Low down: 1969 firebird, 1bbl. Engine ran fine prior to some disassembly, but had a crashed intake/exhaust gasket and water pump was toast. I wasn't going to do this right away, but I have another child coming in a few weeks and won't get much enjoyment out of the car for a few more years anyhow. I plan on a rebuild in hopes to restore eventually. currently have a 3spd floor shift and unknown rear axle as paint buildup over the prior years is making it quite difficult to find the code (where should i be looking? wire wheeling?)
Plan: engine overhaul using whatever I will need to bring it back to a tight sealed up unit. Kanter and Egge seem to be the top in rebuild parts. I would like to get the Clifford intake/exhaust setup with the Weber or Holly carb. I do have a sprint 4bbl intake in the attic as well i almost forgot about.
With intake/exhaust removed already, I decided to do a compression test and got a range of 130-160psi over 5 rotations on each cylinder.
Unknowns: cam, what would I benefit from most? Head, keep the 250 head and refurbish it? Or find a 230 head and do the same?
I would like to do as much of the work that I can and am fairly skilled. I know machine work will be hired out. I love learning and this will be my first car engine tackled. If anybody has any insight or advice, I'm still gathering info and trying to figure things out, but my email is mitchn06@gmail.com and I can be directly contacted at 6058600024. I am located in Sioux Falls South Dakota.
reading through a few forums, i'm having a hard time decifering if the valve stems need to be "tipped" or not. from my understanding the lash adjusters will compensate for it, so that the followers do not make contact with the spring retainers. So basically the new valves need to be "seated" into the head, with no other technical machine work to be done? next question. how do I obtain 4bbl spring tension on my 1bbl head? is there a spring that is readily available from another application that will slip right in? I know that the 4bbl has inner/outer springs, but i'm not sure how to tell what their combined rate would be. i see that the 1bbl rates are 165-175 @1.233" and 94-100 @ 1.663. I am asking this due to the E or H cam i plan on using with the build.
Yes you need to be very careful about the height of the valve stems above the head. If they are too high the followers will ride the Cam the whole time, preventing the valves from closing and wasting the cam. If they are too low, the follower will run into the spring retainer also resulting in significant damage. Check the Cammer web page and you will see lots of discussion on this topic. Also remember, each of these cammers have different valves so make absolutely sure you get the correct valves for your head. BTW, the valves are getting harder and harder to find. I highly recommend you contact Jerry Woodland and order parts from him (he is very reasonable) plus he knows what he is talking about. If you order from Jerry he includes a very good discussion about the head and what you need to do. If you have a 66 or 67 head, you need to verify the orifice in the head because the earlier heads had too large of a hole resulting in the lashes pumping up too much and wasting the cam. Do not preload the lashers, but rather run the oil pump (in place) with a drill in several locations to set the followers, if you don't you risk wasting the cam. As far as springs I would have you machine shop check them, unless they are broken, they might be OK. For the followers, make sure they are reground (if reusing) or make sure the surface on the new ones is acceptable. There are many horror stories about replacement follower seating surfaces being too course. I just rebuilt my Sprint and ended up regrounding both my cam and followers. Find a reputable machine shop AND assume they have never seen one of these engines because they probably never have. Research the rebuild carefully and bring the machine shop literature about all these specs. If they don't want to listen, get another machine shop. The bottom end is pretty standard, but be very very careful about the head.
Didn't mean to scare you and if you do your research you will be fine. Just completed my rebuild and everything is fine. Lastly, always use a ZDDP additive for your oil, both now and after rebuild.
Hi mitchn06, to answer your question on rear end ID. The code can be found on the back and center of the left axle tube. There may also be one on the left backing plate but I find a little wire wheeling on the back of the left tube easier.