1974 D300 360 fresh rebuild will not start

[PlantJesus]

Well fellas.... 60 PSI still. 70 with the throttle plates open... Was the carbon on my pistons the only thing making a proper seal before I took this all apart??

Also, adding a hefty table spoon of oil raised compression by 30 psi. Soooo.... Also, this engine has been rebuilt before, so it's already at its max bore :/

 

[67Dart273]

Repeat have you tried some oil in the cylinders?

You sure the compression gauge actually works?

You visually checked valve operation?

Leak down test?

Hell I just noticed where you are. If my ribs weren't broke, I could'a driven down there by now LOL

 

[George Jets]

Well fellas.... 60 PSI still. 70 with the throttle plates open... Was the carbon on my pistons the only thing making a proper seal before I took this all apart??

OK

Did you change the camshaft on this last teardown or is it the same one as before?

Also are you using the same push rods as before or are they new ones?

 

[PlantJesus]

OK

Did you change the camshaft on this last teardown or is it the same one as before?

Also are you using the same push rods as before or are they new ones?

Same camshaft, same push rods (yes assembled back in the proper order). I bought this truck after it had been sitting for 13 years, printing on the bearings said manufacture date 1999, so it was only run for two or three years after the rebuild before it became basically yard art at a welding shop.

 

[George Jets]

OK let's go over where you are at now with the.compression. I am pretty sure of what is going on here.

70 psi on compression test with throttle plates open, that is better. Now you added 1 tbsp of oil to each cylinder and the compression came up another 30 psi to 100 psi per cylinder.

Is this correct ?

 

[George Jets]

Being the engine has not been started yet, did you prime the oil system with a drill by pulling the distributor out ?

By priming the oil system and having someone slowly crank over the engine by hand (with the spark plugs out . . easier) you are filling all of the internal oil passages and you are "Pumping Up the Lifters" at the same time. But need to rotate the crank and cam to fill the lifters.

Guessing the lifters are not pumped up yet only opening the valves partially on your compression tests.

More to come yet after you get back to us on the above questions.

Getting close to getting it fired up pretty soon here.

 

[George Jets]

I also have a '76 Truck that is up and running now just this Summer.

We are all working here to get your Truck up and running too. Getting Close . . .

 

[67Dart273]

The old piston stop I made in the early '70s...........

Remove battery ground, remove no1 plug, make sure piston is "down a ways." Install stop. Wrench engine around until rotaton stops against device. Make accurate, temporary mark onto balancer below TDC. Repeat after rotating against stop going CCW. Now you have two temporary marks, true TDC will be halfway between

Breaker points ignition:

Remove no1, stick in finger, bump until compression

Rotate engine not to TDC but rather, say, 10BTC

Connect test lamp to coil NEG. Rotate dist CW (retard). With ignition in "run" slowly rotate dist CCW (advanced) until light just comes on. This is the firing point. Snug down dist. Remove cap, make sure rotor is "coming to" the no1 tower.

Make sure plugs are dry, try a little fresh fuel in the carb throats, see if it fires.

 

[PlantJesus]

I also have a '76 Truck that is up and running now just this Summer.

View attachment 1715588282

We are all working here to get your Truck up and running too. Getting Close . . .

Yours is looking way nicer than mine... Full blow work beast here. I ain't giving up, too much invested in this old girl Thanks a ton, 67Dart for chatting with me and giving me more hints and tricks. I hope your ribs heal up quickly!!

 

[George Jets]

View attachment 1715588330
Yours is looking way nicer than mine... Full blow work beast here. I ain't giving up, too much invested in this old girl Thanks a ton, 67Dart for chatting with me and giving me more hints and tricks. I hope your ribs heal up quickly!!

Looks like a 1 Ton Dually, 2 wheel drive, 4 spd. with the flatbed.

360 engine, did it have the 2 barrel carb and factory 2 barrel intake manifold on it when you first got it ?

Wonder if it is still the factory 2 barrel cam and lifters on it yet too?

 

[67Dart273]

So, is it runnin?

 

[PlantJesus]

So, is it runnin?

Negative When I tested the spark yesterday, I sure didn't see a fat blue one, just a snapping noise. Albeit, it was very bright outside, midday.... Taking down some trees today and tomorrow, so I can barely make my wrists work to type. Wife is getting her motorcycle license this weekend so I have some time to stew on things. I'll keep ya updated. You will be the freakin first to know if it gets running.

Electrical. I've memorized the entire electrical diagram with how many times I've gone through it. New ballast resistor, new ICU, new ignition, bypassed the firewall connections for ignition. Doing all this DID increase the cranking (ignition 2) from about 6 volts to the coil, now it's up to about 9.8 but seems to be inconsistent, or I've had another electrical gauge go wonky on me.

 

[PlantJesus]

Looks like a 1 Ton Dually, 2 wheel drive, 4 spd. with the flatbed.

360 engine, did it have the 2 barrel carb and factory 2 barrel intake manifold on it when you first got it ?

Wonder if it is still the factory 2 barrel cam and lifters on it yet too?

Sorta 1 ton. Owned by a welder, there's some serious beef for suspension. She's had a lot more than 1 ton in her . I did replace the original 2 barrel carb and intake manifold, I did not even know I would need a new cam/lifters. When I did research on cams it seemed like they were for much higher RPM vehicles than mine as far as where they make power. Divulge your knowledge, please!

 

[George Jets]

Sorta 1 ton. Owned by a welder, there's some serious beef for suspension. She's had a lot more than 1 ton in her . I did replace the original 2 barrel carb and intake manifold, I did not even know I would need a new cam/lifters. When I did research on cams it seemed like they were for much higher RPM vehicles than mine as far as where they make power. Divulge your knowledge, please!

It's OK to run your 4 bbl on a 2 bbl cam. Like you say the truck engines were set up for low end torque, 4 bbl is just giving it a little more fuel and air that it can handle with the 2 bbl cam.

Just helps me understand your engine build knowing this.

 

[George Jets]

That spark snaping sound, sounds like the coil lead jumping to ground or jumping between cylinders at the top of the distributor cap.

Have your wife turn it over at night with the hood open and see if you can see where that loud spark is jumping at in the dark, this could be why it does not start.

So it looks like it is down to faulty spark to figure out and it will run.

Too bad you don't have access to a simple small block points distributor, one hot wire to the coil and it is running. Distributor lead to negative side of the coil.

When running need to make sure it is full of coolant and oil and let it run for a couple hours at a fast idle so that your new rings start to break into those smooth cylinder walls, that is the last bit why your compression is low . . rings need to get broke in.

Keep an eye on the engine temp as it is running, don't want it overheating on you at first run up.

 

[67Dart273]

I would temporarily jumper 12V right to the coil and see what that does for a difference. Don't leave that hooked up for long not running, tho...............