[GTOKIDRH]

Has anyone used the Comp Cams 221-4 cam and what do you have to say about it?

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[Cliff R]

About the only place you could effectively use that cam is in a 350 build with low compression. Not nearly enough cam for the larger engines especially if they have some "squeeze" in them.....IMHO....

[GTOKIDRH]

Considering it for a lo compression 8.6 400 in a full size wagon. A cruiser. Also considering a Pontiac 066 and a summit 2800.

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[25stevem]

It's a good step up from the factory 2 bbl 254 Cam in terms of lift and mid power, and a very mild step up from the factory 066 Cam.

[PunchT37]

I used the old Comp 252H cam in an Olds 350 back in the day. Ping monster. The old worn out factory cam was better. This was a `77 low compress 350.


Just sayin...

[Stan Weiss]

Originally Posted by GTOKIDRH

Considering it for a lo compression 8.6 400 in a full size wagon. A cruiser. Also considering a Pontiac 066 and a summit 2800.

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I have not run this cam so take this with a grain of salt Just going by those numbers I see your engine pinging badly on 87 octane gas. What octane is the hi-test pump gas in your area?

Stan

[PunchT37]

Originally Posted by Stan Weiss

I have not run this cam so take this with a grain of salt Just going by those numbers I see your engine pinging badly on 87 octane gas. What octane is the hi-test pump gas in your area?

Stan

Yep. That`s where I was going. Especially with his closed chamber heads.

2800 a much better choice AND 1/2 the price of the Comp.

[i82much]

definitely apples and oranges, but i ran a 350 chevy with 041 iron heads and a 216@.050 crane fireball on 93 octane with no problems for years. an 8.6 to 1 iron head engine is going to ping with this cam? i understand the XE grinds tend to build compression but wow, I would not have anticipated a problem with that low of a compression ratio!

isn't an 066 around 200 @ .050? an XE grind with an extra 12 degrees of duration at .050 will build more cylinder pressure than the 066?

[Stan Weiss]

Originally Posted by i82much

definitely apples and oranges, but i ran a 350 chevy with 041 iron heads and a 216@.050 crane fireball on 93 octane with no problems for years. an 8.6 to 1 iron head engine is going to ping with this cam? i understand the XE grinds tend to build compression but wow, I would not have anticipated a problem with that low of a compression ratio!

isn't an 066 around 200 @ .050? an XE grind with an extra 12 degrees of duration at .050 will build more cylinder pressure than the 066?

From my standpoint it is the seat-to-seat duration that is the problem. For me the 0.050" do not matter.

Stan

[i82much]

Originally Posted by Stan Weiss

From my standpoint it is the seat-to-seat duration that is the problem. For me the 0.050" do not matter.

Stan

i think this is why so many of us just pick a camshaft that is popular with similar builds. easy to make a mistake unless you really know what you are doing.

old faithful runs great for me. no idea if another cam would be better. monkey see, monkey do right her but i wouldn't change a thing. sometimes it is better to just go with the wisdom of the crowd instead of trying to be clever and do your own thing.

if i was the OP i'd probably do the 2800.

[Cliff R]

" i ran a 350 chevy with 041 iron heads and a 216@.050 crane fireball on 93 octane with no problems for years"

It should have been fine on pump gas with that combination. The Crane Fireball cam will have a LOT of seat timing, considerably more than 256 @ .006".

The SBC 041 heads have EXCELLENT close chambers and if you did what the factory did and ran flat top pistons about .015-.018" in the holes at TDC and .020" steel shim head gaskets it would have ran flawless on pump gas and may not have even needed 93 octane with "normal" timing/fuel curves.........FWIW......

[i82much]

looking at the comp master list. i think that intake lobe on the cam in question is 5441, 256 advertised intake duration and 212 @ .050. the difference between advertised and .050 is 44 degrees.

looking at the high energy hydraulic flat lobes, there are three lobes with 212 @ .050 duration, 5211, 5205, 5207. all three have advertised durations of 260 degrees. so the difference between advertised and .050 is 48 degrees.

so that's only 4 degrees advertised duration difference between XE and high energy lobes with the same .050 duration.

the summit 2801 is 214 @ .050 and 288 advertised, or 74 degrees.

it seems like the comp high energy lobes should cause almost as many problems as the XE lobes?

[i82much]

it looks like that crane I ran with 216 @ .050 was rated at 290 degrees duration. that sound so big! but it was just a pussycat daily driver, really, probably a smidge tamer than OF 1.0 in my current 505.

[GTOKIDRH]

Originally Posted by Stan Weiss

I have not run this cam so take this with a grain of salt Just going by those numbers I see your engine pinging badly on 87 octane gas. What octane is the hi-test pump gas in your area?



Stan

I always run 91in the toys. I run a roller in my '67 GTO similar to this with a little more lift (.515) and 1.6 rockers. 461c.i. 9.45c.r. street ported 670 heads. Runs fine on 91.

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[GTOKIDRH]

Originally Posted by PunchT37

Yep. That`s where I was going. Especially with his closed chamber heads.

2800 a much better choice AND 1/2 the price of the Comp.

The heads on the car now are open chambered 142s.

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[Stan Weiss]

Originally Posted by GTOKIDRH

I always run 91in the toys. I run a roller in my '67 GTO similar to this with a little more lift (.515) and 1.6 rockers. 461c.i. 9.45c.r. street ported 670 heads. Runs fine on 91.

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This cam / card has 18 degrees more seat-to-seat duration than the first cam. That makes a big difference IMO.

Stan

[PunchT37]

Originally Posted by GTOKIDRH

The heads on the car now are open chambered 142s.

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I believe the only open chamber `67 head is the 061.

[GTOKIDRH]

Originally Posted by Stan Weiss

This cam / card has 18 degrees more seat-to-seat duration than the first cam. That makes a big difference IMO.



Stan

In what way? Obviously I am not well educated in cam variables and their effects.

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[GTOKIDRH]

Originally Posted by PunchT37

I believe the only open chamber `67 head is the 061.

Again it may be my lack of knowledge but they have 90cc chambers (8.6:1 c.r.). Please excuse my ignorance. I am here to learn.

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[25stevem]

The 142 head is not a open chamber head.

The 142 and 143 casting where still a 389/421 17 degree valve angle head.

1967 is a very confusing year in that Pontiac had 3 different chamber shapes being used.

Still your better off then if you had the 061 head, as that chamber is very detonation prone.