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BamaJet

  • Karma: +0/-0
All I can find around here at the marinas is 87 octane 10% alki.

I have a 88 Chevy small block 350 with a Mallory Marine dual point distributor.

Where should I set the timing for this crap gas ?

Don
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GT Jets

  • Karma: +192/-0
Re: Suggested timing for a 350 chevy JF pump running 4200-4400
« Reply #1 on: July 04, 2014, 09:03:44 PM »
All I can find around here at the marinas is 87 octane 10% alki.

I have a 88 Chevy small block 350 with a Mallory Marine dual point distributor.

Where should I set the timing for this crap gas ?

Don

Have any more information about your engine?

4400 is quite respectable for a small black. What are you trying to achieve? What cam, exhaust, carburetor?

Most small block Chevy's get happy with between 34 ans 36 BTDC all in. That don't mean you can run that with 87 octane. Do you hear a ping?

GT
  • Boat #1: 1992 Carrera 20.5 Elite (I/O bitches)
  • Boat #2: 19' Bubble deck Jet BBC Berkeley
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If i get some free time tonight at work, ill play with it and post it for everyone to see.

Time to man up and yank it John!  :banghead:
Ray

BamaJet

  • Karma: +0/-0
Re: Suggested timing for a 350 chevy JF pump running 4200-4400
« Reply #2 on: July 05, 2014, 04:37:21 AM »
Holly 650
Performer dual plane
2.02 heads  9.0 ratio
262  hydraulic cam
through the transom wet logs
Guessing somewhere above 260 hp
"A"impeller JF pump 18 foot ski boat.

Thanks

 
« Last Edit: July 05, 2014, 10:37:06 AM by BamaJet »
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GT Jets

  • Karma: +192/-0
Re: Suggested timing for a 350 chevy JF pump running 4200-4400
« Reply #3 on: July 05, 2014, 11:05:06 AM »
Holly 650
Performer dual plane
2.02 heads  9.0 ratio
262  hydraulic cam
through the transom wet logs
Guessing somewhere above 260 hp
"A"impeller JF pump 18 foot ski boat.

Thanks

If it's not pinging, leave it alone.

The only thing I would do to that set up is cut the impeller to an AB or even a B, let her turn about 4,600 RPM+/- 100 and enjoy it. May not pick up much in the way of top speed (probably worth a few MPH), but it will be easier on the engine and let it breathe better.

Lugging it down so hard is doing more harm than the low octane fuel.

JMHO.

GT
  • Boat #1: 1992 Carrera 20.5 Elite (I/O bitches)
  • Boat #2: 19' Bubble deck Jet BBC Berkeley
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If i get some free time tonight at work, ill play with it and post it for everyone to see.

Time to man up and yank it John!  :banghead:
Ray

BamaJet

  • Karma: +0/-0
Re: Suggested timing for a 350 chevy JF pump running 4200-4400
« Reply #4 on: July 05, 2014, 03:46:44 PM »
I bought this boat in 1988 when my son and his high school buddies wanted to ski the river. There had been some serious prop accidents and I liked the safety of the enclosed impeller.

He married in 98 and I pickled the engine and put it in the back of the garage.   The grandsons ... 10 and 8 spotted the boat last year and I told them I would get it going this year.

I pulled the distributer to prevent damage when I took the engine out of the boat to freshen up the jet pump.

All was remarkably clean ... I lubed it monthly when it was being used. It had 197 hours on the meter and all has been fresh water.

Still.... after 25 years, I wanted to look at the pump.

   I did find bad u-joints .... not from lack of lube, but rather from lack of a full compliment of needle bearings in three cups ...  they were each missing one needle from the factory .. this caused the needles to not sit straight and that caused the crosses to develop slanted marks on the hardened surfaces.
I suspect the saving grace was that the driveshaft was near 0 degree to the engine and pump ... rear mount bell housing attaches to pump snout.


The pump thrust bearing was in excellent shape as well as the bushings in the bowl that support the shaft's rear past the impeller.

I added new rubber seals and packing rings.

So, for sure, pulling the engine was a good thing because of the u-joints and seals.

I replaced the distributor and timed it with a 12 volt light replacing the coil  ... the dual points open just as the mark is at 32 degrees BTDC.

I will time it under load once I get it back in the water.

I just needed a starting point to get it warmed up before I left the dock.

Many Thanks !!

Don in Huntsville 
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