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johny_Utah
06-14-2006, 11:56 PM
We are getting there. I have been working on my boat for 2 weeks straight.

To Business; my numbers on the flywheel to tell me degrees are worn off. I do have a mark "TDC". Is this the top dead mark? If so is there an actual measurment from this mark for 6 or 10 degrees so I could use a measuring tape?
Does anyone bypass the fuel seperator?
where do you get new springs inside the distributor that holds the weights back?
When do you know if you need to replace the distributor?

And the whopper. All my plugs look black (which I know is rich, working on it) except the front right looking at the motor from the observers seat. It almost doesn't look used. Any ideas.

Thanks a ton for all the help so far.

J

Hunterb
06-15-2006, 02:31 PM
Yes the TDC mark should be the point where the #1 cylinder is at top dead center of it's compression stroke. It seems strange that the numbers are 'worn off' but it doesn't really matter that much. For unknown, but probably related to the mechanical skill of the previous owner, the numbers on my balancer are miles off what they should be. I made a new TDC mark and use that as a reference when I time the motor. Simply loosen the distributer bolt and turn it back and forth until you find the spot that produces the highest idle, or the most vacuum if you have a guage you can hook up. Using a timing light you can see the distance from the TDC mark to the point where you have it set. Stop the engine and make a mark on your balancer at that point. You can then advance or retard your timing slightly to get the most out of your motor using that as a 'benchmark'. It's not terribly important what the actual number is.

I do not bypass the fuel/water seperator.

You should be able to purchase the distributer weights at any auto supply store.

You need to replace your distributor if there is significant play in the shaft and, if you are still using points, I would recommend the electronic conversion.

As for the unused looking plug; is it firing? Hook your timing light up to that wire and see if it's working. If it looks unused and it's wet then it's probably not firing. Change plug, change wire, change dist. cap. Have you done a compression test. Worst case scenario is that you have a dead cylinder.

Not sure if any of that helps. Good luck with the project and post back on progress. There are some people on this board that know lots more about motors than I do and they will probably jump in to help now that I've muddied the waters for you.

Bruce

butter
06-15-2006, 07:11 PM
Do you know, or can you measure, the diameter of the pulley? If so, you can calculate a measurement for "X" degrees using...

Y = ( 3.14159 * D * X ) / 360

Where:
Y is distance (along the outside diameter of the pulley) from the TDC mark.
D is the pulley diameter.
X is the angle from TDC you would like to mark.

There may be some error depending on the accuracy of your measurements, but you should be able to get close.

Good luck!

johny_Utah
06-15-2006, 10:17 PM
Thanks guys.

Butter- Very impressive.
HunterB- Which way do I get a better hole shot? Advance or Retarded?

J.

6ballsisall
06-15-2006, 10:28 PM
Thanks guys.

Butter- Very impressive.
HunterB- Which way do I get a better hole shot? Advance or Retarded?

J.

IIRC, Retard it. You'll get less R's though.

Hunterb
06-16-2006, 01:22 PM
I'm not sure which way will give you a better hole shot. To be honest, what I did with mine was fiddle with it until it ran the way I wanted and then made a mark at that point that I now use as a reference when doing any timing. I think your carb adjustments will have more to do with a better hole shot than your timing. Timing is really a compromise between what works best at idle and what works best at WOT and the weights in the distributer 'manage' the movement between the two. You can get carried away and buy different weights that will change the timing curve, but I've never done it. Trial and error will give you the best setting and it's quite easy to do really.

Good luck with the boat. Hopefully you get it up and running soon.

Bruce

WTRSK1R
06-16-2006, 01:39 PM
Keep in mind if you get the timing too far off, the motor will be hard starting, and could backfire at WOT. I had an issue with timing that would periodically cause the motor to be hard starting, and then at times it would end up getting flooded. I adjusted it back to the original Spec, and never had another issue.

Hunterb
06-16-2006, 02:19 PM
That is true. I think if you are too far advanced it can make it tough to turn the motor over when it's hot.

Thinking of the calculation recommended by Butter you could also estimate this by simply drawing lines on the pulley. If you started with two lines at 90 degrees to each other which cross in the middle of the pulley and one of them passes through the TDC mark then you have an accurate measurement to 90 degrees from TDC. You could then bisect that angle to find 45, then again to get 22.5, then again to get 11.25, (which is auful close to 10) then again to get 5.75

If measure careully you should be quite accurate.

We'll get this thing timed yet !!

Bruce

tommcat
06-16-2006, 03:32 PM
Advanced timing will give you better low end.

you can just go to a performance shop and pick up timing degree tape. once yoy mark actual TDC on the timing wheel you wrap the stick on tape around the wheel and all the timing degree numbers are printed on it. make sure you check for actual TDC though, dont rely on the mark to be accurate.

butter
06-16-2006, 03:35 PM
Which way do I get a better hole shot? Advance or Retarded?
I don't think there is a simple answer to this question. Advancing the timing relative to the manufacturer's spec may enhance performance up to a point, but you risk "pinging", detonation, burning holes in your pistons, etc, etc... Retarding the timing relative to the manufacturer's spec will generally hurt the performance. In some rare cases, it is advisable to slightly retard the timing relative to the manufacturer's spec in order to avoid "pinging" with lower grade fuel.

Some people have good success setting the timing by "ear". I am not one of them. I have done it that way on occasion, but always get better result using a timing strobe, timing marks, and the manufacturer's spec. I recommend finding/measuring the correct timing mark on your pulley, in order to set the timing correctly.

OR, you could buy/borrow a timing light with an "advance" feature. It will tell you how far the timing is advanced, using only the TDC mark. Here is an example of such a light...

http://www.partsamerica.com/ProductDetail.aspx?categorycode=3390&mfrcode=EQU&mfrpartnumber=3555

There are more expensive ones available also, with more accurate, digital displays.

Good luck!

dog paw
06-16-2006, 04:33 PM
Yes the TDC mark should be the point where the #1 cylinder is at top dead center of it's compression stroke. It seems strange that the numbers are 'worn off' but it doesn't really matter that much. For unknown, but probably related to the mechanical skill of the previous owner, the numbers on my balancer are miles off what they should be. I made a new TDC mark and use that as a reference when I time the motor. Simply loosen the distributer bolt and turn it back and forth until you find the spot that produces the highest idle, or the most vacuum if you have a guage you can hook up. Using a timing light you can see the distance from the TDC mark to the point where you have it set. Stop the engine and make a mark on your balancer at that point. You can then advance or retard your timing slightly to get the most out of your motor using that as a 'benchmark'. It's not terribly important what the actual number is.



Bruce


Come on peeps you can do better than that :confused: First off it sounds like your harmonic balancer (front hub) has slipped on its rubber core. What you just desribed for TDC in reality is prolly around 20+ deg advanced. DO IT RIGHT! Those little things will bite you bad if you are not carefull. To do it right put a dial gauge in the #1 plug hole and let the gauge tell you where the top is Use a long screw driver as a worse case shadetree method. If the balancer moves again your back to square one. Dont deto a piston over something so easy to do right. Last year I lost $1500 worth of rotating parts in a high end engine all over less than .010 squish clearance. (piston to head clearance) Thats about a piece of paper folded twice Think what 20+ deg error in timing might do :eek:

I got dist advance springs from JOA Mastercraft

johny_Utah
06-16-2006, 07:22 PM
I like the screwdriver in the number one hole idea. That will make sure TDC. Then I can work from there.

Lets talk a little about spings and weights in the dist.. Lets say a guy has a broken spring in there (which I have) what does this do to the motor. Also the weight was spinning in there with no resistance without a spring. Could the weight wear down?

Really the question is what the hell do the weights do?

I ordered Electronic Ignition from Discount Inboard so I am at a stand still until Wed..

J.

WilliM1940
06-16-2006, 09:09 PM
The weights are a centrifugal advance mechanism, that is as the motor speeds up, the timing is advanced by the weight mechanics being thrown outward. These push some type of cam arangement which rotates the guts of the distributor, advancing the spark timing. In the old days this was augmented by a vacuum advance also, which through a vacuum actuator, altered the advance curve also. Don't know why that isn't used here. If one of your springs is broken my guess would be your timing is advancing quicker than it should, so your fuel/air is less compressed when firing takes place. Lack of power and efficiency would result. Maybe this is what is causing your black plugs, a bad burn.