supersonicvette

Hello all, so I'm at my wits end trying to start a rebuild engine I just purchased form a machine company. I have set it to TDC on the compression stroke at least a half dozen times (Using a finger over the hole as well as an inspection camera in the #1 cylinder spark plug hole), installed and tried two different distributors to cylinder #1 but nothing. All the wires were in the right order, plugs are getting juice but i'm only getting a sputter every once in a blue moon. Needless to say it is getting gas and air so I'm stumped.
I know it's hard trying to diagnose this without actually being here but any help or hints are appreciated.

GOSFAST

Could be number of any possibilities it won't fire, wouldn't know where to begin from here???

I just hope for your sake it's a roller cam build and not a flat-tappet??

Thanks, Gary in N.Y.

P.S. If it IS a flat-tappet I wouldn't even crank it one more time until you resolve the issue!! It may already be too late, hope not!!

sullyman56

Before I did the initial start on my BB I verified that the rotor was pointing at the tower for the number 1 plug and that the timing mark was slightly BTDC. Doing it by myself without a remote starter I used a small piece of paper towel in the number 1 spark plug hole and cranked the engine until it popped out. Once I installed the plugs and wires it fired right up. Hopefully, your issue is something simple.

NeverTooOld

1. Make sure it's on TDC of the COMPRESSION stroke

2. After you feel pressure blowing out of the #1 spark plug hole the engine still has to turn over another 90+ degrees before it hits TDC of that compression stroke

3..Verify the rotor is pointing at the #1 spark plug wire terminal

4. Once it starts bring the engine speed up to 2000+ rpm and keep it there for 30 minutes to break the cam in. If the cam is a hot cam that uses inner and outer springs (the damper spring isn't considered a spring) never break it in with that inner spring installed or you will risk wiping the cam out. Adjust the timing to show about 45 degrees of advance while the engine is running at that 2000+ rpm. Do NOT idle it during that 30 minutes.

HeadsU.P.

STOP! Before you ruin some lobes, bearings, etc. You're getting a sputter that means you are close on the timing. But. I would highly recommend purchasing a oil pump primer shaft and install it in place of the distributor. Pull drivers side valve cover. Run primer shaft with H.D. electric drill to verify you have oil pressure at the rockerarms. Now rotate engine by jogging the Ign key and watch the #1 EXH valve close, then INT valve open, & close. Monitor your timing mark / pointer to zero. Continue priming. Remove shaft, install dizzy pointing at #1 cyl, replace valve cover. You should be good to go. A little shot of gas down the carb, throttle adjustment set high. Total timing should be around 34 for now.

blue427

before you ruin the new engine,change the oil and filter as you've probably was the cylinder walls and everything else down with gas.Next,pull the dizzy and turn your oil pump till you have good pressure.When you reinstall the dizzy do not,I repeat set it up on tdc,put it in so you are 8 or 10 degrees advanced,it will not start at 0 degrees.Once you start it and it will start rev to 2000rpm and go to 2500rpm,then go up and down in that range,do not hold it at a steady rpm.Do that for about 30 minutes.That is what Comp cams recommends(last time I checked,go on their web site to verify).You can set your timing up later.Also I would pull the rocker covers off and put my oil in from there,don't forget to fill your oil filter before you install it on the engine.

IronMaidens2.0

Did I miss it or did u post what year ,Carb or FI ?

Buccaneer

You haven't replied yet to the question if this is a flat tappet cam or roller. I'm hoping as well for your sake that this is a roller cam or you may have already caused damage to the cam. If flat tappet...STOP! Find the issue and correct before doing anything else.

Also, you did not mention if this was old school distributor or a HEI and computer controlled motor, which would be great to know which one. What year vette are we talking about?

If it's an HEI computer controlled car and you can laptop tune it, here is what I do with all my motors with no issues and they all fire right up and timing will be very close. If you know what your Initial timing is in your tune, which in my case is 20*BTDC in my tune for my 383. I bring #1 up almost to TDC, but stop it at 20* on the balancer (this is very easy to do with the bellhousing cover off and my flex plate tooth tool to rotate the motor by hand, you can bump it with starter as well and stop when close and do it by hand a few degrees on crank bolt also) Now you're ready to fire it up, drop the distributor in with the rotor pointing at #1 on cap where ever that may be and you should be good to go. (substitute 20* with my motor to what have for your initial)

If old school, just bring #1 up to TDC and drop the distributor in same as above. Hope you find out what is going on with your motor before any damage occurs.

stumpshot

Pull the drivers side valve cover. Turn the engine till the #1 intake and exhaust are closed and no movement of those valves occurs. Look at the balancer. Is the timing mark on TDC? Is dist pointing dead at #1 plug? If yes to all these, check the lifters---maybe they are too tight and holding the valves open.
Let us know what you find.
Oh, if the balancer doesn't set on zero with #1 valves closed the cam may be installed wrong.

Scottd

While many guys here are very correct about wiping cams and doing damage, I feel your solution is just a matter of timing. I dont want to downplay their advice, I just want to make it sound a little less drastic.

Get a helper to crank the engine. As they are cranking, turn the dizzy counterclockwise. After about an inch or so of turning, Im betting it fires up.

I went thru the same thing. I installed a new roller cam and couldnt get it to fire. I called my neighbors 10 year old over and instructed him what to do. (He was excited to help bring the car back to life) After about 5 seconds of cranking and me turning, it fired up.

Buccaneer

Where's the OP?

supersonicvette

The engine is a late 70's 454 bored out to a 496, it has been set to 12° before to dead center on the compression stroke each time, has a HEI distributor getting 12+ volts at run and 10+ during cranking. Engine has also been primed with oil using a drill between each failed attempt.

HeadsU.P.

Now we might be on the right track. You say you are pulling the dizzy out after each starting attempt? Do you feel confident that the dizzy is not 180* out? Without watching the #1 valve actions because the valve cover is on, it could happen. And you would get a firing sputter off of a different cyl than number 1.

sullyman56

CanadaGrant

How do you know you are setting it at 12 degrees advance if it hasn't run yet? I agree with the above posts that you are probably 180 out on the distributor rotor.

supersonicvette

I've been putting it in with the drivers side valve cover off. I've also bumped it over with my finger over the spark plug hole until I felt it blow off.

Buccaneer

Is it a flat tappet or roller cam?

supersonicvette

It came with a Elgin industries E1143P hydraulic lifters grind cam and hydraulic lifters if that helps.

derekderek

a little more detail on 180 out. bump engine til you see exhaust just closing and intake just opening on number 1. check timing mark. at this point you are firing on number 6. put distrib in pointing to 6 instead of 1. now you are SURE which way is up...Googled your cam. hyd flat tappet. 306 advert duration. 254 at .050. 576 lift, 110 lobe sep. this is not a daily driver cam. beastie is rather radical. not the kind of lift that requires 450 lbs of spring, which REALLY shortens valvetrain life, but idle to 3000 rpm will be somewhat suboptimal.

HeadsU.P.

Inspection camera you mentioned only reveals where the piston is in the cyl. It does not reveal which of the two TDC strokes its on. I still suspect you are intalling / pointing the dizzy on the wrong cycle.

#1 Exhaust valve on the drivers side is closest to the radiator. When it closes, watch for the Intake to open / close. Keep jogging the Ign key. Bring the harmonic balancer around until the marks line up TDC. Drop in dizzy, cross fingers.
One other thing. The oil pump driveshaft make give you grief when installing the dizzy. Take a really long screwdriver to align the slot in the shaft with the dizzy.
Be carefull about letting the dizzy drop in place when jogging the IGN key. You could be off by one tooth. That could be your issue.