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Chad242ti
11-11-2003, 07:10 AM
Hey guys, I thought I would share some stuff I found recently... The Volvo Penta AQ171 is a 2.5L DOHC boat engine. Here's a PDF file that list many of the parts for it...

http://www.lidingomarin.se/pdf/Volvo/SECTION%2003.PDF

Also note that the AQ171 was known as the 251A as well...

I thought this might be a helpful bit a of info for some of our crazier guys... I'm still thinking a 2.5L turbo 16V would be lots of fun. There are a couple of us t-brickers that are already involved in building this motor...


Also the pdf contains part numbers for both the V and A cams, as well as lots of other intersting tidbits...

mAydAy
11-11-2003, 07:29 AM
251 is some sort of similar engine with a 16valve head
I've never seen an aq251 but it appears to be a 16valve of some sort. the 251 was the same year as the AQ171A but shares parts with the AQ171C, perhaps it was the AQ171C before it was renamed to that?
*EDIT* Perhaps if I found my Volvo Penta repair manual it would tell me....

Chad242ti
11-11-2003, 07:32 AM
Just noticed that the PDF has a listing for the timing belt and the tensioner for a 16V. If I am correct, the AQ171 does not use the B234 block, it uses a the B230 block. So this would solve the problem of having to make you own... :-)

On the Volvo Penta site, the AQ171C and the 251A are the same engine...

http://www2.volvo.com/NR/rdonlyres/A23CE43B-775C-4A41-A67B-216F333FB010/0/251ADOHC_SP_1990_en.pdf

mAydAy
11-11-2003, 10:32 AM
251 is the carburated version of it...I see. Now it all makes sense

Boosted2003
11-11-2003, 11:25 AM
do all aq171c cranks 63mm main bearing?

turbobrick211
11-11-2003, 07:50 PM
Okay, what would it take to make this a sticky subject? I think that there is quite a bit of valuable information that could be gained here if we stick to it. I believe that there are a number of people on this list (including myself) who would be interested in adapting the "marine grade" Penta stuff onto our performance motors. I would love to stuff a stroker crank into my project motor I have going. I would love to look into other parts that might just bolt in with minor modification that might provide more durability and reliability.

Please keep this thread open, and lets see what we can find out about cranks, rods, pistons, heads, cams, oil pumps, and any other goodies that we can source to fit our cars. Let the findings continue!!!!

Regards,

the poi
11-11-2003, 08:14 PM
I think the only thing keeping a lot more people from doing this kind of engine buildup is sources. If we could just find a semi-reliable mehtod of obtainin these parts, it would definitly be more popular...ive yet to see a boat junkyard tho........

mAydAy
11-11-2003, 08:20 PM
We'll see. Next weekend I am going to go and talk to some friends in the sterndrive business that work on Volvo Penta's and see what kind of sources I can get. I think I can find atleast a few aq171's

I've got another question....Since the aq171c is a stroked b230, and the aq171a was something similar but before it, any chances its perhaps a stroked b23f block?

davidmacq
11-11-2003, 08:28 PM
http://forums.turbobricks.com/viewtopic.php?t=9434&highlight=
:wave:

Boosted2003
11-11-2003, 08:52 PM
im got a aq171c crank for 80 bucks since doug sold my 75 dollar ebay deal lol

Pennybridge Pioneer
11-11-2003, 08:58 PM
...ive yet to see a boat junkyard tho........

you need a snorkel... :grrr:

mAydAy
11-11-2003, 09:08 PM
ugh, not that thread....thats the one where i am an ignorant POS :oops:

davidmacq
11-11-2003, 10:13 PM
I was told aq151 was a candidate along with the aq171.

Boosted2003
11-12-2003, 01:20 PM
i think it is thats what paul used for his stroked motor

ZVOLV
11-12-2003, 02:48 PM
What are the drawbacks of going with the 2.5L?

A boat mechanic I talked to said the 2.5L would ping like a mofo.

Do you have to use the entire engine or will just the crank work on the b230? What about the head? Will the b230 head work on the marine bottom end.

The mechanic said that the boat engines are set up for low end torque, but car engines are desgined to have a bigger power range.

Dont get me worng, i want the 2.5. I was on the phone with a guy today regarding the 3.0 four cyl volvo (chevy). :twisted:

davidmacq
11-12-2003, 03:43 PM
Not sure what he meant by pinging... 2.5L is considered the max size for a 4 cylinder I have read. Get lots of vibration or something the larger they get. Perhaps he meant that.

Main thing with a marine engine is that they are under constant load. No gears...?

The 2.5L penta engines are not considered big or powerful in the boat world though. Just very reliable.

From what I understand there aren't any downsides really. Maybe that you would need megasquirt or something to manage it??

MikeHardy
11-12-2003, 03:48 PM
the porsche 968 got upto 3L but i think they were running balance shafts like the B234F to cancel out the vibration

Boosted2003
11-12-2003, 05:03 PM
the porsche 968 got upto 3L but i think they were running balance shafts like the B234F to cancel out the vibration

yeah but if u balance and blue print it wont have much trouble after every done corectly

CNGBrick
11-12-2003, 07:19 PM
[quote:7d8b13cc13="ravennexus"]the porsche 968 got upto 3L but i think they were running balance shafts like the B234F to cancel out the vibration

yeah but if u balance and blue print it wont have much trouble after every done corectly[/quote:7d8b13cc13]

You can't eliminate all significant vibration sources in an inline four engine without balance shafts even if the engine is perfectly "blueprinted and balanced". The 968 uses the Mitsubshi-patented twin balance shaft system.

RT

aussyvolvo
11-26-2007, 09:46 PM
I dont get it.... the engine looks exactly the same with different add ons... wouldn't you be able to just get that engine and put all the pullies, pumps, intake/exhaust, ms, clutch/flywheel stuff and mounts for a normal car and just use the penta? wouldnt that make it easier instead of rebuilds?

I wish I knew were to get this stuff second hand in south aus :P

MrBill
11-26-2007, 10:12 PM
I dont get it.... the engine looks exactly the same with different add ons... wouldn't you be able to just get that engine and put all the pullies, pumps, intake/exhaust, ms, clutch/flywheel stuff and mounts for a normal car and just use the penta? wouldnt that make it easier instead of rebuilds?

I wish I knew were to get this stuff second hand in south aus :P

this thread is very old and pretty much wrong
171 and 251 are DOHC redblocks with b230 blocks and 2.5 cranks
Im pretty sure 251=171c
171b and 171a are the older non-desirable smaller cranks etc

500dollar744ti
11-26-2007, 10:32 PM
holy ****ing thread resurrection batman!

aussyvolvo
11-26-2007, 11:10 PM
soz I was told to use the search function more, but forgot to check the date :P but whats wrong with bringing things back to light?

so if you got the 171c penta, would you be able to jsut fit it ect..? also, would you be able to use the 16v head on a normal engine, cos the 16v is realy realy scairse here.... for that matter so is second hand penta engines :P but I know a penta distributer, so it will be easier to get penta than the actual 16v out of a car

MrBill
11-26-2007, 11:20 PM
penta prices are hilarously overpriced.
take out the 171c crank and pistons, place in 90+b230 block, profit

Edit nm, you want the head, someone here can find you that head and ship it over to you cheaper i bet

Mueller
11-26-2007, 11:21 PM
soz I was told to use the search function more, but forgot to check the date :P but whats wrong with bringing things back to light?

so if you got the 171c penta, would you be able to jsut fit it ect..? also, would you be able to use the 16v head on a normal engine, cos the 16v is realy realy scairse here.... for that matter so is second hand penta engines :P but I know a penta distributer, so it will be easier to get penta than the actual 16v out of a car


read this page a few times....

http://wwwrsphysse.anu.edu.au/~amh110/16V_Folder/16_valve_turbo_volvo.htm

not easy or cheap, otherwise everyone would be doing it....

AuzVolv
11-26-2007, 11:30 PM
All Aq171 cranks are the same. And they are the same as AQ251. Volvo Penta changed the designation on all engines to represent their capacity rather than output i.e. 171 = ~170hp and 251 = 2.5litres
Aussyvolvo: there is also a AQ151 = 150hp and AQ250 = 2.5 litres
Like I said on your earlier thread these are few and far between here down unda, but do ask your local dealer - people are always replacing them with V6 chevs or diesels. I've found they regularly come up in the UK for about 500 kwid!

MrBill
11-26-2007, 11:33 PM
no they arent all the same
the 171a and 171b are like k-blocks or something terrible.

- Small
AQ131A, AQ131B (cast)
AQ151A, AQ151B
AQ171A, AQ171B
-Large
AQ131C, AQ131D (cast)
AQ151C, AQ151D
AQ171C, AQ171D
sp 230 (all) (cast)
sp 250 (all)
sp 251 DOHC (all)

AuzVolv
11-26-2007, 11:33 PM
PS the AQ151/171, AQ250/251 use a B230 block and I'm not sure how this differs to a B234 block.

AuzVolv
11-26-2007, 11:37 PM
What ever you say MyBill, but my parts manual list all components as the same part numbers - A through to C!

AuzVolv
11-26-2007, 11:40 PM
Sorry my mistake MRBill you are correct the part No for C cranks are different to A cranks. Appologies.

aussyvolvo
11-26-2007, 11:52 PM
sounds cool....... but is that 500au? including shipping? ect? on ebay?
and the block had a few diffs, like the way thigns like pumps are atached and the cam belt tentioner and ballencers (but most are bolt ons)

AuzVolv
11-27-2007, 12:35 AM
sounds cool....... but is that 500au? including shipping? ect? on ebay?
and the block had a few diffs, like the way thigns like pumps are atached and the cam belt tentioner and ballencers (but most are bolt ons)

More like $1000 AU! You can try www.boatsandoutboards.co.uk for some. I'm not sure about the belt being square or round tooth maybe POIK can confirm! every thing esle should be the same.