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AQ151 crank

poulrais

Well-known member
Joined
Sep 8, 2006
Location
Quebec, CAN
I have an AQ151 crank with the middle thrust bearing. I also have a 1994 B230FT squirter block with the thrust on #5 main. Is there way to machine the block or the crank so one will fit in the other or should I just try to find an AQ151/171 forged crankof a later year motor with the #5 thrust?

And yes I did search but couldn't find the answer to that specific question.
 
Aside from the thrust location difference the main journals are 55mm on a center thrust, 63mm on a rear thrust.
 
I have some oddball crank with the larger mains and the center thrust. I have the rear journal welded then machined to be a thrust surface. I haven't run this motor yet.
 
I think he's referring to the disc type (Welch) plugs used on earlier blocks. They can be tricky to install correctly.

FreezePlugInstalled.jpg
 
I think he's referring to the disc type (Welch) plugs used on earlier blocks. They can be tricky to install correctly.

FreezePlugInstalled.jpg

This...

And it's hard to install retainers on these because the flat edge around the plugs are thinner than on the automotive blocks.
 
I already have the Penta block from came the crank but aren't the freeze plugs design on these a little flaky?

I would think that it's a whole lot easier adding oil squirters onto the Penta block than it is to modify the crank for use in the later automotive block.

My only concern using the Penta block would be to make sure that the block has all the mounting bolt holes that you need for automotive use.
 
My only concern using the Penta block would be to make sure that the block has all the mounting bolt holes that you need for automotive use.

That's not an issue, they may be so rusted that it may not look like they are tapped, but they are.

My suggestion, run the penta block, and when you start getting power numbers where you're concerned about things like squirters, then do those mods/swaps.

I have a question though, what's the real world difference with center and rear thrust bearings?
 
That's not an issue, they may be so rusted that it may not look like they are tapped, but they are.

My suggestion, run the penta block, and when you start getting power numbers where you're concerned about things like squirters, then do those mods/swaps.

I have a question though, what's the real world difference with center and rear thrust bearings?

I think it's not so much the placement of the main thrust but the size of the mains. 55 mm for the mid thrust engines, 63,5 mm for the rear thrust.

So I found and bought another crank in BC that is rear thrust and well prices. I should get it next Tuesday.

Anyone needs an AQ151a block and crank? The block is in pretty good shape btw so I'll probably post it in the For Sale section this weekend.
 
I run a B21 without squirters, good heavens,omfg,SMH, and it hasn't blown up yet, well a few head gaskets here and there but the block has the same amount of holes as when it left the Volvo plant. I think I would have to get new pistons to use that crank wouldn't I? Or is that block taller? What kind of head was on it?
 
I run a B21 without squirters, good heavens,omfg,SMH, and it hasn't blown up yet, well a few head gaskets here and there but the block has the same amount of holes as when it left the Volvo plant. I think I would have to get new pistons to use that crank wouldn't I? Or is that block taller? What kind of head was on it?

I have the Penta pistons that came with that block and they are in very good shape. The block came originally with a 531 head. I may be able to source another 531 head. I don't know how much power the stock Penta rods can take though. They don't look that big. And I rechecked the block's tag and it's an AQ151b. I didn't clean the pistons btw. They came out like this. The oil ring isn't clogged at all.

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I will do some research, I have another B21 with M rods, need to see if they'll bolt in.

http://forums.turbobricks.com/showthread.php?t=24675

From the Penta FAQ:

Rod / Piston interchange
the AQ151 and AQ171 use the same 152MM long conn rods as the B230 engine, and use a 3MM shorter compression height (wrist pin to piston crown) to compensate for the longer stroke.
<table frame="hsides" rules="all" width="360"> <thead> <tr style="height: 2cm;"> <th title="Piston dimensions (mm) / Piston pin dimensions (mm)" colspan="2" align="center">
wNzM4ODkyNnM0MTNkZmQzMXk1NDE%3D.jpg

</th> <th title="Mounting of piston rings" align="center">
wNzM4ODk0NnM0MTNkZmQzMXk1NDE%3D.jpg

</th> <th title="Nominal diameter of cylinder" align="center">
wNzM4ODkzNnM0MTNkZmQzMXk1NDE%3D.jpg

</th> <th title="Piston article number" align="center">
wNzM4ODkwNnM0MTNkZmQzMXk1NDE%3D.jpg

</th></tr></thead> <tbody> <tr> <td align="center"> <table> <tbody> <tr> <td title="Compression height">Compression
Height
</td> <td align="right">36,7</td></tr> <tr> <td title="Combustion chamber depth">Combustion Chamber Depth
</td> <td align="right">3,2</td></tr> <tr> <td title="Distance between bosses">Distance Between Bosses
</td> <td align="right">25</td></tr> <tr> <td title="Total length">Total Length
</td> <td align="right">61,7</td></tr> <tr> <td colspan="2">
wNzM4ODk1NnM0MTNkZmQzMXk1NDE%3D.jpg

</td></tr></tbody></table></td> <td align="center">Total Length
Pin
23
x
65</td> <td align="center"> <table> <tbody> <tr> <td title="Ring type: Rectangular ring">R</td> <td title="Height of ring">1,75</td> <td>Cr </td></tr> <tr> <td title="Ring type: Taper-faced Napier ring">NM</td> <td title="Height of ring">1,75</td> <td>
</td></tr> <tr> <td title="Ring type: Coil spring loaded slotted oil control ring">SSF</td> <td title="Height of ring">3,5</td> <td>
</td></tr></tbody></table></td> <td title="Nominal diameter of cylinder" align="center">96,01</td> <td align="center">037 03 00
96 V 18</td></tr></tbody></table>
 
M rods are 146mm, not a bolt in solution. China Bay H beams however should do the trick. I just bought this B21 as a just in case I ventilate my current engine but 2.5L would be nice, I wonder what freights would cost from the great white North? Not gonna fit in a flat rate priority mail envelope but my Dad and his girlfriend travel up there frequently.
 
M rods are 146mm, not a bolt in solution. China Bay H beams however should do the trick. I just bought this B21 as a just in case I ventilate my current engine but 2.5L would be nice, I wonder what freights would cost from the great white North? Not gonna fit in a flat rate priority mail envelope but my Dad and his girlfriend travel up there frequently.

I can ask Roger-Dee as he just shipped 2 crates with a T6 and and T5 blocks and heads to Hank Scorpio who's on the West coast I think.

But if your relatives travel over here I could easily meet with them on the US or Canadian side.

If there's anything just shoot me a PM.
 
As shown above you can use the B230 rods. To get a stringer stock B230 rod you can use the later version from about 1990 and newer B230.

I have a spare set of 13mm rods from a 1994 B230ft squirter block. You can fit the Penta's stroker pistons to these rods?
 
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