View Full Version : Penta AQ151 Crank

07-07-2003, 07:42 PM
Where can I get the same crankshaft that Paul Erickson from MVP uses? I've looked, but I'm having no luck.


07-07-2003, 08:14 PM
Where can I get the same crankshaft that Paul Erickson from MVP uses? I've looked, but I'm having no luck.


you get it from a boat with volvo penta engine.

07-07-2003, 08:19 PM
And not just any Penta, since they are popular in 2.3 liter displacement.
Maybe you could contact a dealer and ask what years they were available and what the HP designation is.

07-08-2003, 12:56 AM
I saw a AQ151 crank going for 54 bucks on ebay.. and I didn't buy it :-(

07-08-2003, 01:13 AM
i almost bought a AQ125 ... that would have been bad...

07-08-2003, 01:19 AM
maybe these guys?:


Also, Tony @ Verrigini (spelling?) Marine (check google or Switchboard.com) has a superb reputation for new parts, and might know where to send you for used

07-08-2003, 11:54 AM
If you have a B2X (as opposed to B2XX) there one going on ebay at the moment.

start running people!

07-08-2003, 12:31 PM
Nope there was never a stroked b23 crank from penta, nor was there ever an AQ 151 in that series.

I could only find one auction- the one where the guy wants to include the main caps with the crank (WTF is he thinking??). That'd be an 80 mm crank.

07-09-2003, 04:37 AM
I'm always amazed how little info is available on this subject, when so many people are after one of these cranks. If this site is correct http://www.eurofritid.no/Volvo/Bensin/Default.htm then we're all after an AQ171 crank, not an AQ151. I've heard that the AQ171 is a 2.5, with a 16v head and twin carbs of some sort.

Also, don't we need matching rods to use one of these cranks? That's something I haven't heard people talk about very much.

Aussie Mike
07-09-2003, 05:53 AM
The B230 motor was available as a penta marine engine in 3 variations. The AQ131 was a B230 with a single carb. The AQ151 was the stroked B230 with the 86mm crank making it a 2.5 litre running twin carbs and the AQ171 was the stroked B230 with the 16 valve head also running twin carbs. I have the Penta manual on these motors and they all do exist. It won't be that easy to find them however. There is also a Super Marine block which is very similar to the R block. It can be bored up to 99mm successfully. There was a guy running a sprint car of some sorts with the Super Marine block bored to 97mm with the 86mm stroked crank. It had a 14:1 compression ratio running on methanol putting out 340 Horsepower and apparently in a class of its own. I enquired about a Super Marine short motor which was available new a few years ago for $4,000 US brand new. Someone might have to try to see if they are still available new if they want one bad enough. I am not sure if they had provisions for the oil squirters though.


Aussie Mike

07-09-2003, 06:38 AM
my parents' sailboat has a single-cylinder 0.9L penta engine in it... guess that doesn't help anyone... lol

it moves the boat just fine thank you! (albeit it sounds like any other single-cylinder engine...)

07-09-2003, 09:17 AM
like Aussie Mike, I have a manual or two, and yeah, rare though they are, these motors exist, and the parts fully interchange.

The con rods are stock b230, and they and the crank follow the same width changes and main diameter & thrust bearing location changes as cars, so it's a late motor one would want. The height difference is taken out of the pistons, not the rods. The pistons are very slightly dished, but with the extra displacement, produce more compression than you'd want for a turbo motor. Any piston bought from a salveage yard with a crank would mostly be used only as a sample for a custom one- ie you'd mail it to JE, Wiseco, Ross, Diamond, etc and say: "I want this with a deeper dish, oval shaped, and principly under the exhaust valve. "
I believe Chandler might have been the guy I exchanged PM's with about this. (??)
And again, there are no factory, Penta, b23 series stroker motors- the AQ145 is the highest output old style motor and it did so on stock displacemnt, a K cam and lots of compression- almost identical to a Canadian b23E, but with carbs. You can, however, make a b23 aftermarket stroker crank by offset grinding the crank, as DaveBarton has done, as I have done, and the infamous Topi @ trs has done. Apparently someone in vintage racing has a motor built with this concept (based on the b20) and is lying about that fact... I received an odd email on the subject last year. They are out there and work. To me this is easier than seaching out a marine crank. Depends on how comitted to the b230 block you are- its additional and/or relocated stud bosses for A/c and a few other things.

07-09-2003, 10:01 PM
I have a friend here with a stroked b20 (offset ground) in a p1800 and he loves it. It's his weekend toy, so it doesn't see many miles.

No comment on the penta stuff. My information is so secret, I don't even know what it is yet. :rofl:


07-10-2003, 05:33 AM
Ahh.... interesting, thanks guys for clearing up a few things. If the pistons are what changes between the marine and automotive engines, and they are only available dished, then they're no use to me. I'm staying NA and want to retain the flat top B23E pistons for a 10:1 CR.

I also didn't realise that these cranks were only available to suit B230 blocks.

It was worth looking into at least.