As stated in my previous thread I have an 86 Iroc with a 1974 350 block. I am trying to fiquire out why it does not run right. I have the hanes repair manual that covers camaros from 1982-1992. The cam lobe lift specs that are listed in the manual are 0.269 for the intake and 0.276 for the exhaust. I was under the impession that there were 2 different cams used that year. The manual only has specs for one camshaft. On this website in the 86 Iroc imformation it states the lobe lift for the intake is 0.350 and the exhaust is 0.385. Are these numbers both correct. I will be checking in the next couple of weeks what cam I have in my engine but I am wondering that if the original owner put the 86 cam in the 74 350 block that has a jet performance chip for a 87 5.7 liter what kind of problems my car would be having.

 

Well no, that can't be right, if the lobe lift was .350", then the valve lift would be over .500" stock. That is the valve lift there, .350" and .385".

.269x1.5 = .403"
.276 x 1.5 = .414"
This would be the more aggressive cam for that year.

Which engine is this? '86 carb? LG4? Or '86 TPI engine ? Those two had different cams IIRC.

I don't think whichever cam is in it is what's causing the problem. What IS the problem anyway?

 

the engine is a 1974 350 block with i am guessing an 87 tpi plenuim. the problem is that the car idles in park or neutral at 1500-1750 rpms. it did not start doing this till after I put a new belt and alternator pully on the car because the alternator I had just put in the nut was not tight on there. I also replaced the battery because driving several days without one killed it. When I bought the car i noticed acouple of days after that it would stall oout at low speeds. 4 speed 700r4. I checked the Prom and it was the stock prom for the 86 305 tpi. so i put in a jet performance chip for an 87 tpi.

 

Then it really has nothing to do with the cam eh?
Look for the typical vacuum leaks. After that, it'd most likely be a computer/injection type of issue - which i'll stay at least 50' away from...