Big Ass O-ring and 6 bolts ......

Gotcha, I was thinking newer omc/volvo style drive.

Alright, alright, alright ….
I was totally brain farting on this until I sat down with what I had and the paperwork on each boat I’ve done (keep all records of what was bought for on each boat I rebuild for future reference).
Like Fixx said, this is for a Volvo Penta. Before I would go crazy like switching to a different motor then the one that’s completely built for the boat I would have had to replace the bellhousing. They do make them for 14” flywheels but the cost is insane and something I’m trying to avoid after this long and expensive Donzi rebuild.
As for modifications, there is no way to build a bellhousing to block spacer big enough or anything else to get around the flywheel issue without pushing the motor to far forward or changing to many thing so it would not be cost effective (unless I owned a machine shop) then just replacing the expensive bellhousing. So yes I could have gotten a hold of a shop that would cut a custom wheel starting in the 5 or 6 hundred dollar range for a “single pc seal” or for 7 to 8 hundred I could buy a bellhousing for the larger flywheel or figure this ***** out because I’ve done this before. The only difference this time is it’s a Gen V motor. But I’ve used Mark IV flywheels on Gen V’s before but they were 14” flywheels. This all has to go full circle.
Ordered this one off of ebay. http://cgi.ebay.com/ws/eBayISAPI.dll...m=201154312655 Not so worried about having super high dollar big name flywheel anyway. I’ve never seen one “fail” in a boat no matter how cheap it cost. Not like it has a clutch hitting it or anything and I figure once they come back from the balancer it will be as good if not better than anything I can buy. Also last time the motor was rebuilt it was all balanced so I want the new flywheel to match the old so anything off the shelf would had to be balanced no matter how much it originally cost so….
Now that I have the new flywheel, for the record on 454 and BBC flywheels in general, the bottom line is this, there is no difference between any of them besides clutch size and balance. The ring gear may stick out or in a couple mm’s from the block but that’s it. A big block Chevy neutral balance flywheel is a BBC neutral balance flywheel, same exact flywheel for one of two piece seals. Weight on the crank flange or not they are still are all the same.
454 (external balance) flywheels, there is a balance difference between the Mark IV and the Gen V, VI. You will only find 153 tooth flywheels for Mark IV in the aftermarket today so all of them will have to be rebalanced for later motors. I have done this a couple times before and all they had to do was drill the new wheel a couple spots and not add metal ($$$) being the 4, 5 and 6 are that closely balanced out of the factory. If you are building a motor you are having it balanced anyway.
Small block and big block V-8 flywheels do not interchange. I have to add the exception of an older small block flywheel which I didn’t have in stock. The later 1pc seal SB flywheels will not fit on a Big Block Chevy. The bolt pattern is different and the center hole is not big enough to fit on the BBC crank. This also leads me to believe contrary to almost everything I have read on the net the only flywheel change (besides some small balance changes for the external motors) that Chevy ever made was to the 1pc seal small block only. Nothing to do with BB at all and all the listings for BBC flywheels on summit and jegs, etc, etc should say for 1 or 2 piece seal cause there is no difference. And with the difference balance flywheels, the one I bought the weight just screwed into the backside of the flywheel. How hard would it be to offer different weights for 4, 5 or Gen 6 motors if anyone who sells flywheels is listening? Lol.
But really this easily could have been a stock Gen VI replacement of a Mark IV, Volvo Penta power plant. There should be a “off the shelf” for under a 150 bucks, 153 tooth flywheel for the Gen 5 and 6 on the market. That 50% more than the average cost for a stock replacement and there’s still nothing. Someone needs to recognize… Lol.

RAM does, "0" bal. I believe 4 or 5 from 10 lbs up to 30 lbs.

ok, if 2 piece small block flywheels fit all bbc bolt patterns, then there should be zillions of 305-307-350 clutch flywheels avail on craigs for 10 bucks that could be balanced to the motor. heck i have several in my garage here in s. jersey. i believe the reason a pre balanced small flywheel for gen 5-6 bbcs is not avail is there is virtually no market for them. the stuff that only fits small flywheels was obsoleted 30 years ago.

See that’s just it, I didn’t have a 2pc small block flywheel to check so I’m not sure if they will fit or not. After all the research I’ve done on this crap I wish someone had one (confirmed it came off a small block) and tried to put it on a BB just to wrap this thread up with the right answers because the web has it all screwed up. After reading thread after thread on the interweb you would think there was no option for a small flywheel on a gen 5 and 6 big block. That is wrong. Flywheels for BB Chevy are no different regardless if the crank is 1pc or 2pc and only matters with external bal motors because of small weight differences on the bob. For that matter if you were just doing a stock job you could use the neutral flywheel and one of those aftermarket weight plates (I forget what they are call but jeg, summit, etc carries them) that bolts on when you put the flywheel on.
The situation I was in was in basically saying that the bolt pattern from 4 and 5 and 6 were different meaning there was no flywheel that would fit, period was not true and I’m sure has screwed other people up. Rebalancing a flywheel is nothing to do compared to trying to find one that is nonexistent. Been down that road before finding one of these 153 flywheels for a Chrysler 360. Did that a few years back. Took a year locate one.
One thing about the small block flywheel though (except for the 400) and a 454, you really don’t want to start off with a neutral balance flywheel for an external balanced motor. The balancer will have to add weight and that’s when the money adds up for a balancing job. So any weight (in the right general area) is a help even if the weight is not just right. I also have to say that if you looked at the 2 flywheels (mark 4 and gen 5) it looks like the only difference is the bob is shifted about 2 degrees. When I was a kid I would have slapped that dog on there and ran it. Wish I would have to find out but not stupid enough to do it today to find out knowing up front there is a difference.
As for no market I have to disagree. There is an insane number of Volvo Penta’s out there and there has to be more than a few people that at least thought about replacing their tired small block with something newer and bigger. Just like I’m doing with this 1976 Donzi 18. VP’s are good to 500+ hp. I have this Gen V 454 that should be an honest 375hp without over building it (pretty tame really), Once you start swapping parts like the aluminum intake and aluminum exhaust there will be almost no weight difference between it and an all cast iron small black. I’ll take a same HP tame BB over a hopped up small block any day. I’m not saying they should build a foundry or anything to make these flywheels but you would think there would be more options than some guy in Maryland figuring it all out. Like I said there is absolutely no difference in the BBC neutral flywheels except for the listing on about every site that sells flywheels and even the external bal flywheel is an easy fix.
The main reason I post all this is to help someone in the future sort through this mess. I know a lot of you guys have long since moved past Volvo Pentas and have Brovo 27000000’s, Kevlar, anti-gravity, surface drives with after thrusters on the back of your boats but some of us still do it old school. I mean honestly the latest Mercruiser drive hanging off a 1976 Donzi. Something just not right about that. lol

I need a pair of the Kevlar, anti gravity, surface drives with after thrusters for my Magnum. I think if I use the right paint they will look like old volvo drives.

Ayuh,.... How ya doin' f_n,..?? Long time no see,....

Atleast ya got past the ole Dodge motor,.....

I'm sure you have something in the back of that shop Tom that Joe is not telling you about. lol


Shhhhhhh ..... The new owner is around here some where. lol
4 or 5 years back still having it sitting in the corner of the garage I basically bought a whole 360 motor off of ebay and just used the good part from my old motor and built a pretty bad ass motor out of the two. Just not a fan anymore when you factor in the money and availability of parts compared to Chevy.
Again nice to see you outside of iboats. You don't know how many times I've wanted to go there and talk to DonS about a Volvo.
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Ayuh,.... I'm still at iboats,.... Ya might already know, but Don past away alittle over a year ago now,....

My go to guy for Volvos is now Rick, aka; Ricardo, over at marineengines forum,...

Good Luck, 'n Good seein' ya,.....