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wanting to swap out my AQ170 for a newer motor.

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kevinmi

Contributing Member
Hi guys. I have an old bayliner liberty (1976, aq170,aq280). I had all the glass work redone. transom, bulk head, stringers.. the works. My problem now is the motor. Everytime it breaks, it becomes a treasure hunt for me to find the parts/ppl willing to work on it. I love this boat. It fishes awesome and i just about got it the way i want it, but if it keeps breaking down, its gonna break me. Im in the process of converting the points to electronic, but i know its only a matter of time before something else breaks. Between the 3 solex carbs and the 10 different distributors that bosch made for this model, im pulling me hair out.
To make matters worse, in my exploits of rebuilding this boat, i bought a second penta 280 outdrive as a spare. So now i have a boat that is glassed in for a 280 and a spare to boot and a motor i cant get parts for and cant get anyone to work on.
Does anyone know which motor (if any) will bolt up to my outdive? It would be nice not to have to change the mounts but thats an easier pill to swallow than the bell housing and ratio stuff i know nothing about. any info would be most welcomed. -kevin, salmon fishing in michigan (yes some ppl still are doing it)
 

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Afraid there would be some changes in order to put in a different engine. For a V-8, you'll need the V-8 exhaust Y pipe and possibly a different transom shield with 2 relief ports. As you mentioned, the gear ratio is different so you would need to change the lower end or at least the lower gearbox and the matching gear for the vertical shaft. Of course, then you have the issue of motor mounts and electrical.

If you're interested in keeping your setup, I stumbled across a freshly rebuilt 170 at a local mechanists shop. Shipping costs from here to Michigan won't be pretty but at least that's a possible option. I have no idea if he wants to part it out, he just said that it's sitting in his shop and he wants to get rid of it. I'll send you some contact information if that s the route you want to go.

By the way - really nice looking boat!
 
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Kevin, I beleive that this would be a wise move to rid yourself of the 170.
As you may have learned, the exhaust manifold alone can break the boat bank.
Good news is..... this is a saleable part for you. e-Bay, for example.

As for your drive, transom shield, etc. I've done many of these conversions.
Here are some suggestions, and BTW, feel free to contact me if you need help.

Transmissions: all in this series are of the same reduction ratio... so no issues there.
You will find two PDS splines being use.... course and fine, of which may affect your female drive shaft yoke only.

Intermediate housing: again, this will interchange with any in this series.
(note that re-shimming is imperative when changing any of these components from one Intermediate housing to another)

Transom shield: ideally you'd go with the double exhaust relief shield and the large double relief Y-pipe.
These shields are now $3,000 + from Volvo Penta, and are becoming more and more difficult to find used and in good condition.
You can stay with the single exhaust relief shield, but you will be limited to the use of 3" exhaust and the AQ 200B or AQ 225B Y-pipe.
They are also becoming hard to find, but it can be done. If you find one... grab it!
This also limits you to the 3" exhaust manifolds, however, the BARR universal center-rise, and a few others will work just fine.
FYI, the 3" exhaust, while not ideal, is not a deal breaker, IMO.

Lower unit ratio: there is no substitute for a correct over-all gear ratio, period!
The 170 will have used the 1.89:1 over-all ratio. This ratio is not usable for the V-8.
Some 4.3L V-6s.... perhaps.
For the V-8, the 1.61:1 must be used.
Again.... re-shimming above the vertical shaft bearing race must be done.
(I suppose that you could use the 1.89:1 temporarily, but I'd not buy any props for it... not until you find a 1.61)

Fywheel Cover (aka bell housing in the automotive world): This will need to be for any Volvo Penta GM V-8's.
Whatever you do, replace the PDS bearings in this cover. Trust me on this one!

Engine mounts: these will need to be GM V-8 specific, and must mate to the engine stringer towers at the correct elevation. Not that hard to do.

F/C to Transom Shield rubber cushions: At least the FWD-most rubber ring will need to be new. This is the ring that does the sealing at this area.

Sea Water pump: Best to use the Johnson or Jabsco crankshaft pump.
These rarely fail, and offer easy access to the impeller, etc.

This boat was available with the V-8 if memory serves me.... so there should be no issues re; hull attitude, etc.

Have fun.... and enjoy the swap. :D

FYI, try to keep your drive all the way down and straight forward. This prevents undue stress on the underside of the drive shaft bellows.

.
 
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wow some great info there. Joe, i think im going to have to pass on that 170 for now. Thanks for looking out tho. Rick, you definately have alot of knowledge on my situation. I wish you were closer than across the country. I can see that i am in way over my head. Perhaps i should alter my plan a little. My problem is where to start? I think i need to identify an engine that would fit, then identify all of the components i would need to adapt it to my out drive. then start the hunt. I would be able to amass all of these while still using my 170. Then when i got them all together, i could sell the 170 while its in the boat and they could see it run. Would there be a skematic or a list somewhere with part numbers or descriptions or anything like that available? I really appreciate you guys and your input. thanks again -kevin
 
Kevin, with exception to p/n's, I did list the parts that you'll need.
A V-8 will basically go back in just as your 170 comes out.

As for the Y pipe, there is a single relief pipe on e-Bay, but it's for the V-6. It could be made to work, I suppose!
It will give you an idea of the difference between the double and single exhaust reliefs.

I'll keep an eye out for the AQ 200B pipe.

This double relief Y pipe below is also on e-Bay, but someone has cut off the top bends.
If you look, you can see the two relief ports.
Your transom shield will have only one of these ports.
This is why the AQ 200B pipe must be used..... or, you change the transom shield to an AQ 260 or an AQ 225 C or E double relief style!
Ca-Ching.... $$$$$$$$$
 

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thanks so much for looking out for me ricardo. ok so i think im starting to figure this out. I need the flywheel cover because it will allow me to bolt just about any v8 up to my outdrive. I need that double exhaust as my exhaust only comes out on one side of the motor and on a v8/6 the exhaust would come out on both sides. After that, all that is really left to hunt up is the lower end ratio. After i get these things, i could drop any v8 in? marine or otherwise? Im a little lost on the seawater pump. Is that something that is added to a standard engine to allow for the use of the sea water as cooling or does it just come with any marine engine? I feel like im getting close here. thanks again for all your help! -kevin
 
Not exactly... let me comment.
kevinmi said:
I need the flywheel cover because it will allow me to bolt just about any v8 up to my outdrive.
Only the GM V-8 rear engine flange mates to this flywheel cover.
If you go Ford, then the flywheel cover changes to Ford.

I need that double exhaust as my exhaust only comes out on one side of the motor and on a v8/6 the exhaust would come out on both sides.
You can go either route.
Use your single relief transom shield, and find a 3" V-8 single relief Y-pipe.... (I.E., the AQ 200B or 225B that I mentioned earlier)
Or... purchase a very expensive double relief transom shield, and the AQ 260 Y-pipe.

After that, all that is really left to hunt up is the lower end ratio.
Correct. This will be the 1.61:1 in the s/p....., or a 1.95:1 in the Duo Prop lower.

After i get these things, i could drop any v8 in? marine or otherwise?
No! An automotive built SBC would not be a good choice, IMO.

Im a little lost on the seawater pump. Is that something that is added to a standard engine to allow for the use of the sea water as cooling or does it just come with any marine engine?
The GM SBC pump is the Engine Circulating Pump..... you'll also need a sea water pump.
IMO, you can't beat the Johnson Crankshaft style pump..... and it's what would have been OEM had your boat come with a V-8 (actually, it would have been Jabsco.... but one replaces the other).
The flange adapts to and bolts to the harmonic balancer and belt shiv.
JOH10242321.jpg


-kevin
Click to expand...
It's actually a very doable and easy conversion.

.
 
I have a friend with this same boat and the 5.7L w/ single prop drive.
With the use that you intend, I'd go with a SBC 5.7L engine.
Or... go with the 4.3L and the Duo Prop lower unit.

The boat will perform well with more power.

attachment.php

This photo is why I mentioned storing your drive fullly down and aimed fwd, as to extend the life of your drive shaft bellows.

.
 
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good call on the drive..i just had it up at the launch. i trailer it 45 minutes just to get to the water. the trailer is a 1973 and it has its own set of problems lulz. I will remember to put it down when i get home now that you mention it. thanks again for all your help rick. Im expecting the pertronix kit in on saturday and am very curious to see if that helps things as the cam in my distributor is slightly worn on 2 corners. I can always get things sounding good in the driveway but on the water and under load is another thing all together. hard to believe i had it goin 30mph last summer..i can barely go 14 now.
 
kevinmi said:
Im expecting the pertronix kit in on saturday and am very curious to see if that helps things as the cam in my distributor is slightly worn on 2 corners.
Click to expand...
Be sure to not only set BASE ignition advance, but to also see what your advance is doing at the higher RPM.... up near 3k rpm or so.
See your OEM specs for TA (total advance) and make sure that the distributor is giving the correct spark lead.
If not...... engine performance will suffer greatly.

Nice pictures and what a nice family.
A man who's family is willing to go fishing with him, is a lucky man!
He's even more lucky if they'll help cook the fish and clean the boat up afterwards!

He's even more lucky yet if they don't mind the budget that's required! Ouch! :D

.
 
i got the pertronix kit in but i couldnt get it to turnover... it just ticks. i must have knocked a wire loose on the starter. no worries. its bad weather this weekend anyhow. I will get after it tomorrow. I will keep you posted. thanks again for all the info.
 
Your best bet is to try and find a rotten donor boat with the driveline intact. You most likely need to rebuild the engine, but all the parts should be there. Much cheaper option IMO.
 
just an update. Well i got the starter issue worked out. it was just a loose wire. I couldnt get the pertronix to work. We figured it out pretty quickly tho. We had to really push that magnetic thing down onto the cam lobes. Once we did that, holy crap did it spark. with the 2 lobes wore down, it had been running on 4 cyls for a while. I wasnt able to get it out onto the water and test it but it sure sounded strong w/ the muffs on. Saturday will be the day of reckoning. If it runs good, im probably gonna try and put the engine swap off for a bit. I will still be keeping an eye out for stuff. Im thinking like what rob said. If i can buy one that is already converted, most of the parts i want wont be bad. Then its just an issue of fixing the motor. after what ive been thru with this 35 year old motor, im more than up for that challenge. I dont want to be too optimistic, but something tells me this conversion to electronic ignition, is going to be a huge boost. After saturday i will know for sure. Thanks so much again guys. your help has been great. -kevin (soon to be back on lake huron catching some salmon)
 
Hi, my 2 cents worth. When my old OMC gave up, I ripped the whole lot out, had the transom hole filled in and added a pod / duckboard to the transom. From the pics, your boat would be easy to add a pod to. Then I added a 200hp Yamaha outboard. Best thing I ever did. Better ride and handling. On the plane quicker and uses less fuel. I have now had 12 months of trouble free boating.
 
thanks for the idea dave. i think i saw a boat at the launch one time that had that done. I think after this last little episode, im just gonna keep it as is for now but will keep an eye out for conversion pieces. Im gonna start a new thread as im now having problems w/ the rpms and getting on plane but the engine seems to be running, at least at low speeds, well. thanks again for all of you guys imput.
 
Kevin, I'd stay with the Volvo Penta, save yourself the frustrations of an outboard.
But not that 1973 stuff. That is very likely a 200 or 250 drive and components. Too old!
You can't beat the V/P....

Kevin, contrary to what some think, there is a correct dwell setting with the Pertronix kit, and this is controlled via the gap between the magnetic unit, and the sensor unit. Any excessive distributor shaft play, can/may throw the dwell out of whack.

Also..... you may have noticed a shim in the kit.
This shim is to help adjust and align the sensor and magnetic unit vertically.
There is a range that these must remain within, in order to work at max potential.
The shim may or may not be required.


And at the risk of being redundant.... check your ignition TA.
Not BASE or Initial.... we're talking TA (total advance)
If this is not within OEM specs, performance will suffer.
The new Pertronix will do little for you unless TA is correct. :D

.
 
Like said earlier, the only real changes he'd need to make, would be the lower unit ratio, the AQ 200B Y-pipe, and a V engine flywheel cover... plus the misc small parts.
But yes.... a donor boat would be a great way to go.
 
ok im gonna start a new thread with the trouble im having now. thanks so much for the help you guys! you really know your stuff and now i have a list of parts to look for. I will hopefully hear from you regarding my latest problems. Im not going to give up. This boat will work right! thanks again -kevin
 
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