BB 454 Gen IV (Mark IV) - Pertronix distributor

Hi first thanks for accepting me in this forum.
I'm Italian and owner of a boat with 2 x BB 454 Gen IV (Mark IV) 1973 engines, Actually i'm rebuilding it and i got 2 new blocks remanufactured from USA plus all the other necessary parts (like the new distributors in this case).
I did buy 1x Pertronix D209800 and 1x Pertronix D200810 (1xSTD and 1xREV rotation ). Now the mechanic here is stopping on the Pertronix settings ... they have a doubt on the spring and limiters for the maximum mechanical advance (none 12°/blu 16°/red 20°) to use for this model of engines.
We saw from documentation that the defualt is the silver spring as per attached picture (extract of installation manual).
From orginal specs the blocks are for 4.500 rpm and are equiped with 4BBL Rochester.
Can someone help us ? Is the default silver spring the correct one to use ?
in this case wich limiter 12°, 16° or 20° should be used ?
really thanks if someone can help me. Isn't easy task .... Attachment 67220
Nick.

Welcome Aboard CHR... (pun intended!) Nice to see you here.
The default (Silver) spring will work fine. As a base setting. If the fuel available to you can support more timing, step up to the next spring.

Thanks for the answer 34_40
do you have opinion on the limiter ? 12°, 16° or 20° ?

I'm being cautious... I'd say start small. Again, I don't know the fuel that is available.. Then work up and play it safe.

Quote:

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Originally Posted by 34_40

Welcome Aboard CHR... (pun intended!) Nice to see you here.
The default (Silver) spring will work fine. As a base setting. If the fuel available to you can support more timing, step up to the next spring.

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Quote:

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Originally Posted by garzeln

Thanks for the answer 34_40
do you have opinion on the limiter ? 12°, 16° or 20° ?

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Quote:

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Originally Posted by 34_40

I'm being cautious... I'd say start small. Again, I don't know the fuel that is available.. Then work up and play it safe.

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No disagreement with Mike's (34_40) approach. It seems to me that if you have your base timing set at 12°, which I believe would be reasonable, then with your 12° limiter your total timing will only be 24°; with the 16° limiter it will be 28° all in; and with the 20° limiter it will be 32° all in which is still a pretty conservative total timing for those engines. Like Mike says, depending on your local fuel quality starting low is safe, but I would expect that you'll end up with the 20° limiter once you have the engines all dialed in. I believe that's the same thing Mike's saying, too.

just remember that initial timimg is in crankshaft degrees and distributer timing curves is driven from camshaft--------whatever the degrees talked about in the distributer is doubled at the crankshaft---


12* crank plus 12 * dist equals 36*

Quote:

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Originally Posted by jerry clayton

just remember that initial timimg is in crankshaft degrees and distributer timing curves is driven from camshaft--------whatever the degrees talked about in the distributer is doubled at the crankshaft---


12* crank plus 12 * dist equals 36*

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Garzelin,
While Jerry is 100% correct in terminology, to be clear to you since you’re coming to us from Italy but having to communicate in English:
When your Pertronix instruction sheet lists values for your ignition timing they are referencing the degrees of advance, or the limits to the degrees of advance stated in crank degrees Before Top Dead Center (BTDC), as seen on the harmonic balancer with your timing light. You can check this by setting your initial/idle timing at 12° BTDC, install your 12° advance limiter and with your engine running increase your RPM while watching your timing mark with your timing light. You should see your total advance limited to very nearly 24° BTDC.

I hope that this helps you understand your instruction sheet better, and welcome to the forum, by the way.

Hi all, thank you very much for the feedback really appreciating.
Rspears you got perfectly the problem of the language barrier ... english plus technical ... **):CRY:**):CRY:
in the meantime i found an extract of the service manual (attached). If i'm correct for the CH350 the original degrees should be 28°-31° with 10° BTDC.
so if my understanding it's correct i should use the RED limiter at 16° and this should be safe correct ?
if you see different just please let me know and i'll communicate to the harbor people.
Here the problem is that there are not machanics knowing this engines ... today they are only box checking ... they plug the test and the box is telling them what to do.
you can't imagine how long was taking me to restore those 2 engines (will post a couple of pictures).. all parts from USA (inclusing the 2 blocks) and a lot of study by myself.
thanks in advance, ciao.

Attachment 67224

Here where we are:

Attachment 67225Attachment 67226

A great looking pair... and as usual, Mr. Spears hits the nail on the head.
But for the break - in period and for the initial tune-up, I'd say be conservative and run the default spring. I doubt you'd feel the difference between setups imo.

With the language differences---------do be aware that if in fact your engine is reverse rotation and that the reversal is not done in the gear box-------the timing marks on the front crank hub will go in opposite directions from the notch-------and the distributor drive gear will be reversed so that the oil pump still turns the correct way---

There may be issue with water pump not flowing water correctly thru engine

spark plug wire location in distributor cap

starters won't interchange

what rpm do you cruise boat at??? On my Sea Ray with twin 454s I usually ran around 3000-3300 at trimmed out speed

Quote:

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Originally Posted by garzeln

Hi all, thank you very much for the feedback really appreciating.
Rspears you got perfectly the problem of the language barrier ... english plus technical ... **):CRY:**):CRY:
in the meantime i found an extract of the service manual (attached). If i'm correct for the CH350 the original degrees should be 28°-31° with 10° BTDC.
so if my understanding it's correct i should use the RED limiter at 16° and this should be safe correct ?
if you see different just please let me know and i'll communicate to the harbor people.
Here the problem is that there are not machanics knowing this engines ... today they are only box checking ... they plug the test and the box is telling them what to do.
you can't imagine how long was taking me to restore those 2 engines (will post a couple of pictures).. all parts from USA (inclusing the 2 blocks) and a lot of study by myself.
thanks in advance, ciao.

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Garzeln,
Your two engines look great! I applaud your efforts to see this project through in Italy, with all of the problems dealing with not only two USA engines, but Marine Engines which bring another level of "issues" and understanding. I'd say your understanding of the timing is correct. With an initial/idle timing of 10°, the RED advance limiter at 16° should give you total timing of right at 26° which is a safe, conservative number not knowing fuel quality, etc. Once you see how it does, and see that it doesn't show any pre-ignition clatter or detonation knock at Wide Open Throttle (WOT), you can try the 20° advance limiter which will put you at 30° total timing, just below the maximum listed in your manual. I'd say you're clearly on the right track.

Not to confuse you, but once you have verified your fuel quality, tune, and completed your break in of these engines another way to approach the timing is to select the advance limit that you want (for example the 20° mechanical advance), and then with your timing light rotate the distributor to set the total timing at the desired value, say 31° in this case, snug down the distributor hold down and then see where your initial/idle timing lands. Just another way to get to the end result that you want.

Looking forward to hearing how your initial startup goes, and then some video of the boat screaming across the lake!! Ciao!!

You're right engine is 1xSTD rotation and 1xREV rotation.

the blocks i used Promar Engines (they have Marine offering) --> Patterson New Jersey
I found the new starters at ARCO Marine (1xSTD and 1x REV) --> Arco Inboard Starter P/N 50137 and Arco Inboard Starter P/N 50138
Fuel Pump are Holley --> Holley Mechanical Fuel Pump Chevy BBC 396 454 110 GPH 6.5 to 8 PSI 712-454-11
all ignition are Pertronix --> Coil, distributors and 8mm wires
Carburetor --> Rochester 4BBL remanufactured
water pumps engine --> found 454 bi-directional water pump --> it works both directions

raw water pumps --> the 2 out of the engines you're right need to play attention on this --> those are the originals but i need to use the right one for the engine rotation.

will post first start ... we're not far away now ... and summer is now approaching

No Lake .... but Seaside !!!

Nick.

This is the project:

Riva Summertime 34 1974 all original interiors - instruments - evrything original to findAttachment 67232Attachment 67231Attachment 67233Attachment 67234Attachment 67235

2x350 Thermo Electron (then acquired by Crusader) --> 1973

before restoration was best range 21 knots at 3.100/3.200
saw the 31 knots at 4.200 (but gallons per hour .. nightmare)

Use the copper colored springs so advance all in at 2400rpm and the 12* limiters. Set timing with engine running at above 3000 rpm to insure that it will be total advanced at cruise and you can then check at idle to see what the initial timing is for reference.
Then you can also vary timing at idle rpm to see where it idles/low speed opt ( docking manuvers ) and vary either/both settings for best settings--

Seaside? Genoa? I could maybe put a 1/2 wrench and a spark plug socket in my bag and ??

Seaside Tuscany --> Exactly Castiglioncello --> 32 nm from Elba island - 30 nm Capraia Island ... :):):)

Great Pics. You could live on this thing, its gorgeous!