New Cam/heads and it wont start. Help!

[ihatericeburners]

Started with a goodwrench 350 and added a comp cams xe262 and stock vortec heads, with edelbrock manifold. I have an edelbrock 1406 carb with a rebuilt HEI, I did myself. I replaced the timing set. I have verified TDC with a piston stop and marked my balancer. I installed new hydraulic lifters from comp cams.

While attempting to first attempt to start the engine, I got a small backfire through the carb. The engine sounds like it wants to run but only starts to sputter slightly. I checked the orientation of my rotor, pointing to the number 1 plug on the cap. I rechecked that TDC matched the intake valve closing and by feeling the blowing of air out the plug hole. The valves were lashed using the jiggle up and down method and turning crank 90 degrees at a time. I primed the engine with the tool with the collar to get oil flow the galleries. She had plenty of oil pressure. Filled the bowls with fuel, and filled the line from the mechanical pump to the carb. There is fuel into the carb. Firing order has been triple checked. My battery has been verified with a load test and I have 12 volts to the Hei. I have the initial timing set to 10 degrees BTDC. Timing was verified by a timing light while engine was cranking. Therefore I must have spark to the plugs if the light was picking up the signal.

I am just stumped on what my issue is. I am open to any ideas on what to check next and possible solutions.

Thanks in advance!

[leftybass209]

Did you check that the cam was installed correctly? You can be exactly dead on with tdc, but if the cam and timing set wasn't in alignment, your exact symptoms will occur. If that is spot on and you know for sure it is, advance or retard your distributor. You've got nothing to lose because it already won't fire.

[Thorkle Rod]

You didn't say anything about if your plugs are actually putting out a good spark. I would suspect the coil or electronics of the HEI. I have received bad ones that were brand new and made my life very frustrating. Good luck

[firedemon]

sounds like too far advanced if its getting 10 degrees with only cranking engine when it starts it will be 50 degrees or better try playing with distributor

[ihatericeburners]

Originally Posted by leftybass209

Did you check that the cam was installed correctly? You can be exactly dead on with tdc, but if the cam and timing set wasn't in alignment, your exact symptoms will occur. If that is spot on and you know for sure it is, advance or retard your distributor. You've got nothing to lose because it already won't fire.

I installed the cam and timing set "dot to dot" Then I turned the engine over to get both at 12 o'clock. But then I had something tell me that timing was off when I was doing my valve lash. I verified TDC and found the timing mark on my balancer didn't match. I have turned the engine over many times now.

I tried playing with the timing too. Going from 0 to 20 degrees. I also have a flat tappet cam and don't want to run the risk of wiping the lube off my cam.

Thanks! I feel like its always best to talk these kind of things out.

[agawam]

If you put in a new timing set and lined up the timing marks so that they were crank gear up 12 oclock and cam gear a 6 oclock the engine will be set to fire no.6, with both time marks at 12 oclock then it fires no 1 if when you try to start and get a back fire you could be 180 off

[88Stanger]

I am sure you know that the piston will come up twice to the top, once for compression and once for exhaust. I have done the finger in the hole and waited for poff on the finger only to discover later that it was on the exhaust lift and we were 180 degrees out on timing, just trying to help. sometimes simple things can get us.

[ihatericeburners]

Originally Posted by 88Stanger

I am sure you know that the piston will come up twice to the top, once for compression and once for exhaust. I have done the finger in the hole and waited for poff on the finger only to discover later that it was on the exhaust lift and we were 180 degrees out on timing, just trying to help. sometimes simple things can get us.

This makes sense. I will have to investigate. I used the blow off method when the valve cover was on. So I have some doubt.

[ihatericeburners]

I verified 12 volts to the hei from the ignition. I pulled the distributor to start ruling stuff out. Anyone know of a goodwrite up testing tit with a multimeter? I found a few. But I NEED one simple for me to understand it better.

[ihatericeburners]

I am re- revivifying TDC. Has anyone used a spark plug piston stop tool and got a incorrect reading? maybe upward travel of the exhaust stroke?

[Daman]

I'm going to go with rockers may be too tight. Back them all off 1/4 turn. Then try restarting.

[Kennuck]

Originally Posted by 88Stanger

I am sure you know that the piston will come up twice to the top, once for compression and once for exhaust. I have done the finger in the hole and waited for poff on the finger only to discover later that it was on the exhaust lift and we were 180 degrees out on timing, just trying to help. sometimes simple things can get us.

x2
A finger in the plug hole is not a good way to determine TDC on compression stroke. You're likely 180 out, backfire through carb is classic symptom 180 out. Give it a try its easy to do and will likely fix your problem.

[cooperhw]

Sounds like 180* out to me. Pull the dist. bring up to tdc with your finger in hole it will push compression out. On exhaust stroke at tdc the exhaust valve is fully open. look inside the motor with a flash light and turn the oil pump so the dist. will drop where the rotor points towards #1 cylinder and the dist. has adjustment forwards and backwards.
Not saying it's perfect, just how I do it.

[Thorkle Rod]

Just curious if you have figured this out yet?

[GASoline71]

Originally Posted by Daman

I'm going to go with rockers may be too tight. Back them all off 1/4 turn. Then try restarting.

I was thinking the exact same thing.

Gary

[DWilbur]

I had the same problem and install the wires on the dissy backwards to the rotation. rewired it and fired right up.

[ihatericeburners]

Sadly I still have my problem. I tried the suggestions above and still nothing. Im at the point to just buy a new distributor and carb.

[NC_John]

Originally Posted by ihatericeburners

Sadly I still have my problem. I tried the suggestions above and still nothing. Im at the point to just buy a new distributor and carb.

The comp cam timing hieroglyphics for advanced, 0 degrees and retarded might have you messed up. I screwed up mine when I installed the timing set and it drove me crazy trying to figure out why it wouldn't fire. Finally dropped the pan and pulled the timing cover and sure enough, I had buggered it up.

[CC69Rat]

Just thinking out loud - starting from TDC

If you initially installed the cam and crank gears dot to dot then rotated around to get them both at 12 oclock, wouldn't #6 would be on the compression stroke at that point (?)

If the dist is dropped in pointing at #1 it would be way out. (Retarded / 180 out) as others have stated.

Maybe.. pull the dist back up and turn your oil pump gear so the dist will drop and the rotor points at #6 on the intake stroke. Just curious if it will fire.

I'm not following why Comp would suggest 6/12 oclock on the installation then rotate to 12/12 ? If I'm at TDC at 6/12 and rotate it then lining the dist up at #1 the traditional way kinda goes away .. the crank would rotate a full rotation for 1/2 the cam rotation.

[67 chevelle]

Originally Posted by cooperhw

Sounds like 180* out to me. Pull the dist. bring up to tdc with your finger in hole it will push compression out. On exhaust stroke at tdc the exhaust valve is fully open. look inside the motor with a flash light and turn the oil pump so the dist. will drop where the rotor points towards #1 cylinder and the dist. has adjustment forwards and backwards.
Not saying it's perfect, just how I do it.

my vote also , assuming engine was put together correctly

[cg285]

Originally Posted by ihatericeburners

I installed the cam and timing set "dot to dot" Then I turned the engine over to get both at 12 o'clock. But then I had something tell me that timing was off when I was doing my valve lash. I verified TDC and found the timing mark on my balancer didn't match. .

dot to dot or dot to zero

[cg285]

probably why the balancer didn't line up - wrong dots

[ihatericeburners]

The good news is she's alive!

the bad news is I still have issues. I belive they are with timing. I have been getting a backfire through the carb when I start it and I have to press the pedal to the floor to get it to start. So I have more work to do still.

thanks!

[ihatericeburners]

[IMG][/IMG]

[PGSigns]

Recheck the firing order to ensure they are all good. Now to verify a timing mark with a stop you insert the stop and turn the crank by hand till it touches. Put a mark on the balancer and rotate it back around till it touches. Put another mark. The spot in the middle is zero. Use this mark to align a timing tape. Then use the timing tape to see exactly what the timing is doing. That will help you get the initial timing correct and tell what the hei is doing as the rpm goes up. A timing curve that is out in left field will cause all kinds of issues. Now we need to talk about fuel pressure. Much more than about 4 psi at idle and 5 while running will make it unhappy.
Jimmy