78 S&S timing

[ctjahn]

Long story short before I rotated the Pertron, I wanted to check the distrib.

It appears one of the springs is missing... Is there a source for a spring on a distributor????? I suspect it is has specific tension and etc so I cant buy one just off the shelf at the hardware store?

Still not sure if this would cause the issue. And it would be a heck of a coincience that it broke and/or disappeared around the same time as the pertron was installed.

cj

[1redTA]

I am interested as well, of the two springs,on mine, one is very small and attached to the pins with tension on the spring however, the big one is resting over the pins with no tension just voer the pins. Worst of all I get 24* at 4000rpm anyone no what the timing should be at that speed?

[ctjahn]

I contacted skidim and others for advise on where to source it out... My next step is buy one from a 1978 ford from a junkyard. (whole distrib)... Will let you know what I find out.

cj

[liledgy]

Did you swap out your coil yet?

[ctjahn]

Originally Posted by 1redTA

I am interested as well, of the two springs,on mine, one is very small and attached to the pins with tension on the spring however, the big one is resting over the pins with no tension just voer the pins. Worst of all I get 24* at 4000rpm anyone no what the timing should be at that speed?

Skidim got back to me. One is supposed to be big the other one is supposed to be small. They used to sell replacement kits years ago but dont offer it any more. No one else was able to provide a set. I did pickup a set of springs for a GM distrib and may give em a try if nothing else turns up.

cj

[ctjahn]

Originally Posted by liledgy

Did you swap out your coil yet?

Not yet. The springs I am talking about affect the timing as the speed/RPM increases. So one would assume this isnt helping things. I dont live on the lake so testing is an ordeal. I am going to try the spring first, retime again, then the coil (I guess I could put the old one back in), and finally put the pertron to CW instead of CCW like they said (but I doubt this will even work?)

[ctjahn]

Got a spring kit from MR Gasket. Installed one silver spring (max stiff) and one black spring (min stiff). Will time it again next weekend on the fake lake (Its sleeping in the garage and as I suspect that the timing is off because the old remaining spring was doing nothing. And I suspect it advaced itself to max when at idle.)

cj

[ctjahn]

Great day on the lake! Last weekend Tuned up with new cap, rotor, plugs, (Gapped to .040 with Pertron)...and plug wires. Long story short....Issue resolved (not that it was that big of a deal because we didnt use 30-40mph for skiing but... it still bothered me that it wasnt right)

The springs in distributor were completely shot. One was gone, the other one rusted and crusty. Not really doing much. So when I adjusted the timing the distributor was at full advanced (nothing was holding it back). I talked to a boat mechanic and he verified that he thought that the springs were the source of issue)

On a guess (Since no one makes a spring kit any more); I got this from Tims (the local auto parts store) and gave it a a go: Mr. Gasket 929G - Mr. Gasket Advance Curve Kits (RACEONLY for GM Motors). I guessed again and used the lightest spring (Black) and the medium spring (Silver) - based upon TT feedback. Tested on the fake lake in the driveway and the timing advanced to 28/29 degrees at 4000 rpm. (Boat mechanic said it would be nice to see about 24-30 @ 4000. (Might switch to the heaviest gold spring instead of silver)

Ok, so it advances now... the real test was to do it under load. Took it out @10am. It ran perfect though the rev band. Power across the board. Boat runs and sounds better than ever! 39mph @ 4000 RPM. (I think thats on a 13x13 prop). Great out of the hole. Great top end. Kick a$$

Went to launch out and I had my own little 1.5 hour wait of boat lauch bloopers... (Ugh) but a great day on the lake and great weather while watching the drama made it ok. (although I think we cooked while waiting)

For those who can use this in the future, please note the Mr Gasket 929G part number... (only $5 -10.00; a heck of a lot cheaper than a distributor) Hope this can help out other folks as the TT group has been a great help to me.

Cj

[TRBenj]

Originally Posted by ctjahn

the timing advanced to 28/29 degrees at 4000 rpm. (Boat mechanic said it would be nice to see about 24-30 @ 4000. (Might switch to the heaviest gold spring instead of silver)

39mph @ 4000 RPM. (I think thats on a 13x13 prop).

28-29 degrees at 4000 is way too low, and way too late. You should see full advance by 3000 rpm, and ideally you'd be getting 35-36 degrees of total. If you recurve the distributor to achieve that, you will notice a huge improvement in low-midrange acceleration, and will likely find the 400rpm and 4mph that youre missing.

[ctjahn]

Originally Posted by TRBenj

28-29 degrees at 4000 is way too low, and way too late. You should see full advance by 3000 rpm, and ideally you'd be getting 35-36 degrees of total. If you recurve the distributor to achieve that, you will notice a huge improvement in low-midrange acceleration, and will likely find the 400rpm and 4mph that youre missing.

Sorry for the confusion... It maxed out at 28-30 degrees... Where it hit was tough to say (holding the timing light foot on the throttle, while trying to monitor, and not piss of the neighbors at 8am on a saturday); I just know it maxed at 28-30 or so at 4k.

Hmmm, since I am running the lightest spring and the medium heaviest spring; I could try to remove the light spring and just run on one? It does kick out of the hole quite well tho. (and after getting it running well, I would hate to break it now that it works!)

EDIT: In the garage this morning for work I did notice that the prop was 13x14LH....

cj