New engine, won't run!

[brothers69c-10]

Exhaust currently is open headers.

The ignition system is a known good one. It came right off the motor that came out of the truck. That motor ran until i took it out and put the new one in.

[combustion]

do you have compression? does it sound like it cranks over loose? did you install the spark plugs wires counting clockwise or counterclockwise on the distributor? try adding fuel directly into the manifold to eliminate it being the issue. do all chevy engines spin the distributors the same way? are your points fully breaking and closing properly? is your module jacked up if you are running hei? cant be that many things

[brothers69c-10]

Originally Posted by combustion

do you have compression? does it sound like it cranks over loose? did you install the spark plugs wires counting clockwise or counterclockwise on the distributor? try adding fuel directly into the manifold to eliminate it being the issue. do all chevy engines spin the distributors the same way? are your points fully breaking and closing properly? is your module jacked up if you are running hei? cant be that many things

Sounds like someone needs to read through other posts before posting their 2 cents worth.

[D13]

OK, Here's my confession and something to check.

Check that the plug wires are in firing order going the correct way around the cap. Set it to #1, remove the cap, roate 1/4 turn, and see what plug wire the rotor is pointing to. Then make sure that matches the firing order.

I've sequenced the the entire distributor backwards before. It would hit on #1 and sort of on a couple others but would not run. The more fuel the worst problem as the plugs got a bath.

Compresson check? Rockers adjusted and not holding the valves open (ie lifters pumped up)? Suck squeeze bang blow - need valves for 3 of the 4.

Or, fuel, air, and spark. Ether should have taken care of the fuel unless the carb is dumping fuel down the intake.

[russgt]

Any signs of gas in your oil? After cranking it for a little while do you notice gas coming out of the collectors?

[combustion]

Originally Posted by brothers69c-10

Sounds like someone needs to read through other posts before posting their 2 cents worth.

if you had compression, right firing order, fuel, cam timing and ign timing right i bet you it would run. you are obviously missing one of them. no pun intended.

[britnjc]

any updates?

[leegrady]

Compression

Spark at the right time

Fuel

With these you are well on your way.

My two cents is: the base timing is off, and possibly no or low compression in one or more cylinders.

Set #1 at tdc of the compression stroke. Crank the engine over with #1 spark plug out, and your finger over the hole, and stop cranking when you feel air being push out. Now your in the ball park turn the crank manually until the mark on the harmonic balancer points right at zero ("0") degrees on the scale. (Remember that the crankshaft to camshaft ratio is: 2:1, so that mark will also point at the scale 180 opposite the compression stroke.) So, again, #1 at tdc compression stroke, both intake and exhaust valves closed, and next be sure the rotor in the distributor is pointed at #1 spark plug wire. If I'm not mistaken that distributor shaft will only go two ways: correct, and 180 degrees off. You don't need to remove the timing cover to know the sprockets are installed correctly.

If I found a no, or low compression cylinder I'd perform a cylinder leak down test to determine if the lack of compression is caused by an intake valve not seating properly, or an exhaust valve not seating, or if the rings are not holding. You simply pump (low psi) compressed air into the cylinder by way of the spark plug hole, and listen for the tall tale hiss of air. Listen down the carb for intake, yep, the exhaust pipe for, you guess it, an exhaust valve that is not closed when it should be, and finally remove the oil filler cap on the valve cover and hear what you've been missing. A hiss here says: rings. Oh, yeah, this must be done with all the valves on the cylinder you're testing be on the flat of the cam, (closed) compression stroke of that cylinder.

I hope compression is not your problem. I want to write too not to be confused by ole wife's tales. Your problem will be obvious once you find it. On a personal note: that ole big block will at least run rough even if there is oil, wd-40, low octane gas, moose piss and beer contamination in the cylinders. Cold weather be damned. I get in my truck 81 GMC K2500 on some mornings up here in 25 degrees below zero, not wind chill factor, and it fires right up no problem. Sep' my coffee turns to slush before I open the door.
No, your problem is there, and you'll probably go, "of course!".

[Drzronnie]

I know nothing about this motor so this is a stab in the dark from my Mercedes background. Mercedes will often have starting problems all the way up to a no start due to horribly out of adjustment valves (recommended service ever 10K but I picked up a 76 300D that had never had it done, and the people were told it needed a motor). I know somebody had mentioned this earlier but I just thought I would throw in how bad the benz problem is thinking maybe it could be on this too. Hey man good luck, hope ya get it runnin'.

[PRattenbury]

Check your wiring to your starter? Run vs Start terminal? Get those mixed up it may fire in the start position but stop when key is released to run position.

[LeaveEmBehind]

this may sound stupid but may play a part. Does it crank over fast enough? ive had a few motors refuse to start because it didnt crank fast enough. Used to have to crank it at WOT to get it to run if not it would just spit n sputter, till 1 day it just refused to start ended up getting a high-performance starter (just spun faster) n solved my problem. i dont know why it needed to crank fast but did, had fine compression (190) fuel was fine and spark was fine, but stupid as it sounds that what it was, so if your compression is good and u feel timing is fine, maybe try cranking at wot or if it dont help maybe a better starter? Keep us posted as im very curious as is others to what your problem is.

[brothers69c-10]

Well to all of you wondering, i think i finally solved the problem. I poured oil down the cylinders 2 weeks ago and let it sit for about a week and went back, cranked the motor over for a while and left the plugs out for a few hours, the nput them back in and the stupid thing acutally fired on all 8 for about 5 seconds. Didn't backfire or nothing. So i pulled the plugs and they were all covered in oil and some wd40 that had been sprayed down the cylinders about 3 months ago prior to installing the engine. In other words there is som much oil residue in the cylinders that its causing the plugs to foul and lose spark, get the cylinders cleaned out and i think i will be in good shape.

[68 TT]

Originally Posted by brothers69c-10

Well to all of you wondering, i think i finally solved the problem. I poured oil down the cylinders 2 weeks ago and let it sit for about a week and went back, cranked the motor over for a while and left the plugs out for a few hours, the nput them back in and the stupid thing acutally fired on all 8 for about 5 seconds. Didn't backfire or nothing. So i pulled the plugs and they were all covered in oil and some wd40 that had been sprayed down the cylinders about 3 months ago prior to installing the engine. In other words there is som much oil residue in the cylinders that its causing the plugs to foul and lose spark, get the cylinders cleaned out and i think i will be in good shape.

Good to hear it fired up. If they are just oil fouled you can soak the plugs in mineral spirits to wash off the oil so they are usable again without having to replace them. Blow them dry with compressed air and you are good to go.

It should burn any excess oil out of the cylinders pretty quickly once clean plugs are in there.

[brothers69c-10]

Going out early in the morning to clean the plugs and try ro clean the cylinders out some more and see what happens

[brothers69c-10]

So cleaned up two sets of plugs and finally got it to where when ipull the plugs out now they actually smell like gas, but the darn thing still won't run. Might buy a third set of plugs, maybe the other ones were fouled one too many times? It will fire and act like it wants to take off, but just won't. On a side note i know the valves aren't too losse cause the motor turns over nice and smoothe, but there is a possibility of thembeing too tight(keeping a valve opened.) I was going to do a compression test, but i was doig something wrong and lost a sring for one ofthe release valves on the tester(sorry ryan), but with using my finger i checked each cylinder on the drivers side and they felt consistent. Going to get accurate compression readings hopefully this coming wekend and go from there cause i really want to drive this thing.

[ont_guy_38]

The plugs they make today don't like to be cleaned , they always seem to foul after that . I would try another new set

[brothers69c-10]

Ok so I've tried new spark plugs, rechecked the valves and adjusted the mtighter and looser to see if that did anything, Pulled the valve covers off and checked the valves to make sure the cam was in right, tried different carburators, pouring gas down the carb, differnt distributor cap again, checked timing again, has compression. At this point if i had the money i would just put a cummins in the old truck

[glock35ipsc]

But you still haven't pulled the timing cover to check the alignment of the sprockets, correct?

[brothers69c-10]

Shouldn't have to, pulled the valve covers, broguht number one cylinder up to top dead center and both valves on #1 and 6 were closed and the distributor was in the correct position.

[glock35ipsc]

Oooooooook.

[brothers69c-10]

Well i give up, I'm just going to pull the engine out, put new rings in it, a different cam and start all over. Also i'm going to build a stand to test fire it on so i don't have to put it back in the truck to see if it runs.

[Mayhem.Evol]

Well, goodluck with it man. keep us updated on it!

[billnorman]

Let me say this about that. I see by your list of other vehicles that you should have enough experience with old iron to get this thing running. When I was young, and I'm not, I would try and try and try and sometimes give up and get some old fart to help me. It always worked. I'd either have to repair something or get the verdict; "It's kaput and isn't gonna go", and give up. Wish I was your neighbor, I'd be over with a cold one just to accept the challenge of getting it going, but I'm not. I would bet some old fart that has been turning wrenches for 50 years can give you the verdict, or get it going, but at this point, you might as well forget it. Let us know what you find.

[Dieselwrencher]

He has had a few of the said old farts giving ideas and nothing is working. We/he have tried everything. I think the rings are just rusted or glazed from the engine sitting so dang long. This is my guess. we will try the new rings and install a cam that will fit his needs more accordingly and go from there.

[brothers69c-10]

To anybody still wondering, i finally got this engine running. I pulled it out and cleaned everything up. I installed all new bearings, rings, and a new hydraulic cam. I did all this within the last week and put the motor in yesterday and it fired right up for me. When i tore the engine down it had alot of sludge built up in it. The lubriplate that was used o asse,ble the motor had broken down. The cam didn't look bad, but i favor a hydraulic cam over a solid lifter one.