Help I.d camshaft

[Ypsik10]

Need help figuring out what cam I have.. It's s comp cams product I think I no the specs but what lifters do I use with it? I no its not a hydrolic roller cam but other than that I'm not sure..there is 2268h on the end

 

[1987 GMC Jimmy]

268H is a Comp Cams grind number. The part number is 12-210-2. Here are the specs:

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=73&sb=2

I know you said 2268H, but maybe give it another look? I don't want to tell you the wrong thing, but that's as close as I could get with the info given. If this is your camshaft, the link I gave you offers you two suggestions for lifter kits plus other stuff you need to make it work right (i.e. upgraded springs).

 

[Ypsik10]

Hmm now it's not letting me send pictures..

 

[1987 GMC Jimmy]

Yeah, some people have been having that issue lately. If I was tech savvy, I'd help you out, but I don't know. @Shaggy

 

[Ypsik10]

This is why I'm sort of confused I came up with 12-242-2 so this is a hydrolic flat tappat cam?

 

[1987 GMC Jimmy]

I see what you're saying. The grind number on the 12-242-2 is XE268H, which stands for Extreme Energy. It's a little more aggressive than the 268H, but both are hydraulic flat tappet cams and both need upgraded valve springs. According to the manufacturer, the cams share the same lifter kit. Even though that's a start, I'd feel better if you knew which one of these it was, and I'm sure you would, too. The PN's for those lifter kit options are Comp 812-16 or 858-16.

 

[Ypsik10]

Ok that helps I just wanted to make sure I had the right lifters.. At this point I'm not sure if there is anyway to figure it out unless I sent it to comp cams .. I really don't want to pull it out of my fresh short block..

 

[1987 GMC Jimmy]

Yeah, I guess it works out if your options use the same lifters. The latter number that I gave you is apparently suited for high end engine performance, and I guess the former number is for more generalized performance. They're cheaper to buy from Summit than Comp. Do you already have the lifters, or do you have to order them?

 

[Ypsik10]

I have to order them stock 350 shortblock besides the cam was going to run double hump closed chamber 461 heads will these parts work well with echother? I'm assuming I will have to change the valve springs?

 

[1987 GMC Jimmy]

I have to order them stock 350 shortblock besides the cam was going to run double hump closed chamber 461 heads will these parts work well with echother? I'm assuming I will have to change the valve springs?

Absolutely change the valve springs. The PN for the recommended springs that cross over between the two cams we narrowed it down to is Comp 981-16. Again, these will be cheaper anywhere else but directly from Comp. Will they work well with each other? I'll say for sure that you'll have a good running, reliable, and improved powerplant once you have springs that can take the more aggressive cam. People generally say that, in the present day, there are better SBC setups because the camel hump heads are a more primitive design, and they have the Vortecs and aftermarket heads that can do more than the camel humps ever could, granted the Vortec heads have a ceiling for what valve lift they can handle with stock springs (<0.450), and the parts (intake, valve covers, rockers) that go with the Vortec heads plus the heads themselves are so damned expensive. If these 461 heads were ported and polished by a reputable cylinder head shop with new valves, seals, and guides plus the upgraded springs taken care of, I'd argue that they'd do fairly well with that cam, and you'd have a really good engine on your hands, but with stock 461's, you're gonna have a pretty middle of the road 350. That's just my opinion, though.

 

[Ypsik10]

How much hp should I expect with these heads my cam and I also have full length headers holly 600 carb and I have not bought an intake yet..

 

[MikeB]

Are your pistons dished or flat top? If flat top, the compression ratio could be around 10:1 depending on deck height and gasket thickness. With iron heads, that would be too much for pump gas, maybe even today's premium.

Back in the day, an engine with 10:1 or even 11:1 compression would run fine on premium gas because it had a 98-100 octane rating. Today's premium gas is more like 92-93 octane. Modern high compression engines can run on pump premium because of better combustion chamber designs and knock sensors. Heck. they can even run on regular with some loss of power and fuel mileage.

Also, that cam is not used, is it?

 

[1987 GMC Jimmy]

I would say 325 (give or take) horsepower. The headers help, but the big gains are always gonna come from how well your heads flow combined with how effective your cam is in conjunction with your heads. With the aforementioned head work, plus your cam intake, headers, I would venture a guess of 400 horsepower. This is just me saying this, though. I'd like someone else to chime in.

 

[Ypsik10]

Are your pistons dished or flat top? If flat top, the compression ratio could be around 10:1 depending on deck height and gasket thickness. With iron heads, that would be too much for pump gas, maybe even today's premium.

Back in the day, an engine with 10:1 or even 11:1 compression would run fine on premium gas because it had a 98-100 octane rating. Today's premium gas is more like 92-93 octane. Modern high compression engines can run on pump premium because of better combustion chamber designs and knock sensors. Heck. they can even run on regular with some loss of power and fuel mileage.

Also, that cam is not used, is it?

Cam is used it was in the shortblock I bought and rebuilt..I just cleaned it up the best I could with a brass wire wheel I also lauded a strait edge on it to make sure it wasn't bent in anyway .. Just ran into a new problem heads I wanted to pick up tomorrow (461 casting 250$ seem to be slightly damaged I blew it up for a closer look and inquired about it.. He claims it won't affect gasket sealing... Should I stay far away from these heads? Here is the cl add if anyone wants to take a look thanks all your help is much appreciated !

 

[Ypsik10]

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