OMC Cross Charge Mod questions

[930turbo]

It makes lots of additional power in the mid range, very impressive. Top end is unchanged. I have a deceleration seizing problem that is quite puzzling. It's done it three times now. I'm sure there is damage so I'll be switching back to the stock block while I repair the damage and start over.

[gdp]

Push your choke button in during decleration.

[930turbo]

I've heard the choke button approach many times and I'm sure it's a very good idea. However, I have a couple of suspicions that may be contributing to the failure. I will switch to an electric fuel pump as I feel the lack on block positive pressure may be limiting the pumps ability to deliver under light load deceleration. Also, my water pressure pegs the gauge since I added the LWP to the lower unit. I'm wondering if it could possibly be over cooling the block and causing the cylinders to clamp down on the hot pistons. I'll work on a relief to keep the LWP from boosting my water pressure. I say it's puzzling because I did this same thing with a Force 85 that had no failures in four years. It had an electric pump from day one and pickups that did not force feed. This could be one of those mountainous mole hills but I've got to try something. I want to reduce wrenching and increase drive time.

[john j 80 viking]

A better option for the water pressure would be to block off some of the water inlets on the nose cone (like the two outer ones) for less drag. It usually makes a noticeable difference in top speed.

[evilrude 1]

It makes lots of additional power in the mid range, very impressive. Top end is unchanged. I have a deceleration seizing problem that is quite puzzling. It's done it three times now. I'm sure there is damage so I'll be switching back to the stock block while I repair the damage and start over.

If your jetting is on the edge it will go lean when you lift your foot. Jet up or use the choke-just my 2 cents.

[930turbo]

The jetting is Stock but that could be lean.

[evilrude 1]

The jetting is Stock but that could be lean.

I would really go up on the mains and intermediates. Especially if the engine has been "worked" in any way.
Crossflows are very unforgiving. Even stock jetting and timing are a little too extreme for today's lead free alcohol fuel.

[FMP]

Spybot

[spybot]

I am reading and taking it all in
Andy

[FMP]

Some good info, found another with some good pics of a V4 chest modded nicely.
Leave duration about the same and it sounds like it runs right out of breath. Plenty V4 xflows run more rpm, as I'm sure you've read.

[spybot]

found another with some good pics of a V4 chest modded nicely.

??????

[FMP]

I did, just don't know where lol
Maybe I can find it again. What happened to that link.

[racervboat]

Well I just read this whole thread.In my experience 135 & 140 heads are the same with a snap-on and a sears comp gauge I gets 135-140 how you getting 155 I don't know are you shaving the heads? even with my 140 shaved heads its 135-140 psi ? You need to run an elec fuel pump. Also my motors are all dry stacked no stats no popetts dump the head hoses right out the pan. Timing at 26 @ 7000 have seen 85 mph with 26 cleaver on 15 ft pacecraft and 16ft Allison in rouny round race set-up carbs 1-3/8 or 1-5/16th with 67 or 68 mains of the 10 mod motors [ 9 pages] never had one blow up or score a piston and racing back to back 10 mi heats its wot except in the turns. jm2cents?

[racervboat]

Oh and that's running 91-92 non oxy pump gas.

[racer]

The 73 135 heads had a larger deflector on the exhaust side than any of the 140 heads. I have seen 150 plus on many early 135s using snap on gauge cranking at 250rpm