Repowering Volvo AQ260?? short/long block?

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Rainbow Bridge

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Hi,

My 79 Bayliner AQ260A (350CI Chevy) Volvo has a leak waaay down in the bottom of the exhaust yoke, (think it's a crack), so i have to pull the engine. It's got 820 hrs, many in salt water, but I've done the heads twice and installed a new oil pan, elelbrock intake, exhaust manifolds, starter, alternator and fuel pump. Also, it checks out at 120PSI compression in all cylinders...so here's the question..do i replace the block? and if so...

1) stay with the quadrajet or go EFI?

2) swap the heads and go short block?

3) Keep the old Prestolite distributor? (which i put electronic ignition in)

Thanks for your input!!

Russ
 
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captmello

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Re: Repowering Volvo AQ260?? short/long block?

I have the same engine as you. The only thing I would consider changing would be to vortec heads, meaning Long block replacement. Depending on how old the exhaust manifolds are, if they've been in the salt, might be a good thing to do. You can do the ignition upgrade anytime, I use the old points and condenser setup. Seems to work just fine.
 
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Rainbow Bridge

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Re: Repowering Volvo AQ260?? short/long block?

Thanks for your reply....what is the difference, or benefit of vortec heads?

Thanks,
Russ
 
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captmello

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Re: Repowering Volvo AQ260?? short/long block?

Rainbow Bridge said:
Thanks for your reply....what is the difference, or benefit of vortec heads?

Thanks,
Russ
Click to expand...

about 30 HP.

I forgot to mention you'd need a new intake manifold. I would also consider a new carb. Whether its a Qjet or some other.
 
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Rainbow Bridge

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Re: Repowering Volvo AQ260?? short/long block?

Wow!! How interesting! When I the original heads, the guy at the shop sold me some "heavy duty" cast iron heads off a 65 impala...saying they'd be better in salt water. he put in hardened valve seats....but an exhaust valve did burn. I ripped em off again...and he fixed that...and they've been on for 5 years now.

so, you're saying instead of 260 horse, it would be 290? would that require re-pitching the props?
 
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captmello

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Re: Repowering Volvo AQ260?? short/long block?

Rainbow Bridge said:
Wow!! How interesting! When I the original heads, the guy at the shop sold me some "heavy duty" cast iron heads off a 65 impala...saying they'd be better in salt water. he put in hardened valve seats....but an exhaust valve did burn. I ripped em off again...and he fixed that...and they've been on for 5 years now.

so, you're saying instead of 260 horse, it would be 290? would that require re-pitching the props?
Click to expand...

I can't say what you'd have to do with the Prop. If you've got 120 compression on your current engine, I would expect a new one to be 150+ PSI. Between the increased compression and Vortec heads, you'd be looking at quite a power increase.

I guess if I was to go to all that work, I'd replace the whole long block, along with a new intake (if you switched to Vortec heads) and carb and new exhaust manifolds. I've heard bad stories about people reusing old exhaust manifolds only to have them ruin their new engine, or installing an old carb that isn't any good and damaging the new motor. You can get a new carb for $300.
 
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piratedude

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Re: Repowering Volvo AQ260?? short/long block?

What ever u do dont buy a engine from michigan motorz....ripoff. No aftermarket service and shoddy work. Just have a good shop do a rebuild engine 4 w/ vortec heads. My 26' boat now goes 40 mph w/ a 5.7 in it! Used to top out at 33.
 
zbnutcase

zbnutcase

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Re: Repowering Volvo AQ260?? short/long block?

And chances are your exhaust yoke is corroded through from salt water, not cracked. And I would use the 1409 Edelbrock marine carb on your new engine.
 
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Rainbow Bridge

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Re: Repowering Volvo AQ260?? short/long block?

Thanks for that info....

I'm afraid of rebuilding my block...because of salt water...

and....can that exhaust yoke be repaired? or just replaced.??

That's what started me on this whole journey...I would have kept the engine in till 1200 hours....

but as i see it...there's no way to remove the yoke with the engine in, right?

Thanks,
Russ
 
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