Slow cranking 350....more details inside....

[mkast]

Re: Slow cranking 350....more details inside....

Check the firing order, mixed plug wires.
Static time the engine.

 

[KJSmitty]

Re: Slow cranking 350....more details inside....

- Get number one piston at top dead center - on compression stroke, then check distributor cap to rotor alignment on number one plug wire..

Double check distributor cap and plug wires to ensure 1-8-4-3-6-5-7-2 is actual between cap and spark plugs etc..

-And yes, that is the correct firing order for a GM 350.

With what you describe, you most definitely have a timing and/or firing order discrepancy.

Good luck

 

[petes penn]

Re: Slow cranking 350....more details inside....

So.........rechecked and reinstalled wires in correct fashion. Pulled distributor to ensure it was all there including old pump pin. All looked good. Replaced distributor and proceeded to crank. Lots of nice pops and pretty orange flames bursting out of the carb. Advanced distributor one way......more lovely orange flames.....had to snuff out the fire......advanced opposite direction......same thing but it really wanted to fire. This took a few trial and error sessions. Always have a fire extinguisher handy.....hint hint.....

Next we pulled the plugs and the acc belts to turn the crank pulley. Got out my breaker bar and a 5/8 deep socket. With my brother there, I began to apply pressure......bolt turned, and then the crank turned and the bolt then turned some more. Almost like it was slipping/stripping. This scared me so I backed off. Does anyone out there have an alternative to turning the crank? I am afraid I am going to break the bolt and then I'll have a whole new mess. We got the piston to the top of the cylinder by bumping the igniotion via key but not perfect. About 3/16" on the downstroke. At that position, the rotor was a little off the #1 wire.

I also noticed some marks on the block where the distributor whole is. There is also one on the distributor as well. Before we removed it we noted the position and reinstalled the same before trying to turn it over. Up front, there is a tab with degree marks on it. We are having trouble finding the respective mark on the crank.
This post is long and off the original topic so I may begin a new one with this info. Thanks again to all of you that have helped me.

 

[Bondo]

Re: Slow cranking 350....more details inside....

This scared me so I backed off. Does anyone out there have an alternative to turning the crank?

Ayuh,... Take the Sparkplugs Out.....

The mark somebody put by the dist. means Nothing....
It's the Rotor, Not the Dist that needs aligning...

You need to clean things up,+ Find TDC.....
Then install the Dist. with the Rotor pointing at #1......

 

[mkast]

Re: Slow cranking 350....more details inside....

I actually ran into this.
Told the charter boat capt. to point the distributor rotor to #1 cylinder.
When I got there, the rotor WAS pointing at the #1 cylinder, on the cylinder head, not the #1 cylinder plug wire on the distributor cap.

 

[petes penn]

Re: Slow cranking 350....more details inside....

We did remove the plugs....thought it would make things a little smoother....still felt that screw move more than it should. Cant turn it by hand which is why I asked if anyone had an alternative method. I thought one of those rubber locking straps might do the trick if I can find one that large

 

[littlebookworm]

Re: Slow cranking 350....more details inside....

Hi, Listen to Bond-o; he's got it right. It sounds like you may have the distributor off by 180 degrees, which is why you can't see any marks on the crankshaft harmonic balance. Have someone tap the switch while you keep an eye on the balance until you see the marks. Then sand them clean and mark the zero point with white paint. Then line that up with the timing marker and check your distributor rotor. That shold do it. Good luck. Hy

 

[KJSmitty]

Re: Slow cranking 350....more details inside....

Using the starter is fine - I prefer the plugs in (besides number one plug of course). Plugs in allows you to bump the engine over without it rotating more than you want.


Now, if you aligned the "distributor" to the marks on the block as you described that is a good thing because that most likely is the right distributor orientation facilitating plug wire runs not to mention the vacuum advance diaphragm location etc.. But as bond-o mentioned that is only part of getting the rotor in the right place.

As for TDC on the #1 compression stroke. Stick a finger in the hole, bump engine over until you feel the compression (air forcing upon finger etc.). The piston is now coming up on the compression stroke thus remove your finger and focus on the timing marks (both metal tag and the line on the harmonic balancer). Continue bumping until you get as close to lining up the line/grove on the harmonic balancer to the "0" on the tag etc. DONT GO TOO FAR..
Stop, you are now as close to TDC as you can get. Back to the distributor.

Two things you can do here, but below is the easiest....
1. Line the cap up with the current rotor position and "re-run" your wires on the cap so the #1 wire and firing order begins with this new rotor position. Tighten everything up and continue.


Begin to attempt start....

 

[Uraijit]

Re: Slow cranking 350....more details inside....

Yup, it doesn't matter where your distributor is pointing, unless you have the rotor pointing the right direction. Any one of the plug wires can be your number 1 plug, as long as the rotor is pointing there with #1 at TDC. Just get the rest of the firing order right after that, and you're good to go.

Ideally, the rotor should be pointing toward the #1 cylinder at TDC. Makes it easier to remember, when it comes time to replace wires, etc. You can also mark the cap with where your #1 plug should be, for future reference.

Your symptons sound almost identical to mine, when I had the distributor 180 degrees out.

 

[petes penn]

Re: Slow cranking 350....more details inside....

OK so we re-aligned the distributor with the marks on the block. We removed plug #1 and bumped the starter until the piston was atthe top of its compression stroke. We then checked the timing tab on the front of the block and the score in the harmonic balancer. They met at 0. then we pulled the cap to check the rotor position. It was pointing to the number one plug wire.....as close as we could get it. This took several attempts but it got done. Next we attempted to start the motor. It reacted the same as before but almost wanted to start. At thi point we thought we'd poor a VERY small amount of fresh fule into the carb.....I know,,,,Bad idea. Well, it really wanted to get going but my New battery was starting to drop below 12V.....11.5ish. I decided the throw the charger on it to bring it back up to full charge. This is as far as we have gotten.

With fresh fuel, it turned over but we still got a few intermittent flames. Nothing to big but enough to want to snuff it out. Is it possible that the gas in the boat is bad? It does not smell bad but what do I know. Just wondering if I should bypass the tank and attempt to start it with a jerry can. What do you all think?

 

[JustJason]

Re: Slow cranking 350....more details inside....

have you done a compression check on this motor yet? if you haven't.... i'd start there.

 

[hard-3]

Re: Slow cranking 350....more details inside....

leave distributer loose enough to turn while cranking to see if you are close to getting it to fire. i see you changed the module in the distributer , is it installed correctly?

 

[petes penn]

Re: Slow cranking 350....more details inside....

HEhehehehehehe......I have to laugh about this to hide my rage.....

Did a compression test.......Not one cylinder is above 90 PSI, and some as low as 65 PSI. Well, I know what that means.....Junk motor. Repowering is not in my budget. Nor do I have the capability to rebuild it myself. I suppose it would make a great mooring anchor right?

Craigslist is not the place to trust people. Seller insisted boat runs. Well, my "hired" marine mechanic says that is impossible, especially with only 65lbs in a couple of cylinders.

This has taught me a valuable lesson.....boating is expensive and if its to good to be true, then run away. This experience has tainted my desire to get out on the water.

Are there any monster truck shows soon? I think they would love to drive one of those trucks through this thing..........

 

[Maclin]

Re: Slow cranking 350....more details inside....

Do a leakdown/listen test to learn if it is just the valves or head gasket needing attention. If the test shows mostly exhaust or intake valves leaking then a quickie head refresh might get you a few smiles out of the boat before you decide to junk the engine. Now if the leakdown test shows major piston/ring blowby then a head refresh would probably not be worth it.

 

[Bondo]

Re: Slow cranking 350....more details inside....

This experience has tainted my desire to get out on the water.

Ayuh,.... I'm Sorry to hear that.....

Time on the Water is worth an Awful lot of aggravation.......

 

[JustJason]

Re: Slow cranking 350....more details inside....

If the test shows mostly exhaust or intake valves leaking then a quickie head refresh might get you a few smiles out of the boat before you decide to junk the engine

agree'd

it may be worth pulling the valve covers as well and make sure all the rockers are seated. and crank it and look for any sticking valves as well.
I do work in the newbury area from time to time. whose your mechanic? Private or shop?

 

[KJSmitty]

Re: Slow cranking 350....more details inside....

Well that truly stinks....

I agree with those above however. Being that low one would suspect (or at least hope for a valve/head issue..

Sorry for your discovery.

 

[petes penn]

Re: Slow cranking 350....more details inside....

Yes, it is disappointing, and I let the seller know how I feel.

My mechanic is my brother, certified and able to tear down everything from your weedwacker motor to an M1 Tank. I do have another local guy that is private and has worked on a friends boat for over a decade. He is coming over tomarrow for a bit to see what I am talking about. From my description over the phone, he agrees that if upstairs is an issue, then most likely there has been some damage downstairs. I guees this was Supposed to have a chrysler engine in it. But I have a GM......

I have heard that truck engines can be used as long as the engine has been marinized i.e. marine carb, diastributor, flame arrest, etc. I priced a late model 350 and it comes in around $300-350. This is coming from a friend that I deal with on a regular basis. Oldtimer with a junk yard. I dabble in the classic car biz and have build a repor with him over the years. He is excited that some "young blood" has some appreciation for the oldies. He's 60ish and I am 34.

So all that being said, I guess I am in for a wait as my bank account and g-friend are not happy right now.

 

[seaman69]

Re: Slow cranking 350....more details inside....

I just went through the same thing you are experiencing on a 455 olds jet drive. My solution was exactly what they describe. Remove plugs, line up top dead center, make sure that you allow for the twist in the dist., whoever tried to get mine running before me, missed that, so I reset the Dist. and was able to get it to run enough to get a timing light on it and further fix the problem. Runs like a charm now. I Also had a problem with the cranking, partly due to a low crank amp battery and timing, same thing, huge backfires, even blew off one of my flaps! so, it sounds like you have the power issue fixed, so I would focus on the timing. I have used a variable speed drill and a socket if you have clearance to turn the crank.