New engine update

Joined: April 23rd, 2016, 11:23 am

August 13th, 2017, 1:38 am #1

As you know I've been working on the 23 Commander all summer and have finally made notable progress. Engine beds have been replaced and all glass repair in the bilge is done including the new shaft tube. Entire bilge bay is painted bright white.
New engine is complete and fired for the first time tonight. She fired right up with no issues, she ran just long enough to check timing and oil pressure. Tomorrow we hook up cooling and start break-in procedure. The new Edelbrock 1409 is awesome just like all the others that I have purchased, no tuning needed and awesome throttle response!I wish I could post pictures!
The sound of a brand new engine starting for the first time is better than sex!

Craig Wilson
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Paul
Paul

August 13th, 2017, 8:00 am #2

Good news ! I will say, If you can do all THAT, you can also post photos ! lol

Regards,
Paul
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Joined: April 23rd, 2016, 11:23 am

September 6th, 2017, 11:56 pm #3

Hi all,
I have about 4 hours on the new engine. She runs fantastic, I can't wait to get it in the boat and get out on the water.
I have encountered an interesting situation. While the engine starts and runs fantastic I have an interesting situation. The engine will not run unless the timing is set to aprox. 25-30 degrees BTDC.
I have tried all the things I know including changing distributor timing, I have checked cam timing and that checks out. I have swapped distributors, timing lights etc., etc., etc.
I don't understand how cam timing can be spot on and yet the engine will not run inside normal engine timing parameters.
I have checked with all the pros I know and tomorrow I will try to contact the engine supplier to pose these questions.
I've exhausted all the ideas I know from past experience, I've never seen this particular situation. I'm hoping someone here has seen this problem and knows hot to address it.


Craig Wilson
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Joined: July 15th, 2005, 8:09 pm

September 7th, 2017, 1:18 am #4

Are you timing off the new front flywheel pulley or the Chris-Craft dimple on the flywheel ??

That dimple on the flywheel is probably around 10-degrees BTDC when the motor is spinning around 500-rpm or so.

What kind of distributor are you using, mechanical, vacuum, electronic, HEI style, etc.?

What series is the motor.............is it an updated "Vortec vintage" or earlier ??

You may have answered all of this in previous postings but it's always good to clarify the basis for the discussion at the first posting in a thread so everyone knows what we're trying to troubleshoot

Regards,
Paul
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Joined: April 23rd, 2016, 11:23 am

September 7th, 2017, 11:07 am #5

Hi Paul, I knew you would be there for me.
I have been timing off the mark on the harmonic balancer but I have seen the dimple on the flywheel, it just won't run there.
I started with an aftermarket HEI distributor that has a mechanical tach drive. Just to see if that's where the problem was I replaced that distributor with a brand new ACCEL HEI distributor that I had on the shelf. Both are mechanical non-vacuum style.
Motor is pre-vortec style.

I have checked cam timing and TDC is spot-on the zero mark on the balancer.
I have pulled and reset the distributor multiple times checking the firing order each time.
I even went so far as to secure the flyweights under the cap to make sure I didn't have weak springs giving premature advance.
I contemplated the possibility that maybe the engine is not an opposite rotation engine but if that were the case it would only run 180 degrees off and that's just not the case. It only will run at a rock solid 30 degrees before.
I am hoping to find time to call the engine supplier today, maybe they have an answer.
Either way I'm stumped, I've never seen this before.

Craig Wilson
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Paul
Paul

September 7th, 2017, 1:44 pm #6


A tip I saw....

"See what the timing is when you rev the engine up enough that the timing won't advance any more (probably around 2000- 3000 rpm or so). Should be set to somewhere around 34 degrees on a 350 with older design heads, maybe a bit less for the modern heads."

Should be around 8-10 degrees at idle

Regards,
Paul
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Joined: April 23rd, 2016, 11:23 am

September 8th, 2017, 11:13 am #7

Well the timing at 2000-3000 rpm is so far off the scale it's only a guesstimate but it's probably 40-50 degrees.
Idle is 30. Engine supplier did not impress me with their lack of help. They are saying that the distributor is causing the problem, I certainly don't know everything but common sense tells me that this cannot be the case. That line of thinking does not explain why the engine runs at all at this extreme setting.
I keep thinking the cam is off a tooth even though the relationship between TDC and zero mark on the balancer seem correct.
I'm in uncharted waters here as I have never worked with an opposite rotation engine. I'm pretty sure of myself with automotive rotation and I'm trying to apply that knowledge to my current dilemma but I'm not coming up with the logical answers I thought I would.
I don't see where trying another distributor will be worth while since I have gotten the exact same results from two different brand new ones.
Any other thoughts before I pull the timing cover?

Craig Wilson
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Paul
Paul

September 8th, 2017, 2:49 pm #8

On the older style GM small block motors like the 327F, for instance, the distributors and distributor gear is the same on the standard rotation and the opposite rotation motor, so just about any GM distributor can be used for testing, and of course the marine units should be used for on the water running. The reverse and standard motor distributors spin the same direction. In 1986 that changed.

Always be sure you don't have a plug wire on the wrong plug.

If the valves are responding as they should to TDC, ans as you observe them while rotating the motor, then the cam should be on the right tooth.

Regards,
Paul
Last edited by FEfinaticP on September 8th, 2017, 5:09 pm, edited 1 time in total.
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Joined: April 23rd, 2016, 11:23 am

September 8th, 2017, 10:09 pm #9

So in your opinion what should I do next? I have to find and fix the problem but it stands now I'm stuck. I don't know what to do or how to do it.

Craig
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Paul
Paul

September 8th, 2017, 10:37 pm #10

I guess one thing I would do is to watch the distributor advance by watching the movement on the timing light, and then revving the motor to the point where the advance is "all in". That is normally, as you stated, in the 25 to 30 degree mark. Then I would back up about 30-degrees to the point where it should be TDC, and then move to a point where you are around 10-degrees before that mark. That, in the absence of good markings to time to on the graduated scale or dimple, should put you right about the same point you would normally be if you did get the proper reading on the dimple, while at idle.

If that is the same general location as the dimple, then you know you at least have a baseline to work with. From there, if that is not working, I think I would run some in-the-water tests and tune by ear. I'm not sure if the motor is actually running and the cam is activating the valves as it should, that you really have anything to gain by pulling the front timing cover, but I can assure you it would be A WHOLE LOT EASIER TO DO WITH THE MOTOR OUT OF THE BOAT. I made the mistake of installing before I checked for oil leaks and had to wrestle with a nasty little issue for weeks thereafter.

I posted your dilemma on another source of information and we'll see if anyone can give us some pointers. Stay tuned.

best,
Paul
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