Thunderbolt V 1999 5.0L high rpm ping

[John_S]

Re: Thunderbolt V 1999 5.0L high rpm ping

What 2ndary rods are you currently running? As you probably know, you can't change the 2ndary jet. Older, non-vortec Q-jets ran with CLs for 5.0 and 5.7L. 350 Mags had the richer CH rods.

If you remove your advance module, you might find the timing curve stamped on it. It will be something like V8-22A, V8-22, V8-24, etc. The 22/24 indicates the total advance added to the base at wot. My T5 (no knock module) has a V8-22A, which can be compared to a T4 V8-22A curve for the base mode.

 

[jy118lfd]

Re: Thunderbolt V 1999 5.0L high rpm ping

The carb has CE rods in it. They are considerably richer than the CH or CL rods. The problem is that I used a later model q-jet that has the electric choke. The carb has larger air bleeds in it than the ones that were stock on marine motors. (Please everybody don't get all up in arms the carb main body was made to be coast guard compliant by someone who does these all the time.) So with the larger air bleeds comes less fuel for a given rod size. Hence the CE rods that are .041 and have long power tips.


I spoke with the guy I get the carb parts from. He is going to machine a set of DW rods I have to .035 and I will see how that does. 5 minutes and a test run to see if it still pings. I will check total timing at that time. Its frickin snowing here right now so I can't get out today.

My module just says 5.0L alpha Gen+ on it

If my timing is too far advanced total I will try to find a TB4 module with a set curve and try it.

Enough to check right now so I post back with results when I can get to run the boat. Maybe thursday


Thanks to everyones posts they really do help and keep them coming.

 

[John_S]

Re: Thunderbolt V 1999 5.0L high rpm ping

Is your ICM flat like with one row of pins, or rectangular with two sets of rectangular connectors? If the prior, it will convert easily to T4. If the latter, like what I have seen on vortec 5.7L carbed, would require a wiring harness change.

 

[jy118lfd]

Re: Thunderbolt V 1999 5.0L high rpm ping

Is your ICM flat like with one row of pins, or rectangular with two sets of rectangular connectors? If the prior, it will convert easily to T4. If the latter, like what I have seen on vortec 5.7L carbed, would require a wiring harness change.

It has two weatherpack connectors

 

[jy118lfd]

Re: Thunderbolt V 1999 5.0L high rpm ping

But I have a question, aren't the metering rods totally out of the rear main jets at WOT? If so, then you need bigger jets, instead of thinner rods, no? I would say yes, you need more fuel with that 305, simply because of the load you're carrying with that heavy boat, that maybe the answer to your problem?

By the way, NICE Boat!

Thanks for the compliment.

On a quadrajet in the secondary side the rods only raise up a specified amount even at WOR This is set by the secondary hanger height. They never come totally out of the jet. The jets are pressed into the main body and are not removable. The only modification that can be done is to go to a smaller rod. There are many rods available but the tip size is whats important. They made many tapers over the years to meet emission rules and for different engine configuriations.

 

[John_S]

Re: Thunderbolt V 1999 5.0L high rpm ping

It has two weatherpack connectors

That sounds like the latter, and you will probably not find a T4 module that plugs in.

Before going that route, map your T5 when locked in base mode. It might make it equivelent to T4. I have only mapped mine from idle to 2.5k, but it looks like that what it will do.

 

[chiefalen]

Re: Thunderbolt V 1999 5.0L high rpm ping

Really nice boat.

Just curious, you posted you just got this motor, why you didn't go with a larger motor.

Seems you have my problem to mush boat, too little hp.

That 305 ain't got the mojo to push that whale.

Why you change out the motor to begin with?

26 gph with these prices on fuel.

An i was complaining about burning 12-15 total for 5-6 hours on the water.

I'm only running the motor for 2-3 hours and not at wot.

 

[jy118lfd]

Re: Thunderbolt V 1999 5.0L high rpm ping

Really nice boat.

Just curious, you posted you just got this motor, why you didn't go with a larger motor.

Seems you have my problem to mush boat, too little hp.

That 305 ain't got the mojo to push that whale.

Why you change out the motor to begin with?

26 gph with these prices on fuel.

An i was complaining about burning 12-15 total for 5-6 hours on the water.

I'm only running the motor for 2-3 hours and not at wot.

I will try to answer your questions in Order.

The motor was in the boat from new. I would never have put in a 5.0l although it does run good. A 6.2mpi and a bravo 3 would have been my choice. (The Cummins Mercruiser diesel 4 cyl and the bravo 3 is just too much coin)

The 305 pushes the boat quite well as I get 35 knots about 40mph wot.
It cruises anywhere from 22 to 26 knots (25 to 30 mph) depending on sea conditions. It only really needs more torque when I am cruising in a following sea.


The motor was never changed

26 gph is what I think it should run at wot.Right now it is at 21 gph at WOT and I rarely ever run it there.

On a normal trip offshore we run a total of 120 to 140 miles that includes trolling for 6 to 8 hours and out and back. I usually burn 50 to 70 gallons depending on the sea state.

 

[MikDee]

Re: Thunderbolt V 1999 5.0L high rpm ping

Thanks for the compliment.

On a quadrajet in the secondary side the rods only raise up a specified amount even at WOR This is set by the secondary hanger height. They never come totally out of the jet. The jets are pressed into the main body and are not removable. The only modification that can be done is to go to a smaller rod. There are many rods available but the tip size is whats important. They made many tapers over the years to meet emission rules and for different engine configuriations.

Hey, I have internet back again! after the snowstorm it was out until this morning. Along with the power that was out about 5hrs from 1-6pm yesterday. We musta got 6-8" of windy drifting snow!

Anyway, thanks for the refresher, that's what happens when you get old, & don't do this everyday. I forgot the Qjet has fixed orifice jets in the secondary's. I must have been thinking they were like the primary jets, then you reminded me they were like little tubes, and not even brass looking. I wasn't sure if the rods came totally out of the jet either? Also, you, & Imported John are beyond me on carb tuning, and advance module info, I do understand the concept though, and can follow along, I find it informative, & interesting, info

 

[chiefalen]

Re: Thunderbolt V 1999 5.0L high rpm ping

Hope you guys that got snow didn't get caught off guard with water in your engines and manifolds.

I've been posting to drain them.

My neighbors were looking at me funny when i had my old pos tank snowblower running in the garage yesterday. I like to be ready.

jy 118 is the guy i'm going to with a carb problem i can't fix.

Back to the basics, freekin spark plug broke maybe, tip melted, bad plug right out of the box? Won't know till you pull them, and eyeball them.

To hot a plug for all that rich gas your putting in there maybe?

Could be?

Than every time you adjust the carb the timing got to be adjusted?

 

[jy118lfd]

Re: Thunderbolt V 1999 5.0L high rpm ping

I picked up a set of MR43LTS plugs and will try them on thursday or friday. It did not cost much and will eliminate the plugs as the cause. I like the iridium plugs cause it seems to start easier and after 250 hours they show no wear. But If I have to run the delco plugs so be it. I will also check the total timing and map the timing curve the best I can.

 

[jy118lfd]

Re: Thunderbolt V 1999 5.0L high rpm ping

I found this in the #24 manual. It might help some. Sounds like it does not need the knock sensor to set the timing.


ACCELERATION SPARK ADVANCE
When accelerating, the Ignition Module may add more spark advance to the ?Base Spark
Timing Curve.? The amount of spark advance added depends on how fast rpm increases.
This feature is also active between 1200-4000 rpm. Within this range, the module can add
approximately 10 degrees of spark advance to the base spark timing curve.
MEAN-BEST-TIMING (MBT) SPARK ADVANCE
During light load cruising, the Ignition Module maintains optimal ignition timing by making
small spark advance adjustments. At a given rpm, the module will add a small amount of
advance and wait to see if there is an rpm change. If rpm increases, it will increase timing
more. The module will continue to advance timing until it no longer gets an increase in rpm.
Conversely, if it senses an rpm drop, it will start to retard some of the spark timing. Between
1200-4000 rpm the Ignition Module can add approximately 10-15 degrees of spark advance
to the base spark timing curve.
NOTE: The Audio Warning System is also connected into the Ignition Module circuit. If the
audio warning system becomes activated by the closing of one of the audio warning system
switches, the MBT feature is deactivated

 

[John_S]

Re: Thunderbolt V 1999 5.0L high rpm ping

I thought you were getting the ping at only high-rpm. According to the "generic" T5 timing chart, from 4K to 5K, the max ignition timing should be equal to base timing. ie it can only retard if a knock module was present. Accel Adv Range and MBT should not be adding advance at wot. Keep posting on testing results.

BTW, do you have any plug readings from wot?

 

[jy118lfd]

Re: Thunderbolt V 1999 5.0L high rpm ping

I thought you were getting the ping at only high-rpm. According to the "generic" T5 timing chart, from 4K to 5K, the max ignition timing should be equal to base timing. ie it can only retard if a knock module was present. Accel Adv Range and MBT should not be adding advance at wot. Keep posting on testing results.

BTW, do you have any plug readings from wot?

Correct only at 47 to 4800 rpm. I just posted that to show how the TB5 sets timing. I really can't wait to see wht my total timing is

 

[MikDee]

Re: Thunderbolt V 1999 5.0L high rpm ping

Correct only at 47 to 4800 rpm. I just posted that to show how the TB5 sets timing. I really can't wait to see wht my total timing is

You would think if you set the initial timing correct, and the timing reaches it's maximum amount of programmed advance, usually before WOT, then there are possibly other issues causing the pinging? it could be a lean condition as you were thinking, Or (a wild eyed guess here), maybe the weight with the timing mark on it slipped on the balancer? and the mark is not on true TDC anymore?

 

[jy118lfd]

Re: Thunderbolt V 1999 5.0L high rpm ping

You would think if you set the initial timing correct, and the timing reaches it's maximum amount of programmed advance, usually before WOT, then there are possibly other issues causing the pinging? it could be a lean condition as you were thinking, Or (a wild eyed guess here), maybe the weight with the timing mark on it slipped on the balancer? and the mark is not on true TDC anymore?

That is a possibilty. I have seen balancers slip and change the timing marks. I can check that also when I have the plugs out. Good observation.

I am leaning (no pun intended) towards a lean condition or an incorrect heat range on the plug. We will find out this weekend. Hopefully

 

[MikDee]

Re: Thunderbolt V 1999 5.0L high rpm ping

Thanks to Haut Medoc for his input, and the service manual link I just copied this out of it to post here:

Spark Plugs
Model All MIE and MCM Engines
Spark Plug .045 in. (1.1 mm)
Spark Plug Type
AC-MR43LTS
NGK BPR6EFS
Champion RS12YC

I see they are long reach plugs by the letters, If your NGK's are not this number, you have the wrong plug. A note here, a hotter plug by NGK is actually a lower number (like a BPR5EFS), contrary to most manufacturers where a hotter plug is usually a higher number.

I used to fool around with tighter plug gaps, having heard that it increases performance, but I have personally found, and read this somewhere yrs later, that it advances your timing a bit (that's why in 1975 when they first came out with GM HEI ignition, I tried setting my plug gap to .035, instead of the recommended .045, and got some pinging). I have since been careful about that.

Personally I put Champions in everything, the engines always seems to put out more power with them. Maybe it's the fact that they're usually a projected nose plug (supposedly for better cooling, & cleaning), But, personally I think maybe it just raises the compression a little bit, Whatever? It's always worked for me, plus I like a plated plug in my vehicles, anything else can rust into the head, I've had that happen on a Ford 302/188 hp Merc. (I had to take the head off, to get it out! rusted, black steel AC's) Not fun!

 

[chiefalen]

Re: Thunderbolt V 1999 5.0L high rpm ping

I like champions also.

Got to go back to the basics, old school.

Everything else don't work.

I did see the timing mark also move on some motors.

See what happens when you get to be a old fart like me, you get crs, i should have mentioned it.

Mikdee is good real good.

 

[MikDee]

Re: Thunderbolt V 1999 5.0L high rpm ping

Hey Chief, We're all here to try, & help, that's a Good thing,,,, we all have something to contribute,useful at the time, or not, and it's like a big jigsaw puzzle, some good brain exercise for us old farts, it helps jogging the memory, and gettin the cobwebs out, plus we learn a little more each time, never a bad thing!

 

[jy118lfd]

Re: Thunderbolt V 1999 5.0L high rpm ping

The MR43lts I've seen are either plated or stainless. The black plugs are r43lts. I like champions in anything with cast iron heads as well but as a mechanic for 12 years I have removed countless aluminum heads cause the champions welded themselves to the threads.

But I will not run anything other than a champion in a johnson/evinrude 2 stroke. I have seen to many broken pistons in them with NGK plugs.



I have TR6IX Plugs which are the Iridium Plugs. They cross to a BPR6EFS