Just built a 302 roller motor carbed with a hei distributor.the cam i used was a trick flow stage 1 for a 351 but was told it would work in a 302 and to just use the fireing order for the 351. The engine started with no problem at all but the engine is fireing only on every other cylinder on the distributor rotation.tried the 302 fireing order and motor would only back fire so went back to 351 fireibg order.have checked compression on all cylinders and was all between 90 & 120 on all.no vacuum problems.wondering if cam is wrong ??? I also used factory push rods.any ideas?????
That's a big jump from 90 -120 in compression. I'd check them again. If it's the same. I believe there's something wrong there.
Welcome aboard! Question for ya...you say it started okay but it's missing on every other cylinder. I can't imagine it starting okay if it's only firing on 4 cylinders. I may be wrong but it's sounding to me like you may only have a couple wires crossed. Can you tell us the firing order you are using? The 302 firing order you tried should have been 15426378 but if you're using the 351 cam, I'm sure you'll have to use the firing order to go with it. I may be mistaken but I think the 351 order is 13726548.
Welcome from AZ I agree with Don I would do a compression check again, them numbers are a little too wide spread for me. And also if your running a 5.0 roller motor with a 351 windsor camshaft the firing orders are exactly the same between them too camshafts. http://www.302w.com/Firing-Order.aspx I would also recomend getting a pushrod length checker and measuring the needed length pushrod VS using stock replacement length. Any time you change a camshaft you need to degree the cam and check your needed pushrod length. This could be your compression problem :-/
