convert 3.0 chevy volvo sx to 3800's
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Extremely expensive, the two biggest problems are:
1. The bellhousing on the 3800 is different than any other marine bellhousing out there now or ever and never used on a US marinized engine (with the possible exception of the Northstar V8 that was used in some ski boats). The one on my marine engine was made in either Australia or New Zealand, so these would be high dollar items and you need two.
2. The water cooled marine manifolds are also unique to this engine and, again made in either of the two places above.
I'd guess $3000 for two sets of marine manifolds and bellhousings and that's just for starters... If you want more power a 4.3L Chevy will fit the bellhousing you now have and is readily available used already fit for marine duty.
1. The bellhousing on the 3800 is different than any other marine bellhousing out there now or ever and never used on a US marinized engine (with the possible exception of the Northstar V8 that was used in some ski boats). The one on my marine engine was made in either Australia or New Zealand, so these would be high dollar items and you need two.
2. The water cooled marine manifolds are also unique to this engine and, again made in either of the two places above.
I'd guess $3000 for two sets of marine manifolds and bellhousings and that's just for starters... If you want more power a 4.3L Chevy will fit the bellhousing you now have and is readily available used already fit for marine duty.
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I have a 4.3 in my blazer and think it would make a better boat anchor than a boat engine. It's a friggin' turd.
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1,151 Posts
We got the 220hp fuel injected version of the Volvo 4.3L in our 19 foot Four Winns and she flies, would be so much simpler to just stick with marine engines.
3.0L Conversion
A couple considerations:
1) Engine width - The 3.0L is narrower than the V6, so twins can be mounted closer together. Maybe to close for V6's. Consider 30 inches between crankshaft centerlines as the minimum.
2) Drive Ratio - The 3.0L is usually mated to a 2.0:1 ratio drive (assuming single prop. I don't know of any 3.0L duo-prop applications). The 4.3L is used with a 1.65:1 or 1.81:1. Although you may get lucky and be able to find a set of props that will hold RPM's where they need to be, check the cost of regearing 2 drives, just in case.
3) Fuel consumption - The V6's will drain the tanks faster, so you will have reduced range and more frequent fuel stops with the current tanks.
4) The 3.0L's are cheap and plentiful. If the performance is adequate, save your money. MerCruiser sells a CPO (cert. pre-owned) 3.0 that lists for under $3300 U.S. Same base GM engine as the Volvos. You should be able to swap the bell hsg & coupler, adapt the exhaust, and go.
A couple considerations:
1) Engine width - The 3.0L is narrower than the V6, so twins can be mounted closer together. Maybe to close for V6's. Consider 30 inches between crankshaft centerlines as the minimum.
2) Drive Ratio - The 3.0L is usually mated to a 2.0:1 ratio drive (assuming single prop. I don't know of any 3.0L duo-prop applications). The 4.3L is used with a 1.65:1 or 1.81:1. Although you may get lucky and be able to find a set of props that will hold RPM's where they need to be, check the cost of regearing 2 drives, just in case.
3) Fuel consumption - The V6's will drain the tanks faster, so you will have reduced range and more frequent fuel stops with the current tanks.
4) The 3.0L's are cheap and plentiful. If the performance is adequate, save your money. MerCruiser sells a CPO (cert. pre-owned) 3.0 that lists for under $3300 U.S. Same base GM engine as the Volvos. You should be able to swap the bell hsg & coupler, adapt the exhaust, and go.
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