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Aq151a engine swap question.

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Myfyn69

New member
We have a 86 sun dance by sun runner. It's a great boat but the engine is very tired and now barley runs. We have looked all over for engine rebuild kits with no luck, the marine shops around Oregon where I'm from can't seam to locate one either. So 2 question s can you use automotive parts is gaskets bearings what not? Or how do I know what size engine can bolt right in without changing the 290 outdrive that came with the boat? Any help would be great thank you!!!!
 
My main question is can one use automotive gaskets and bearings and rings if I can't source marine parts for a decent cost? The motor runs just only has 115-120 psi in the cly.
 
These are car engines and have a closed cooled system, so the answer is yes. The pistons are an exception, they are different size than automotive to compensate for the longer stroke.
 
Try a different comp guage. No difference? Spray some oil in the cylinders and see if the #s go up. Different guages usually get different results.
 
I was going to suggest to verify the valve timing, as the belt could have jumped one tooth or two. If OK, a leak-down test would tell you where the compression is being lost.
 
el_pescador said:
I was going to suggest to verify the valve timing, as the belt could have jumped one tooth or two. If OK, a leak-down test would tell you where the compression is being lost.
Click to expand...
+ 1

Camshaft and counter-shaft belt maintenance, and/or correct indexing, is often over-looked.

If you end up replacing this belt, also replace the belt tensioner.



.
 
Myfyn69 said:
Or how do I know what size engine can bolt right in without changing the 290 outdrive that came with the boat?
Click to expand...
While I'd not simply install an automotive engine, any of the Volvo Penta OHC engine flywheel covers (bell housing in the auto world) will fit the Volvo OHC engines.
The over-all drive ratio will remain the same between the Volvo or Volvo Penta OHC engines.

I'm not equipped to answer this, but if there's an auto version with an automatic transmission, the engine crankshaft will require the centering bearing for a Marine application.
Most in the Marine app are equipped with a ball bearing, but this is a carry-over from the standard transmission auto version.
The Marine application can actually use a bronze or brass bushing.
The single bearing PDS pilot nose requres this for centering.


BTW, if you have not replaced the PDS bearing, it would behoove you to do so.
The single bearing PDS can be removed from AFT for bearing replacement.


.
 
You might be opening a can of worms if you are considering rebuilding. That's what I'm currently experiencing. I'm in the process of rebuilding my 1989 AQ151 and locating parts is very challenging. To answer your question, yes, I believe you can use mostly automotive parts with the exception of the pistons, which you'll have to have custom made, the cylinder head (the rare 1000531 head used only in cars sold in other countries, and maybe a few other parts.

If you want to proceed down that route I can give you part numbers and sources for the parts.

DO NOT HAVE AN ENGINE REBUILT BY A CERTAIN REBUILDER LOCATED IN INDIANA (that shop has tied my engine up for more than 6 months with one "delay" after another) I don't want to release their name in the hopes that they can make good in the next few weeks.

If you can go with a few less horsepower you can use pistons for a AQ131 and a more common 1000530 cylinder head.

Good luck however you decide to go!
 
JimS88 said:
You might be opening a can of worms if you are considering rebuilding. That's what I'm currently experiencing. I'm in the process of rebuilding my 1989 AQ151 and locating parts is very challenging. To answer your question, yes, I believe you can use mostly automotive parts with the exception of the pistons, which you'll have to have custom made, the cylinder head (the rare 1000531 head used only in cars sold in other countries, and maybe a few other parts.

If you want to proceed down that route I can give you part numbers and sources for the parts.

DO NOT HAVE AN ENGINE REBUILT BY A CERTAIN REBUILDER LOCATED IN INDIANA (that shop has tied my engine up for more than 6 months with one "delay" after another) I don't want to release their name in the hopes that they can make good in the next few weeks.

If you can go with a few less horsepower you can use pistons for a AQ131 and a more common 1000530 cylinder head.

Good luck however you decide to go!
Click to expand...

The stroke in the AQ151 is longer than in the AQ131, so to install AQ131 pistons the crankshaft will also have to be replaced. But with a bit of luck he might be able to reuse the original pistons and that should make the rebuild easier.

The 1000530 and 1000531 heads are exchangeable, but the 530 has a much improved flow through intakes/exhaust. In either case I would also use the V cam from the AQ151 if the rebuild is to use the dual carb arrangement.
 
I'm very sorry about the delay guys I never got an email that said I had responses. Also I had spent a week in the hospital with the flu and a 106 degree fever. So I'm at the storage lot with the boat now and really wan to give it a go. The pistons and crank are still good it's the rings and bearings and gaskets I'm after the boat was low hours I believe 2000 but sat a really long time last year. It ran great at the beginning of the season after a tune up. Then developed an water leak from the exhaust bellows so we replaced that and the water impeller and seals. Took it out ran for about 15 minutes great shut it down to pull in a tuber and it started to back fire and die would not restart. Got towed In checked the carbs and cleaned them up replaced a few filters and hoses. BOUGHT a min Kota and mounted it to the back of the boat. Ran the boat in the driveway with water flowing 30 minutes ran great took it to the river dropped it in warmed it up ran fine got out into the middle of the clackamette river in Oregon city sputtered and died would not restart. Thanks to the min Kota we got back slowly but got back. Talked to the local boat place and he said the carbs probably need completely rebuilt but for the cost we should go to a single webber. We did the compression check as the whole season before it was loosing power to the point we couldn't tow a tuber almost at all. And that's all our boat is used for. I told him the compression numbers and he said its a bit low and most likely the cause is the head or valve seals and if I'm pulling the head I might as well put bearings and ring in the motor so when I go out this year I don't have to worry about it at all. By the sounds/looks of it these motors are really hard to get parts for. But I really hate to part with the boat. We only paid $350.00 for it and have about $200 in parts so far in the 2 seasons we played with it. We have a reputable machine shop out here in Oregon. Called ricks machine shop. He did the heads on my 1969 roadrunner a few years ago and just did the head on a 98 Volvo v70 wagon and it was great work.
Jims88 if you have an idea where to get the rigs and bearing I'd love that info. Sorry if this looks a bit funny I'm responding on my iPhone and can't really see the whole screen. Ill check it on the computer to figure out the other bearing that someone said should be replaced. Thanks for all your help and advice everyone!!!! The kids and I really appreciate all the help getting there tubing fun boat back going!!!!
 
Just an FYI on the 5% thing.
We'll see anywhere between 5% or 10% being suggested for the acceptable different between the highest and lowest cylinder pressure readings. However, this does not account for over-all low cylinder pressure readings.
IOW, we could see numbers well within the 5% high/low, but if the numbers themselves are low across the board, we have poor cylinder pressures.
 
I am not sure if the 240 turbo pistons would work, it would be interesting to find that out. But since according to Myfyn69 the current pistons are still in good condition, that should be a non issue. I still would suggest to go for a leak-down test and take it from there. If piston ring replacement is needed and crosshatch restored, cast iron rings will seal better and faster, but they will also drag more and wear faster than chromium rings. The secret for cast iron rings longevity is to clean the bores thoroughly before installing the rings.
 
So if I'm understanding this right, the rings and bearings the selfs from a 240 series Volvo automotive engine should work in the marine engine? That's would be very nice. I will look into how to do a leak down test. 1 to know how to do it and 2 to see where the loss of compression is coming from. Thanks guys for the Info. I will post any findings as I go.
 
I had to get parts from multiple sources because none of them had all of them. Here are the sources I used and liked.

These three are automotive sites for better pricing than marine
http://www.autohausaz.com Good prices, free shipping
http://www.volvopartswebstore.com Good Source for other parts
http://www.swedishautoparts.com also good, slightly higher prices

https://www.marinepartssource.com Best prices for marine parts

http://www.marinepartseurope.com/en/e-volvo-penta-359-AQ151C.aspx good source for schematics & part numbers

You need to find out if your main bearings are 55 mm or 63 mm (mine are 63 mm)

Volvo Part #
unless noted
Crankshaft Timing Gear1336927I replaced mine due to rust
Aux Shaft Timing Gear3507751I replaced mine due to rust
Head Bolt SetVictor Reinz 1306341
Oil PumpMelling M181
Oil Pump O-Ringneed 2418360
Auxilliary Shaft Bushings463360
Auxilliary Shaft Bushingsneed 2463361hard to find
Block Gasket SetElring 270679
Head Gasket Set876302or Sierra 18-2813
Main Bearing Set27090663mm
Rod Bearing Kit270136
Wrist Pin Bushing1346392please verifyor W0133-1641050
Engine Crankshaft Thrust Washer Set270471
Block Freeze Plug 40mm3531239probably don't need
Head Freeze Plug946779probably don't need
Head Freeze Plug955086probably don't need
Head Freeze Plug955088probably don't need
Bushing- fits in oil breather hole in block463362probably don't need
Sleeve- fits in oil breather hole in block415311probably don't need
Expansion Plug - Rear End Aux Shaft463905
Engine Camshaft Plug; Rear1336763
Please verify if these are the right parts for your engine, Volvo changed the parts over the years. I gave you more part numbers than you probably need but you will need other parts that are external to the block/head. I can help there too if you need it. Seems to be some confusion about the pistons. I'm quite certain AQ131 pistons WILL NOT WORK IN A aq151. The wrist pin to top of piston dimension is 3 mm shorter to accomodate the 6 mm longer stroke. Grinding the skirts on a standard piston won't help this. If you don't replace them than the point is moot. Also, Volvo changed the connecting rod from a skinny one to a beefier one in later years (probably not an issue for you).

Hopefully this will help.

Jim
 
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You sure the comp is really that low? What is the reading for each cylinder? Use a different guage? You say it starts? Then falls on it's face?? Or did I miss something? That sounds like a fuel delivery problem. I'd hate to see you go through all this just for a fuel pump????
 
el_pescador said:
The stroke in the AQ151 is longer than in the AQ131, so to install AQ131 pistons the crankshaft will also have to be replaced. But with a bit of luck he might be able to reuse the original pistons and that should make the rebuild easier.

The 1000530 and 1000531 heads are exchangeable, but the 531 has a much improved flow through intakes/exhaust. In either case I would also use the V cam from the AQ151 if the rebuild is to use the dual carb arrangement.
Click to expand...

I just noticed a typo. I meant to say in the original post that the 531 head (not the 530) has the improved flow.
 
Correction: The Block Freeze Plug 40mm I posted is wrong. I now believe the correct number is 968955.

I would have edited my post but apparently I don't have sufficient privileges to do so, or too much time has passed, or something else.
 
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