cam lift question

ok now im getting to the part where i need to choose a cam for my motor. im just curious as to how much lift i can run without replacing the stock converter. thanks

-matt  

Matt, lots of things come into play when choosing a cam. What size of motor? What gears and tire size? Compression ratio and other engine mods? How heavy is the car? What is your intended use of the car?
I know that's a lot of questions bu that's what it takes to make an educated pick for your cam. If you just go with "the most lift with a stock converter" you will likely be unhappy with the end result. Let us know the answers to these questions and we will gladly help you out.
Steve  
Trying to help... 'cause we don't all have to learn the hard way!

thanks. but i hit a big snag a couple days ago. i got my block back from the machine shop and when they checked it for cracks he found one in cylinder 1. it slipped by me i guess when i checked it myself. so im still not sure what size engine but i have decided to buy a stall converter. i want the car to be streetable so i figure a 2500-2800 stall will be plenty for the street. thanks

-matt  

Matt, did the machine shop suggest sleeving the cylinder? If you are dealing with a Pontiac V8, remember that these blocks are worth saving...they aren't making anymore of them! Before you buy a 2500-2800 stall converter, consider the rpm range of the motor. If you are building a mild Pontiac V8 that won't see over 5500rpm, you are giving up alot of useful rpm range with such a high stall. We aren't talking about 350 Chevy's here, Pontiacs make torque doen low and many don't need a converter that loose.
Steve  
Trying to help... 'cause we don't all have to learn the hard way!

I second that.

I have a buick regal that runs in the 12's with a 350 pontiac and still using stock converter.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

no the machine shop didnt but my brother did talk about sleeving it. the only problem is that it is a crack that goes right to the water jacket. will water be able to leak past the sleeve?? ive been looking at this cam in my classic industries book. it is a comp cam that they say is a reproduction of the cam that was in the '70 455 and '69 400. it has .516 lift with 230 deg intake and 240 deg exhaust duration. my brother had to change his converter in his sbc to use a similar but smaller cam.

-matt  

Cam lift is the wrong parameter to be using in evaluating what cam you should be using.  Except for the RAIV clone that you cite (.515/230/240), every other Pontiac factory cam was about 0.400 lift, including the 73-74 455SD.  That was for the very good reason that stock Pontiac heads except for the RAIV/RAV/SD heads do not flow more above about that lift.

The other questions raised by previous posters are more relevant.  I always recommend a slightly more conservative cam profile to take advantage of the low-rpm torque of a Pontiac.  One can go to 0.450" or so with stock springs so long as the RPM is below about 5500.  

oh ok now that makes sense with the heads. ive been searching ebay religiously for heads over the last month. the most logical ones that i have found are the 6x casting. and i took another look at the crack in the cylinder and i found that it is not just a crack but also a slight bulge. so what ive decided to do is go to the junkyard and find a 400/th400 and rebuild it. i wont put the trans in right away cause i want to do a little work to it first. i want to get the car moving under its own power so i can work out all the other kinks in it, before i go and build an expensive motor, depleting my budget, and have nothing left for cosmetic issues.

-matt  

Over the past 31 yrs. whenever I performed  a cam change I bought cam,lifters and springs(kit)this avoids just hoping that the valve springs will hold up(prevent valve float)Check installed height,replace keepers,valve stem seals,etc.  

Re-read all the posts and it seems you are definitly getting sound advice As Barney states there is a slew of info which needs to be evaluated before selecting a cam.Proper input will aid in selection-Remember a Poncho is NOT a Chevy
Many people cannot seem to understand this,and it can cost you time and money to learn the major differences in a build up between these 2 engine makes.Lifters can make a difference also if you go a litle wild-Rhoads lifters actually bleed down slightly at idle which alters valve timing Contact a reputable camshaft manuf when you have your info sorted out  After all it is your time and money