake.....the Marine cam is all that makes sense....and we've already done the valve lashings as well...I've never heard of this....any other ideas?
 
#10 ·
Cam was in the correct position, TDC and distributor is pointing at no.1 cylinder...wednesday I'll be taking it to the guy I bought the cam from, he has a racing shop and after explaining what happened etc. he said he would work on it with me....he doesn't think they sent me the wrong one but that a valve isn't seated properly. I didn't think that would be all that likely since I didn't remove the heads and none of the valves dropped into the cylinder while I was changing out the guides/rockers/pushrods etc....I guess i'll figure out come wed. evening.
 
#13 · (Edited)
You can put #1 anywhere on the cap you choose or where the book dictates if you want as long as you point the rotor to the one you want on the cap. TDC comes around once and it will be sucking air on #1 cylinder. TDC comes around again and it's building(blowing compression) out #1 cylinder. So when it's blowing compression(both valves will be shut) out of #1 with your thumb or finger over the spark plug hole you need to stop the balancer at your initial timing or 0 mark. Better to stop it at your initial timing of 12-18 degrees depending on what you use. As long as you mark your #1 on the cap then route your spark plugs in the right firing order on the cap the direction the rotor turns when you spin the engine. You should be 100% the distributor is right, it's very simple once you have learned and it will fire every time if all else is good(valve setting, fuel and building compression).
 
#11 ·
Pull your driver's side valve cover off, set the balancer to zero, turn the crank clockwise and you'll see the exhaust valve open first then the intake valve if the rotation is right. I don't see a cam thrust button in your photos-did you install one?-very important with a roller cam!
 
#14 ·
Ok, thanks guys for the support, I had it taken to the shop where I bought the parts from, the owner had a race shop so we took it their and over the course of about 2 days we figured out a couple things and stuff we did wrong...

1. Buddy of mine had the Crankshaft off about 65*

2. Since Crank was off, Distributor was off about the same.

3. Valve lashing were redone, may or may not have had an impact

4. the guy we had torquing the pushrod guide plates didn't use a torque wrench as we said so he didn't torque it the proper in. # so we had to take them all off and redo them.

5. New Carb needed to be tuned a tad.

and now? It's working phenomenally, the sound is exactly what I wanted and the upgrade from a 650 Holley to an 880 made quite the difference in power as well....currently the throttle cable is too short so I only get about 75% throttle...afraid I might need wheelie bars after replacing that cable since the car almost lifts off as it is...

Anyway as I said thanks for the help/guidance been a great learning experience and made the car even more fun to drive.


Also anyone know what may cause a random backfire? I've driven it breaking it in about 4 hours today and while the clutch was pushed in i lightly tapped the accelerator and got a backfire...this happened 2x today.
 
#15 ·
Well a bit of an update. after nearly a month one of the lifter bars rivets popped off and turned the lifter sidewAys causing a blown lobe on the cam. Hopefully comp won't be *******s about it and will RMA their product. I should have waited a bit and researched more and gone with a pair of Straub lifters like the Chevelle guys said.....anyways here's a picture.

 
#18 · (Edited)
The Comp roller cams are cast core. And there lifters are made overseas.

For the Money Herbert roller cams are 4340 billet, and Herbert roller lifters are morel and have been for years before anyone even knew about them.

FYI
Al

 
#19 · (Edited)
If comp kicks it back to me (boy I know how manufacturers love to kick the buck on to someone else) I'll go with those. dammit I wish i'd have researched the parts better! I could have bought my entire kit through herbert and come out about $500 cheaper with better quality.

Edit: Al, I'm looking at going with this cam and these lifters, if I use the springs, rockers and pushrods from the comp set, will everything else still work correctly?

http://www.dougherbert.com/index.php?main_page=product_info&cPath=83_84_88_661_1229&products_id=9888

http://www.dougherbert.com/cams-val...tical-bar-hydraulic-roller-lifters-37623.html
 
#20 · (Edited)
From looking at the website it looks like they both have similar spring pressure, and lifters.

http://www.compperformancegroupstor...Store_Code=CC&Screen=PROD&Product_Code=924-16

http://www.compperformancegroupstor...Store_Code=CC&Screen=PROD&Product_Code=854-16

Also, Comp is actually going to warranty the Cam, which was a remarkably easy process, I thought for sure they'd ask if the installer was ASE certified, done at a sanctioned facility or a million other ways manufacturer's duck out on footing the bill....all the same though from what Al said I think i'm going in the direction of Doug Herbert Cam's...so I may just keep the replacement comp lifters and cam as a backup. Especially since on the last set I bought with the 11-430-9 Kit would be billet...was not.
 
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