guys - need your help for my BBC 468 Hot Street Application:

what are your opinions on the -8 Series of Roller Cams from Comp? For example, the 11-771-8. These are the "standard" core roller cams, not the harder Billet Core I'm told. These are for street applications I'm told - not competitive racing.

I'm considering whether or not to use one of these for my street application. Mine is a muscle car - driven 500-1000 miles per year - saturday cruiser type of situation. RPM will be limited to about 6000.

I'm told these cams have the correct fuel pump push rod and distributor drive gear material compatatable with "standard" fuel pump rods and distributors. Hence - for street use. I was also told by some guys that because of that, the cam cores are "softer" and wont last as long - more prone to early failure in some circumstances.

The camshafts (-8 vs -9 series) are about the same price - so that is not a concern there. But, if I get a -9 series I was told I will have to upgrade my distributor gear and fuel pump rod which could be $100.

This is all confusing to me. Am I thinking to much on this? I often do that and get frustrated.

Comp makes the -8 series cams available in kits - so it's very easy for a guy like me to order 1 part (the kit) and get everything and not kill myself with "over thinking" the situation and getting in over my head.

So my question is: Should I just buy the kit and get it over with, or am I better off buying the individual components (cam, lifters, springs, retainers, locks, seals, etc). If I buy the individual components I was told I have to order the cam as a custom grind from Comp (-9 Series), and then get the distributor gear and fuel pump rods seperately. :confused:

I got a billet core with cast gear from Comp. That is the way to go if they have a core. Have an electric fuel pump.

I got a billet core with cast gear from Comp. That is the way to go if they have a core. Have an electric fuel pump.

not sure what you mean by billet core with cast gear. You mean the distributor gear portion of the cam is suitable for a cast dist gear, or do you mean you had to change the distributor gear to accomodate the billet core?

not sure what you mean by billet core with cast gear. You mean the distributor gear portion of the cam is suitable for a cast dist gear, or do you mean you had to change the distributor gear to accomodate the billet core?

Correct. A -9 core is billet and then you specify you want a cast distributor gear so they machine the cam blank down at the rear and press & pin on a cast distributor gear. Then you can run a melonized gear on your distributor and get long life from the gears. That's what I now run after having terrible luck with 2 -8 cam cores fail in my own engine and seeing failures of several other -8 core cams in other applications.

The -8 cores are picky about distributor gears too... I know that if you run an out of the box MSD distributor gear on them they will chew each other to pieces (I had this happen a couple of times about 3-4 years ago.) The -8 cores can also wipe the lobes off once spring pressures get up around 400+ lbs open-- but it's a crapshoot.

Go with a -9 core and special order the cast distributor gear option, then buy a genuine GM melonized distributor gear, and don't worry about it.

Correct. A -9 core is billet and then you specify you want a cast distributor gear so they machine the cam blank down at the rear and press & pin on a cast distributor gear. Then you can run a melonized gear on your distributor and get long life from the gears. That's what I now run after having terrible luck with 2 -8 cam cores fail in my own engine and seeing failures of several other -8 core cams in other applications.

The -8 cores are picky about distributor gears too... I know that if you run an out of the box MSD distributor gear on them they will chew each other to pieces (I had this happen a couple of times about 3-4 years ago.) The -8 cores can also wipe the lobes off once spring pressures get up around 400+ lbs open-- but it's a crapshoot.

Go with a -9 core and special order the cast distributor gear option, then buy a genuine GM melonized distributor gear, and don't worry about it.

where do I find a GM Melonized distributor gear. I just checked Summit - no search results. They just show bronze, steel, or composite. some are very expensive ($100)

One more thing. How do I order a Comp Cams Billet Cam (-9 series) if it's not one of the ones they have listed in the catalog? I want to order a Billet cam with the same specs as the 11-771-8 cam. Should I call Comp Cams to do this or must I do it through one of their distributors or resellers?

where do I find a GM Melonized distributor gear. I just checked Summit - no search results. They just show bronze, steel, or composite. some are very expensive ($100)

You buy them directly over the counter at a GM dealership or from GM parts direct.... #10456513. Summit stocks them too.

Keep in mind if you have a distributor with a .500" diameter shaft (i.e. MSD) the gear needs to be opened up... and Mike Lewis (Wolfplace) always has some of those in stock and ready to go.

You buy them directly over the counter at a GM dealership or from GM parts direct.... #10456513. Summit stocks them too.

Keep in mind if you have a distributor with a .500" diameter shaft (i.e. MSD) the gear needs to be opened up... and Mike Lewis (Wolfplace) always has some of those in stock and ready to go.

what do you mean opened up? and yes I have a MSD distributor.

GM shafts are .490" MSD .500.

Call Comp and special order direct. About the same $.

the CC cast roller cam is another one of the things that's been beaten to death here. Keep in mind, the billet steel roller cam is the "standard" deal. the CC cast iron roller is the new "innovation." You want a steel billet roller with a pressed on iron gear. accept no substitutes. Call them, they'll know exactly what you're talking about. I'm running a plain old iron distributor gear as sold on millions of SB and BB chevies since forever. Avoid the HV/HP oil pump deal and you're good to go.

I've been running a stock GM gear on a regular distributor, and then a stock MSD gear when I added it to the mix on my Engle steel roller with an iron gear. I also run a HV pump with pretty serious oil pressure. It's been this way for 7+ years now with no issues on cam or dist gears.

The Engle was made on a Crane core FWIW.


Just order whatever cam you want with the pressed on iron gear on a steel core. You'll be fine. If you run a mechanical fuel pump you will need a bronze tip pushrod to run on the steel cam.


JIM

Billet cores with the everwear gear option allows one to run a cast iron gear. The melonite type gear is available in the MSD configuration of .501" and runs about $50. For an all out competition style engine you need to run the better core.

I remove some cams from the Chevrolet crate motors and this is how I reorder the cams. Steel cam with cast gear, it lets me to use the factory distrbutor gears without a problem. And these aren't mechancial rollers they are steel with there hydralic rollers.

I also order from Comp Cams the same setup. Would never use any cast cam with mechanical rollers. This works with the 819 lifters and is fine for sure on the street

Harry P.Hunter

Billet cores with the everwear gear option allows one to run a cast iron gear. The melonite type gear is available in the MSD configuration of .501" and runs about $50. For an all out competition style engine you need to run the better core.

I'd say run the better -9 core with "street" setups too. I have seen a couple of Comp cast core hydraulic roller setups where the lobes were starting to go away, open pressures were in the 400-420# range.

The way I look at it, it's cheap insurance. The cost difference between a -8 cast core to a -9 billet core with the iron gear option is much cheaper than cleaning up after a cast core cam failure. I lost a comp -8 core due to MSD distributor gear incompatibility; it failed completely (i.e. nothing left of the gear teeth) in just over 2000 miles. Wasn't even running a HV oil pump, it was simply material incompatibility (comp blamed MSD, MSD blamed comp.) The debris generated took out every bearing in the engine and the oil pump.

Troy,

Just out of curiosity, did you have the oil filter bypass plugged when this happened?

Doc

Troy,

Just out of curiosity, did you have the oil filter bypass plugged when this happened?

Doc

Unfortunately, no I didn't have it plugged at that time. If I had there's a decent chance I probably would have got away with just changing the cam & oil pump. I plugged it right after that teardown & freshening.

Even if I had the bypass plugged when it fragged the gear I would still have torn the engine down, the oil pump was in bad shape and there was so much debris in the filter I wouldn't take the chance of sticking it back on the road.

After that 2nd -8 cam & gear failed, I went back and looked at my 1st cam (which was also a -8) and distributor gear in more detail. They had about 10K miles on them. The distributor gear & that particular cam was about 20% worn.

Why my 2nd cam & new gear failed completely after 2K while my previous made it 10K with substantially less (but still abnormal) wear I don't know.

My 3rd cam was also on a -8 core but this time I used a Melonized GM gear rather than the MSD gears which were 2 for 2 in my enigne. I put about 10K miles on this cam & GM gear and had zero perceptible wear. Right about this time I had another engine I put together with a -8 core hydraulic roller running about 400# open pressure plus a hydra rev kit chew up a lobe and was starting to "track" 2 others. I confirmed this problem with Mike Lewis and a couple of others so I yanked my engine again since my spring pressures were in the same neighboorhood and had the same cam ground on the -9 core with the everwear gear. My cam didn't show any lobe wear at that time but I wasn't going to chance another cam failure.

I now run a -9 billet core with the everwear gear option and a GM Melonized gear on my distributor. I have about 10K miles on the new cam & gear, everything looks brand new. I would not run any other combination for a roller setup.

Billet cores with the everwear gear option allows one to run a cast iron gear. The melonite type gear is available in the MSD configuration of .501" and runs about $50. For an all out competition style engine you need to run the better core.

It's replies such as this one that's confusing poor ol' Lee. His question about this entire issue was answered back in the beginning of this month!!

It would be inherently more important to use the "best of the best" in a "streeter" where you are sitting at "stop-lights", caught in "stop & go" traffic, jumping in your "ride" and "hangin out" with the guys, than in a "non-registered" weekend warrior!!

I can't remember the last time I spotted a "dragster", registered with "tags" at a "red light"??

Dedicated quarter-mile units are "easier" on ALL internals than any "streeter" acting like a "track-only" racecar!

While I'm here on this particular issue I'd like to pass along another "tip" for what it's worth: You've got to separate the SB issues from the BB ones, the SB's will have just about "zero" solid-roller failures. You almost don't hear of any!

Up here on this forum you have a member who's very familiar with a unit I built in 1990. I believe his name is "RedSS454". He's seen this "ride", a '62 black Vette with "graphics" on the side, hanging out on the "avenue" and got to speak with the owner. He thought it was a BB unit by the sound, he later found it to be a 350 SB. It runs a solid-roller platform and was back in here this past year for a "freshen-up".

The SAME (Crane/Blue-Racer) lifters from 1990 stayed inside, are in there tonight, that's over 17 years now!! You CANNOT equate the SB's and BB's on an equal footing in a total "street" environment?

Take this "tip" and give it some thought! I have a relatively high number of BB solid-rollers on Long Island as well, street-driven, nice weather drivers. Almost every one has 1.6 rockers on the intakes and 1.5's on the exhausts.
Been doing this for some time now! From "rock-solid" testing, you CANNOT feel any "seat-of-the-pants" difference with the "reduced" R.A. ratios. The lifters DO live longer!

No "synthetic" oils, straight 40 Valvoline "Race", NO blocked by-passes, and "rev-kits" where possible. Don't have too many of these in service anymore due to block design!

We've had extremely good luck with all our roller builds. I can't remember the last roller cam failure I had, but ALL failed cams are returned to the vendor's and as I've stated, I don't remember the last one. The most recent cam sent back was due to a "pin" falling out!! It was not my build, it was a "carry-in" from another shop!

Thanks, Gary in N.Y.

P.S. Lee, it was my understanding your "guy" was setting you up with the cam package!! You need the "-9" blank, you need the "cast" drive-gear", and you need the "distributor-modification" to get add'l oil to "cool" the gears. The 819-16 tappets have the add'l oiling also and you DON'T need the +.300" talls in a "standard" MK-IV! Good luck! If you don't pay close attention to many here, you WILL be back in short order with MORE issues!! You can "bet-the-ranch" on it!