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-   -   Backfire Issue, need advice. (https://www.offshoreonly.com/forums/do-yourself-boating-budget/336597-backfire-issue-need-advice.html)

hblair 04-25-2016 11:59 PM

Actually Joe, I'm sitting here in bed planning out in my head reinstalling the blowers. It will be after our gulf shores trip maybe week after next. Stay tuned. ��

hotrodford 04-26-2016 11:04 AM

crane did build ignitions , check total timing on back fire

sprink58 04-26-2016 12:49 PM

I've been there with MSD marine stuff. I'm sorry...I don't trust it...seems to fragile to me.

When you get back from the Gulf..give DUI in Memphis a call. They have a small cap HID that might work within your space limitations.

Be safe and have fun.

MILD THUNDER 04-26-2016 12:53 PM

I see alot of guys recommend the DUI ignitions. Never used them. They are pretty much an HEI arent they? Are they tuneable? What do they cost ?

sprink58 04-26-2016 04:06 PM


Originally Posted by MILD THUNDER (Post 4432743)
I see alot of guys recommend the DUI ignitions. Never used them. They are pretty much an HEI arent they? Are they tuneable? What do they cost ?

Check it out...
http://performancedistributors.com/

http://performancedistributors.com/p...-distributors/

http://i705.photobucket.com/albums/w...ps608ed737.jpg

http://i705.photobucket.com/albums/w...psda43084b.jpg

I had the guys at DUI set mine up for my Twin Vortec SBC Roller Cam Motors. I set the timing at 8 deg initial and I have a total of 30* at 3000.

Their marine spark plug leads are as good as I've ever seen.

getrdunn 04-26-2016 07:23 PM


Originally Posted by sprink58 (Post 4432741)
I've been there with MSD marine stuff. I'm sorry...I don't trust it...seems to fragile to me.

When you get back from the Gulf..give DUI in Memphis a call. They have a small cap HID that might work within your space limitations.

Be safe and have fun.


Only way to go in my book given the hp and rpm I run. I wouldn't consider anything else. How many threads you see regarding issues or tracking problems with HEI. Dui. Rev limiters available for a little over 100.00 and can get into the marine dui for under 300.00. Two wires and your done. Some tunnel ram guys have clearance issues but not many of those running offshore anyway.

Fully tunable with spring/weight kit. Very easy to make changes.

MILD THUNDER 04-26-2016 07:30 PM

Looks like 320 bucks for the Marine DUI setup? Their site shows that they don't sell a different advance curve kit for their distributors, and that they tune them for your engine when you purchase them. If you want a rev limiter, which I would think every hi perf marine engine should, thats another 145 bucks. So, looking around 465 dollars, for an ignition you can't tune yourself, no things like custom 3d programming, pre selectable marine timing curves by turning a dial, start retard, idle stabilization, data logging, and so on.

Thats a tough call. For around another 75-100 bucks, you can get into a Daytona ignition, that has a ton more features. I think its well worth the extra cost, to have the capability to run lots of timing at idle, pull it back off idle, ramp it in per RPM based, or go 1 step further, and use a map sensor, and have a 3d timing map.

With that being said, I do understand guys liking the simplicity, and 1 wire hookup of them.

dunnitagain 04-26-2016 08:30 PM

MSD Ignitions are VERY Ground Sensitive. Check your Dist to Coil Phasing is Correct. Your Problem sounds like you have the Purple and Green Wires from Dist , Crossed 2 the Coil. They will start and run, but the reversed coil phasing , will not generate enough spark intensity to fire the plugs . Hence the Black plugs.

getrdunn 04-26-2016 09:20 PM


Originally Posted by MILD THUNDER (Post 4432846)
Looks like 320 bucks for the Marine DUI setup? Their site shows that they don't sell a different advance curve kit for their distributors, and that they tune them for your engine when you purchase them. If you want a rev limiter, which I would think every hi perf marine engine should, thats another 145 bucks. So, looking around 465 dollars, for an ignition you can't tune yourself, no things like custom 3d programming, pre selectable marine timing curves by turning a dial, start retard, idle stabilization, data logging, and so on.

Thats a tough call. For around another 75-100 bucks, you can get into a Daytona ignition, that has a ton more features. I think its well worth the extra cost, to have the capability to run lots of timing at idle, pull it back off idle, ramp it in per RPM based, or go 1 step further, and use a map sensor, and have a 3d timing map.

With that being said, I do understand guys liking the simplicity, and 1 wire hookup of them.

take that back. Pertronix marine flame thrower is whet I currently have and they came with tune kit. No noticeable difference than dui. ck those out. Vacuum or mechanical advance. Mine run well on the dyno in direct comparison to high dollar Speed shop ignition including plug wires the size of my fingers. Dyno results were "0" difference.

getrdunn 04-26-2016 09:28 PM

I just hate chasing problems. I enjoy building engines etc however when it comes to boating when I head out the Chanel who's to say where I'll / we end up. I think nothing of crossing the pond at 7:30 in the evening and make it back for work in the morning. They've just been super reliable but I must say I've had great luck over the years with the old t-bolt merc ignition also.

hblair 04-27-2016 10:48 PM

Again thanks for all the input. We put the boat in the water this afternoon and test ran it. It ran strong. But discovered blown head gasket on Rt side of left engine. Seeings how we're gonna have the left intake off anyway, we may just go ahead and put the blowers back on now.

sprink58 04-28-2016 05:08 AM

OK then...you guys are probably getting pretty good at this by now !!! LOL

hblair 04-30-2016 09:42 PM

Where there is a will there is a way (and a grinder and a cut off saw and a welder). Never could get the MSD units to work, put the ground and the hot straight to the battery, no dice. The tech support guy said to ground the heads to each other then to the negative battery post with 10 gauge wire. I decided to modificate (my own word) the HEI's. This is the first vehicle I've ever owned with blowers and I like it. I have some nicer looking plumbing coming for the carbs. Just happy to hear them running....

https://youtu.be/_W1LQeRN2YU

sprink58 05-01-2016 04:39 AM


Originally Posted by hblair (Post 4434121)
Where there is a will there is a way (and a grinder and a cut off saw and a welder). Never could get the MSD units to work, put the ground and the hot straight to the battery, no dice. The tech support guy said to ground the heads to each other then to the negative battery post with 10 gauge wire. I decided to modificate (my own word) the HEI's. This is the first vehicle I've ever owned with blowers and I like it. I have some nicer looking plumbing coming for the carbs. Just happy to hear them running....

https://youtu.be/_W1LQeRN2YU

Damn distributors....I knew it !!! LOL Sounds sweet !!! Oh.and....BTW...I "Modificate" things all the time !! LOL. Must be a "Southern" thing !!!
Enjoy it and "Roll Tide" !!

sutphen 30 05-01-2016 09:16 AM


Originally Posted by MILD THUNDER (Post 4432846)
Looks like 320 bucks for the Marine DUI setup? Their site shows that they don't sell a different advance curve kit for their distributors, and that they tune them for your engine when you purchase them. If you want a rev limiter, which I would think every hi perf marine engine should, thats another 145 bucks. So, looking around 465 dollars, for an ignition you can't tune yourself, no things like custom 3d programming, pre selectable marine timing curves by turning a dial, start retard, idle stabilization, data logging, and so on.

Thats a tough call. For around another 75-100 bucks, you can get into a Daytona ignition, that has a ton more features. I think its well worth the extra cost, to have the capability to run lots of timing at idle, pull it back off idle, ramp it in per RPM based, or go 1 step further, and use a map sensor, and have a 3d timing map.

With that being said, I do understand guys liking the simplicity, and 1 wire hookup of them.

I've seen 3 DUI marine distributors come apart.been a couple years but 2 went out in 1 summer and the other went 2yrs later.went w/ gm hei distributors small cap 2 wire hook up.been fine.If we're to do it again,I would go w/ the Daytona set up.very nice piece.

Rookie 05-01-2016 09:38 AM

Does the MSD distributor need to be phased? or is that something different than when I had to phase my TB distributors when I went to my Crane HI-6M's? Just curious, I'm really ignorant when it comes to ignition/timing:)

SB 05-01-2016 10:58 AM


Originally Posted by Rookie (Post 4434211)
Does the MSD distributor need to be phased? or is that something different than when I had to phase my TB distributors when I went to my Crane HI-6M's? Just curious, I'm really ignorant when it comes to ignition/timing:)

Different.

You had to phase the TB's ahead because to change advance electronically takes varying amounts of retard. You can't advance something (electric) in time that already happened (mag pickup event), but you can delay it. That's why kind of hard to understand, but easy once you get it.

Say you advance dist 50* in position:

To get 30* advance, the electronic modules retards (waits) 20*
To get 20* advance, the electronic module retards 30*
To get 10* advance, the electronics module retards 40*.

If you set distributor in 10* in advance. How does a module go into the futre and advance it 20* ? It can't.

You can't begin a spark before the magnetic (or optical) trigger happens. You can only do spark it at same time, or later on.

==========================

TB's have a fixed rotor position.

Now, the coil in plug hei's and many points distributors used weights and cams. The rotor position changed as rpms climbed to change the timing. Ths they where called mechanical advance. The magnetic pulse and energy from coil didn't change timing, the relationship of the rotor to the cap terminals did.


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