hi everyone, i tried doing a search but could only come up with information regarding one of the camshafts in question. i have a pretty much stock 85 305 tpi in my car, see my sig for all the small mods i've done. don't ask me how, but it has the cv-12 camshaft, which from what little info i have found on it, is basically the LO3 camshaft. the engine was rebuilt and whoever rebuilt it didn't bother to actually search for the right cam. now i'm gonna change it to a summit cam, and i have a few choices listed below.

Summit part # 1102
Intake Duration 050 inch Lift 204
Exhaust Duration 050 inch Lift 214
Advertised Intake Duration 262
Advertised Exhaust Duration 272
Intake Valve Lift with Factory Rocker Arm Ratio 0.420
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.442
Lobe Separation (degrees) 112

Summit part # 1104
Intake Duration 050 inch Lift 224
Exhaust Duration 050 inch Lift 224
Advertised Intake Duration 282
Advertised Exhaust Duration 282
Intake Valve Lift with Factory Rocker Arm Ratio 0.465
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.465
Lobe Separation (degrees) 114

Summit part # 1105
Intake Duration 050 inch Lift 224
Exhaust Duration 050 inch Lift 234
Advertised Intake Duration 282
Advertised Exhaust Duration 292
Intake Valve Lift with Factory Rocker Arm Ratio 0.465
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.488
Lobe Separation (degrees) 114

Which cam is better for the engine? it's a stock motor; no internal mods done to it. it does have a hypertech thermomaster chip though. i don't want to change valve springs right now; i'm just looking for a cam that will increase performance without me changing valve springs right now. also, the stock ecm has to like it. i have the 416 head castings and will most likely get them ported someday in the next couple years.

let me know which cam you guys think is better for my engine and preferences.

thanks!
kev

 

1102 is what I would go with.

1104:
is a hare on the aggressive side for duration and probably require a converter to get it "just right." Just because you have a hyper-blah chip, doesn't mean it does anything for allowing a larger cam, because, in all reality, it doesn't. The ONLY way to get a PROM for a larger chip is to tune it yourself or have someone custom burn one for you. Factory heads have the handicapped exhaust port. They benifit from the dual pattern grinds moreso than a single.

1105:
if you thought 1104 was aggressive, this one will be worse. On top of that, as far as lift is concerned, it won't fit under the factory clearances (guide boss and the bottom of the retainer)

 

I would consider soemthing between the 2 & 4, something like


Intake Duration 050 inch Lift .218
Exhaust Duration 050 inch Lift .224
Advertised Intake Duration 270
Advertised Exhaust Duration 276
Intake Valve Lift with Factory Rocker Arm Ratio 0.495
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.502
Lobe Separation (degrees) 114

This is the specs for the SLP cam 51006 I have the 51002 but I find I wish I had the 51006.

Unfortunately the SLP cams are for roller cam engines, which were not into production until 1987.

I would also consider going to a 350, which will help tons.

Hope this helps.

 

If I'm not mistaken, you have a computer controlled car (1988) but an 1985 enine having factory hydraulic flat tappet lifters. Check out www.compcams.com pg 130 Xtreme Energy cams, part # 12-256-4, its a 212/218 cam at .449"/.456" lift with 112*LSA.

Either this one or the cam listed just below it on pg 130.

 

hey guys that helps me out. anyway, i looked for a cam between 1002 and 1104, so i figured the 1103 would be a good start. here are those specs:

Basic Operating RPM Range 2,000-4,500 RPM
Intake Duration 050 inch Lift 214
Exhaust Duration 050 inch Lift 224
Advertised Intake Duration 272
Advertised Exhaust Duration 282
Intake Valve Lift with Factory Rocker Arm Ratio 0.442
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.465
Lobe Separation (degrees) 112

I think that lift kills it because it won't clear my valve components and it probably has more lift than the stock springs can handle.

what do you guys think?

kev

 

doc- yes i have an 88 car with an 85 engine. the entire engine wiring harness and ecm were swapped over to my car. so i have the 85 LB9 and all the engine management stuff in my 88 car.

kevin

 

Yea, your choice is close to what I posted, I think its a good choice, but I am far from a cam export. Its just that if that was my car, I would install what I recommended, thats all.

Good luck, lets us know how it goes.

 

thanks again for your help. i looked at the cam you reccomended, doc, and its defenitely a cam i would highly consider. however, pricewise, i don't have that much money for the part. but, then again, might as well cough it up now to get a better cam instead of wishing i had, then installing it down the road, costing me more money. i'll consider it, and post back when i purchase the cam. installation probably won't be done for a month or so, though. while i'm under there, i'll replace the timing chain/gears and the water pump while it's off.

thanks again!

kev