'71 Type 2 Engine knock before dying - FIXED! UPDATE 6-03-07

jblair630 · Post by **jblair630** » Sat May 05, 2007 10:36 am

Compression too high = hard start?

Today I am back on the case with Phred's rebuilt bus engine (1600 DP). The engine is back in the bus but I am not able to get a start to do the initial break in. When I have the spark plugs out to build oil pressure the engine cranks just fine. When I put the spark plugs back in to start, then the engine cranks very slowly and will not catch. I have double and triple checked the timing (statically) and made sure the valves were adjusted properly...

Back outside for a bit..

satchmo · Post by **satchmo** » Sat May 05, 2007 10:09 pm

I think this sounds like your battery is out of juice. Trickle charge it overnight or jump it from another car. Before you do that, double check your plug wires, and triple check that your distributor drive gear is in the correct orientation. I had similar problems on another engine where some one had installed the dist. drive gear 180 degrees off.

Good luck, Tim

texabus · Post by **texabus** » Wed May 16, 2007 6:15 am

Jeff,
Is she running or not?
David

zblair · Post by **zblair** » Wed May 16, 2007 7:24 am

Not running yet. Dropped the engine again last night to do another once over. The engine would turn over with the spark plugs out, but not with them in.

The battery was fine.

vwlover77 · Post by **vwlover77** » Wed May 16, 2007 9:09 am

I'm no expert, but this sure sounds like the valve timing is not set correctly (piston trying to suck in air or push out exhaust against closed valves), or the valves are not opening at all.

Did you put in a new camshaft? Who installed the gear onto the camshaft? Was it done correctly?

Have you put something (screwdriver, wooden dowel) in through the sparkplug hole to follow the piston motion while you slowly rotate the crank with a wrench and watch the valves open and close, and the position of the rotor? (Do you know what you should be seeing?)

Post by **Amskeptic** » Wed May 16, 2007 10:45 am

zblair wrote:Dropped the engine again last night to do another once over. The engine would turn over with the spark plugs out, but not with them in.

The battery was fine.

Errr, ahhhhh, starter? If the engine turns without mechanical drag with the plugs out, it is not the mechanicals. A fresh battery with slow cranking would then be like. . . the starter?
Colin?
(I need a Gulfstream)

jblair630 · Post by **jblair630** » Wed May 16, 2007 5:34 pm

I'm no expert, but this sure sounds like the valve timing is not set correctly (piston trying to suck in air or push out exhaust against closed valves), or the valves are not opening at all.

Did you put in a new camshaft? Who installed the gear onto the camshaft? Was it done correctly?

Have you put something (screwdriver, wooden dowel) in through the sparkplug hole to follow the piston motion while you slowly rotate the crank with a wrench and watch the valves open and close, and the position of the rotor? (Do you know what you should be seeing?)

I have been thinking along these same lines and have checked and checked again to make sure that I am at TDC on power stroke. Yeah, I know what to look for and all checks out. I have dropped the engine and am tearing it back down. Going back to the beginning and re-doing everything. I MUST have made a mistake somewhere but I can't for the life of me think of where. The only thing I can think of is to go back to square one.

Errr, ahhhhh, starter? If the engine turns without mechanical drag with the plugs out, it is not the mechanicals. A fresh battery with slow cranking would then be like. . . the starter?

Since you (on more than one occassion) and others have mentioned the starter, I am going to yank that out and give it a thorough inspection as well. I have to remember that learning sometimes is accompanied by frustration until the lightbulb goes on. "Be calm, young Skywalker, anger only leads to the dark side." (Yoda ducks as a 13mm wrench gets hurled in his direction)

Jeffrey

vwlover77 · Post by **vwlover77** » Wed May 16, 2007 6:33 pm

See if a local auto shop can test the starter for you...

texabus · Post by **texabus** » Wed May 16, 2007 7:19 pm

Jeff,
Don't tear it down yet. I'll come over tomorrow afternoon/evening and see what I can see.
David

jblair630 · Post by **jblair630** » Thu May 17, 2007 6:10 am

Thanks David. pm'd you

Jeffrey

jblair630 · Post by **jblair630** » Sun Jun 03, 2007 7:27 pm

First, thanks a million to David (aka texabus) for coming over to help with some diagnostics and advice. I had the motor out of the bus and mostly tore down by the time of his offer to help so when David came over we just went ahead and split the case. Number 4 bearing had walked off its dowel and had reseated itself in that “O” shaped cut-out on the bearing (I don’t remember the name of the cut-out but I believe it’s an oil channel). That wasn’t the big issue on why it wouldn’t turn over but between that and some other stuff, the engine would have led a very short life.

Went on a jag last weekend and put the motor back together, got it put back in the bus and still had a problem. When cranking to build up oil pressure, the engine would turn over just fine. When I put the spark plugs back in, it would turn over very slowly like the battery was very low. Had the battery and starter checked out and yes, the battery was low but the starter was good (thank goodness).

Z had suggested on several occasions (as did Satchmo earlier on this thread) to check the distributor; the distributor was 180* out but I had checked the orientation when doing the build and had moved the flywheel to watch the valves and I was sure that it was where it was supposed to be. Someone had suggested taking out the spark plugs, putting your finger over the hole and when you felt air being forced out of the cylinder then you were approaching TDC on the power stroke. Tried that and sure enough the distributor was 180* out. Go figure. So I reoriented the distributor, put the spark plugs back in, static timed and I’ll be damned if the thing didn’t start right up. I almost sat down and wept right there but instead I pulled the RPMs up to 2000 and let it run for about 20 mins for the initial break-in. I kept running back and forth checking for leaks and watching the oil pressure light but everything behaved itself. After the 20 mins I shut off the motor and drained the oil, lots of silver swirls but no flakes or chunks of metal which led to a big sigh of relief.

Did a final tune up today and drove around the block a couple of times to check for any unusual issues. I think Phred is good to go, finally!

Thanks to everyone for their patience and assistance.

vwlover77 · Post by **vwlover77** » Sun Jun 03, 2007 7:31 pm

CONGRATULATIONS!!!! Excellent news!

Hippie · Post by **Hippie** » Sun Jun 03, 2007 7:46 pm

=D> Good job!

Rob

Post by **Amskeptic** » Sun Jun 03, 2007 8:05 pm

The Long Road is often the best road. I'll bet you are pretty good at engine building now.

Colin

OB Bus · Post by **OB Bus** » Sun Jun 03, 2007 8:59 pm

My first and only rebuild was a long long time ago. Upon reinstall it would not start. Did everything that Lord Muir suggested. Finally found out that the dist cap had a tiny crack in it - probably banged it going in or out. $2 for a new Bosch cap and it fired right off.

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'71 Type 2 Engine knock before dying - FIXED! UPDATE 6-03-07

Update 5-05-07***

Final (hopefully) posting for this problem...6/3/07