we swapped a comp xtreem cam in a few weeks ago and just got the engine back in and everything bolted up today. we tried to start it but no luck. it makes a big chugging noise from the exhaust and after a while it shot flames out. i was playing with the timing but it did not work. too far advanced you get a fireball out the exhaust too far retarded and you get one out of the carb... could it just be valve lash? i didnt set it because it had already gotten dark out i just backed the nuts out so it was loose that way the valves wouldnt hang open. i really dont think that would keep it from starting though.

 

Try lashing the valves to start.

 

I was gonna do that today just wanted to see if thier was anything else i could doo. i had the valve lash so tight on my other motor that the valves wher haning open and it still started just didnt run well.

 

u need to get a book or something to read how to set ur valve rgt. i do it by going to tdc on each cylinder and set no lash and a half around more

 

Also double check that you don't have your distributor 180

 

Yea, thats what it sounds like to me. I'd just turn it 180 and try again. Bet it fires.

 

thats what i found out it was. i was trying to do valve lash and one of the valves that i was trying to tighten was open so figured it was 180. i flipped a few wires around and boom she cranks and sounds like a beast... thanx for the help so far i have swapped an engine from a 305tbi to a 355 carb then took it out and did heads cam and exhaust all with info i found on this site.

 

nice to see the problem is fixed.. once, i put in my distributor one tooth advanced.. would barely turn over.. it would turn, then stop and spin the other way.. i thought i bent some valves or something.. turns out the timing was at 75* advanced and it was firing on the compression stroke..

 

Somethings wrong if it DOESNT fire on the compression stroke

I know what you meant though... Too much advance will cause it to kick back

 

Common problem when doing a cam swap. Instructions say to line the dots up on the timing gears when installing the chain. Instructions don't say that this puts #1 cylinder at TDC on the exhaust stroke. When #1 is at TDC on the compression stroke, the dot on the cam gear needs to be at the top.

 

so its not my dizzy that was 180deg out it was my cam? i put the cam in the same way it came out the dot was on the bottom. is that gonna cause any problems?

 

No, it was the distributor.

When the cam and crank gear are dot to dot, both #1 and #6 are TDC, but the cam is in #6 firing position. The distributor has to be installed with the rotor pointing to the #6 terminal.

 

that scared me for a sec...
thanx for the info guys