Timing Specs for H/M 351W

[JimG]

Hey guys, any idea what the timing specs are for my motor? And... how do you get the &^%*&^# spark plugs out around those nifty Edelbrock manifolds? :o
Am I going to have to remove the manifolds to replace the plugs?

Thanks!!

JimG

[Forrest]

Jim, it's probably a good time to pull those old Edlebrock logs and take a good look at them anyway. If one those puppies springs an internal leak, you won't be worrying about to be changin' plugs or settin' timing. eek! Anyway, on that F-word motor, or even a marine Chevrolet motor for that matter, you probably want somewhere around 32 to 34 degrees total with an initial timing of about 10 degrees BTDC. You can fin your optimal total timing by making a run at say 32 degrees noting top speed and RPM. Then after the run, bump the timing to 34 degrees and make another run. Do the boat go faster? If not, set it back to 32 and you're done. If you went faster at 34, then try 36. Go for as much timing as you can until you see no increase in speed. Remember, you want no more timing that you absolutely need for best top end. Also, if you happen to hear any detonation (knocking or pinging) at any speed, you will need to back off of the timing, or have your distributor advance re-curved for less timing in the RPM range where detonation occurs. Detonation will ruin your boating season.

[mattyboy]

Jim,
I have a special tool given to me by the gentleman who built my boat and it works great,
it is basically a box end wrench cut in half, I'm workin my way into the garage I'll post a pic as soon as I can, I'm assuming you have the old H\M log manifolds

Matt

[DON N.]

I HAVE A SHORT 13/16 & 7/8 12 POINT BOX COMBO,I CAN CHANGE THE PLUGS WITH H & M MANIFOLDS + UNSCREW OIL PLUG WITH OTHER END. LOOKS LIKE THE ENDS ARE @ ABOUT 15 DEGREE ANGLE.

[penbroke]

I had the same problem getting at the spark plugs on my small block Ford with the big square Barr Marine manifolds. I could get 6 of them with an offset box end wrench but not the other two.

This is the solution I came up with:

http://www.donzi.net/photos/penbroke_plug_socket_1.jpg

http://www.donzi.net/photos/penbroke_plug_socket_2.jpg

It is made from a 13/16" 12 point socket cut to about 1-1/8" long welded to a 3/8" extension cut off to about 1-7/8". Be sure to orient the square recess on the extension as shown so a 3/8" breaker bar will extend straight off the side of the socket.

Hope this helps. It works great for me!

Frank

[Moody Blu']

the glenwood headers arent much better :o
I've broken a plug or 2.


I like that socket set up frank, nice welding job wink

As For the timing forrest is right advance the ignition until you lose speed/power.You can definately gain some speed/power if you play with the timing, it just depends on the motor. As long as you keep the timing in the safe zone. No one needs a melted piston. wink

<small>[ March 31, 2003, 10:23 PM: Message edited by: Moody Blu' ]</small>

[BigGrizzly]

I use a shortie offset box from Snap-on. On manafold you have 3 choices 1) center risers from Pleasure craft marine (read that Master craft or Ski nautique) 2)Osco has center risers which are still better than what you have by a long shot 3) Custom Marine industries(CMI) tube type for $2500!

[MOP]

I am pretty sure the largest outlets are on the Osco center rise that is the ones I went with after measuring a couple. You can find a complete setup for close to $400. If you can find a deal on better types you may want to go that way.

[Team Jefe]

That is a nice weld Frank.

Jim - Is this where we talk about the Metallurgical microstructure of Aluminum, and how it reacts ina Saline environment with other metals to set up a Galvanic corrosion cell... Or was that somewhere else?

JEFE

[JimG]

Jefe, no it's not! He he!! :)

I'm not replacing the manifolds, guys. Just the spark plugs! :D

Thanks for all the help! Love the custom tools! Where's my bench grinder?

JimG

[turbo2256]

I will agree with Forest on total timing figures but with my Ford small blocks 20 degrees inital is what usally works out for me. 6 to 8 at the distributor giving a total of 32 to 36 at the crank. The distributor curve depends a lot on the port efficency.

[penbroke]

I wish I could take the credit but one of the guys at work did the welding. It's still too cold to do much work in my garage/shop.

I have passed on the compliments.

Frank

[Stuart]

Hey Jim, your woes will continue until you...

pull the motor.

P.S. Listen to Forrest and Griz.