boot

124's ,wow ! Well , We went out ,put in V6 modules .they work great .
installed fuel pressure gauges . 8 1/2 -9 psi at idel anyother rpm about 7 1/2 psi .
98 jets , they could use more maybe .Will try 100's next time . Had all new NGK plugs in except one . One of them broke so he put an AC plug in place . After a long run ,ideled for a while ,engine stalled . Started fine ,went back to adjust carbs stalled again . When restarted all hell broke loose ! BOOM ,BANG , CRASH !!
Pulled plugs out .THe one AC plug was not even finger tight and the end was burned off ! (This has happened before with the ac's ). That cylinder also broke a valve seat and sent peices flying ! THis is about the 5th time he has had problems with AC plugs loosening up and / or blowing the centers out and/or melting the tips ! And the second time it has caused engine failure .......
Not sure of total damage yet . I'll let you know .

PS , tried to get Bruce for a while now .Can't do it .....

Also these carbs came from Nickerson originaly . He said they should have 96's . NO WAY for this boat .

OH well , Just another day in paradise !

Turbojack

For plug to let loose motor was detonating. Was the cylinder #7?

boot

Can't remember which one but when facing the front of the motor ,it was the second or third one back on the right side .

This motor did it several times when stock too . Only with the AC plugs .

Gumbydammit

Joe, that SUCKS!!!!!!!!!!!!

Ouchie.

or is it ouchie$??

Good luck and may your machine shop bill and time be light.

KAAMA

Bruce Wolff is in and out of his shop a lot. If you'll keep trying you might catch him.

John B

What heat range plugs are you using? Were you blowing the plug tips out of a stock motor!!!??? Did you check the fuel pressure at (WOT) wide open throttle. What total timing do you run? Did you run it wide open or just cruising before it blew?

There is a lot of experience here, but we can't help much without all the facts.

One hot (heat range) plug could cause all this damage by itself. All plugs can back out when detonating or preigniting. That caused the seat to fall out and /or break, then parts fly all over, discouraging.

I have been thru all of this s--t. Turbo probably too.

Most of the successful blower motors run detonation sensors, and fuel presure gages, because blower motors are critical. If there not right on (all) the time they blow!

Keep the faith, JB

John B

With a V-8 module the ignition timing doesn't start to advance until maybe 900 rpm's. If I remember-- it also has about 20 degrees of advance in it. On a blower application you need about 30 degrees total so set the initial at 10 degrees.

The V-6 module has about 14 degrees built in, so the initial is set at 16 to give 30 total. 16 initial will give you a better idle quality and is less pron to backfire when cold. BUT The distributer starts to advance at 500 to 700 rpm, so the timing is changing when you go in and out of gear. Idle speed gets difficult to control. Just check a V-6 module with a timing light. You can us either, this may help you determine which one to use.....

JB

boot

John B, the fuel pres. was never below 7 1/2psi. The plugs were stock AC's now they are NGK's .The only one that acted up was the AC . V-6 module max is 30 degrees .

We ran about 5 miles easy ( around 3500-4000 rpm's ) then made a few hard runs (wot) for about a minute or 2 . Then ran back about 5 miles or so at aroung 3800 rpm's . Motors ran fine .Had the hatches part open and I had my head in there checking and listening ! NO ping or knocks at that point ,even wide open . WHne we got back , the port motor was ideling low (500 compared to 900) I jumped back there to adjust carb, It stalled in gear , started fine ,in a minute or 2 stalled again . WHen restarted , BANG POW CRUNCH !!

Brakeing news I found out today : Owner, friend of mine admits the head bolt holes didn't get re tapped . He said they got tight before they should have when tightening them . ALL the cylinders had water in them from the head gaskets leaking on every cylinder !

Just some advise to others , Don't over look something thinking it will work out because you don't want to waste time taking it apart to fix it . Do it right the first time ! We all cut corners sometimes .But it usualy bites us in the ass !

John B

The old stretched head bolts (bottomed out) deal. Another bit of experiance. ARP bolts, read the instructions carefully. So many problems for so short summers.

Spark plugs have different heat ranges, cold ones for hot engines. It's all in the books---also may be on the web.

Turbojack

I have lost count since 1973 of the turbo and/or blower motors I have distroyed due to detonation. I have never ever heard any of them detonating. Due to exhaust & wind noise I can not hear the motor coming apart until it is to late.