Mercruiser Inliner Swap Progress...165 Rebuilt I6 replacing the old 470

[WOEISMEIGOTTA470]

cant you go with a est distributor?

What do you mean EST? I've heard of HEI. I was thinking of getting an electronic dizzy from a 3.0L and converting it somehow with v6 guts...

 

[WOEISMEIGOTTA470]

Nevermind, EST is what I was looking into actually, just forgot what it's name (acronym) was lol.

 

[mickyryan]

would be easiest man and all you would need is one from a 6 cyl they made em if I recall and a coil and boom you in business

 

[WOEISMEIGOTTA470]

would be easiest man and all you would need is one from a 6 cyl they made em if I recall and a coil and boom you in business

Yeah, I like the idea, only thing is the one that I know made for a 6cyl is for the 4.3 V6, and the distributor shafts are different. Hence, I'd need to get two dizzy's use the 3.0 mechanicals, and the 4.3 V6 electronics, modules, cap, etc. Expensive lol. Been looking on ebay. Should work in theory.

 

[WOEISMEIGOTTA470]

Good looking float you got there man. Hope you get the spark knock thing figured out.

Thanks dude, it's getting there..

 

[mickyryan]

hmm I could have sworn that ok let me help you I just went through all this heartache and learned a few things , same module is used for 4 6 and 8 do not not get a marine one car wont work as car has to rely on ecm to work where as the module for marine has the advance built in also petronix sells a kit for your old distributor to get rid of points.
?Mercruiser: 811637T
?OMC: 3854003
?Marine Power: 483002
?Sierra: 18-5107-1
?GLM: 73190
?Mallory: 9-29800
you would need a pickup and a 6 cyl
http://www.inliners.org/ubbthreads/...34&PHPSESSID=04b53b6f76a70772d17baeec24a47a3b that guy did same as what you want/need to do.

 

[proshadetree]

If you have points check the dwell and the dissy shaft. Could have sworn that engine had pertronix in it. Also Davis Unified might have an HEI unit available for that engine. They can also curve to suit your needs.

 

[WOEISMEIGOTTA470]

Thanks Micky for those part #'s and confirming that the conversion can indeed be done. I'll look into it further but do have one question. I looked into the EST timing curves and it seems as if they might potentially be even more aggressive than what I have already.
Here's a Mercruiser document for setting timing on a 3.0L I found
http://www.boatfix.com/merc/bullet/90/90_15.pdf
It says that after setting initial base timing to 1*BTDC, then it should jump up to 12*BTDC and ..."At 2400-2800 RPM maximum (total) advance is obtained and should be 27 degrees BTDC, plus or minus 2 degrees."
Here is a snapshot of my timing at approx 1800RPM, the orange hash marks are ZERO. Each white notch represents 5 degress BTDC. So @ 1800RPM it's approx. 25*deg advance which is a lot I think too soon.

 

[WOEISMEIGOTTA470]

If you have points check the dwell and the dissy shaft. Could have sworn that engine had pertronix in it. Also Davis Unified might have an HEI unit available for that engine. They can also curve to suit your needs.

Thanks, yeah I see that Davis has a nice unit for the chevy 250 but not sure about marine rated. Also, correct I'm running pertronix - no points.

 

[mickyryan]

hmm yeah id think but then again anything over 1500 usually kicks in the advance if I recall but that does seem like you might have weak springs on the centrifical advance ?

 

[proshadetree]

I know Davis makes a great marine dist for BBC. I asume they have one for the six. If you can find an adjustable timing light and check total timing. Dont go over 34 degrees more like 32. Also check that fuel pressure 8 lbs sounds more correct. Mickyryan may be spot on with the weak springs.

 

[WOEISMEIGOTTA470]

Just found this, had trouble finding an advance curve online for the 3.0L which would be more ideal but you can see clearly that @ 1800 RPM my advance is a bit high. Considering I have my base timing set @ 4-5* BTDC, I have roughly 20deg. advance @ 1800rpm VS. what should be more like 6-13deg according to the chart below....

source : http://forums.iboats.com/forum/engin...gnition-system

 

[Scott Danforth]

If you're running a points dizzy with a pertronics conversion, the TBIV advance curves would not be the same.

A bit of wire would keep the weights from moving for a test.

 

[mickyryan]

that curve paper work isn't right anyways because with module shorted my 3.0 is at 1 degree with module not shorted and running 900 rpm I'm at 12 degrees and there is no centrifical advance on a est distributor or vac. also if not mistaken we don't go over 4800 rpm with the inlines

 

[mickyryan]

let me ask this are you getting any backfire at all ? because with that kind of predetonation I would think you would be popping and sputtering pretty bad if that was the case power would totally suck as well because you would be blowing the gas before you got to topdead center in essence fighting the engine if it was truly that far out of whack

 

[mickyryan]

looking back at picture I'm even more confused as to where your timing mark indicator is on the timing chain cover? it seems like you are missing it

 

[proshadetree]

That chart also will not work it is for a V8 not an inline 6. Start at 4 to 6 btc. If it runs good with no knock bump it up 2 untill the engine kicks back or knocks. Yours is knocking so bump it back 2. If it isnt poping out the carb on accelleration your ok.

 

[WOEISMEIGOTTA470]

Thanks guys. Yeah well I know the chart isn't at all right, but I do believe I'm too far advanced on the curve. It's ramping up too early. I'm ordering a spring kit to try changing springs out and seeing if that helps. Yeah its a bit confusing those timing marks but I know they are right. I made the notches myself and a little paint using a timing tape for the correct diameter of the harmonic balancer as a template. I verified TDC on the timing cover with a spark plug tool on the #1 cyl and a degree wheel on the balancer.

 

[WOEISMEIGOTTA470]

Did some more digging online, came across an iboats thread here that deals with the same topic:

http://forums.iboats.com/forum/engin...51#post5096951

In the above thread Don S. had posted the timing curve for the 165 which is helpful and says I should be getting between 14-19* NOT incl. initial timing, @1800rpms. However I also found a Mercury service bulletin posted on boatfix (link below), and Pg. 8 shows the Mercruiser 165 timing advance curve specs for the prestolite dist which @1800rpm has higher values of 20-24* (also not incl initial timing).
http://www.boatfix.com/merc/bullet/95/95_11.PDF

With the above information it looks like as if my distributor timing might actually be OK go figure (at 1800r), even if it does seem a bit steep to me. I'm going to at least try to plot the curve on my engine as a starting point before I mess with anything, and see how it matches up with the newly discovered graphs I found.

 

[mickyryan]

so is this all from that noise you been hearing? that led you to think it was timing?