Volvo Penta 280 verses 290 outdrive question.

[Alaskan Mariner]

I have a 280 tranny and a 290 lower. Can these two be compatible with each other? I'm running a 350 vortex engine w/ approximately 340 hp. I believe the answer would be probably not. What's the verdict?

 

[Scott Danforth]

same lower section, different mid sections and tilt/trim arrangements

the 290 sat behind big blocks and diesels. it wont know your 350 is there

 

[Scott Danforth]

so how are you getting 340hp out of a 350 with wet exhaust?

if you are trying to run more than 270 degree duration on the cam, you will suffer reversion. the most I could ever get with a marine motor and naturally aspirated was about 330hp. to get more, have to jump to a 383 or larger stroker

 

[Alaskan Mariner]

so how are you getting 340hp out of a 350 with wet exhaust?

if you are trying to run more than 270 degree duration on the cam, you will suffer reversion. the most I could ever get with a marine motor and naturally aspirated was about 330hp. to get more, have to jump to a 383 or larger stroker

I have a 350 vortex engine from a 1 ton chev. Van. Mechanic friend explained being such, delivers more HP than the Marine application motor, usually not more than about 270-280 hp. I'm not a mechanic, still learning. Advice is always appreciated. Thanks.

 

[Alaskan Mariner]

same lower section, different mid sections and tilt/trim arrangements

the 290 sat behind big blocks and diesels. it wont know your 350 is there

Thanks, I understand the lower 290 is a stronger/ heavier unit. Is the 280 single prop tranny , as a lighter gage tranny ok to run on top of the 290 dual prop lower?

 

[Scott Danforth]

The transmission is the same for the 270, 280, and 290. The 280 and 290 are available with single and dual prop lowers.

The main difference of the 280 vs 290 is the tilt/trim and the mid section. Not the trans, and not the lower

 

[Scott Danforth]

I have a 350 vortex engine from a 1 ton chev. Van. Mechanic friend explained being such, delivers more HP than the Marine application motor, usually not more than about 270-280 hp. I'm not a mechanic, still learning. Advice is always appreciated. Thanks.

Your friend doesnt know what he is talking about

Did you swap head gaskets to marine? Core plugs to brass or stainless, and switch to a marine circulation pump?

350 with vortec heads and stock truck/van cam is about 280hp. (260hp at prop) cam is almost identical to marine cam. Not sure where you get 330hp from

 

[Alaskan Mariner]

Your friend doesnt know what he is talking about

Did you swap head gaskets to marine? Core plugs to brass or stainless, and switch to a marine circulation pump?

350 with vortec heads and stock truck/van cam is about 280hp. (260hp at prop) cam is almost identical to marine cam. Not sure where you get 330hp from

Yes to all the questions. Did a total switch to marine. This Hp information is appreciated, not here to argue. My question is, can a 280 tranny work on top a 290 dual prop lower. Yes or no. Thanks.

 

[Scott Danforth]

you didnt read my answers in post #6.

 

[72fj40]

Yes to all the questions. Did a total switch to marine. This Hp information is appreciated, not here to argue. My question is, can a 280 tranny work on top a 290 dual prop lower. Yes or no. Thanks.

Yes, it needs to be the correct gear ratio, and you should pull the bearing race and shim that's in the bottom of the 290's intermediate housing and install it in the 280's intermediate housing, and confirm it has the correct preload per the fsm. You'll need to run heavier gear oil per fsm.

 

[Alaskan Mariner]

Yes, it needs to be the correct gear ratio, and you should pull the bearing race and shim that's in the bottom of the 290's intermediate housing and install it in the 280's intermediate housing, and confirm it has the correct preload per the fsm. You'll need to run heavier gear oil per fsm. View attachment 346561

Very good. I already changed the bearing race & shims to match. I am using Valvoline 75/90 in my out drive. Is that ok?

 

[Alaskan Mariner]

you didnt read my answers in post #6.

I did read it but I just wasn't 100% clear, due to alot of prior misinformation. Thank you for the clarification. I will correct a couple of friends as well.

 

[Alaskan Mariner]

Very good. I already changed the bearing race & shims to match. I am using Valvoline 75/90 in my out drive. Is that ok?

What is the gear ratio compared to? If there is only a gear ratio in the lower but not the upper, what makes it the right one/ compatible ? Is it determined by the engine size or?

 

[72fj40]

So, I found a free FSM for volvo 280/290 sp & dp drives and downloaded it to my computer, phone, and I also printed it out. I also found several parts diagrams from the transom plate to the lower unit, so I could see how things go together and to id the parts needed and to get part #'s. The manual says sae 90 gl5, 80w90 gl5, or 75-90 synthetic gl5. Most Volvo techs say synthetic for dp's. The upper gear box shifts direction, the lower unit has the gear ratio. They are not compared to anything except x.xx:1. Ratios differ for different engines from 6cldrs, V8's, sbc's, bbc's & diesels. Once you get the right dp lower ratio, then you'll have to figure out what prop set to get.

 

[Scott Danforth]

What is the gear ratio compared to? If there is only a gear ratio in the lower but not the upper, what makes it the right one/ compatible ? Is it determined by the engine size or?

for DP drives - the ratio is as follows
2.15:1 are for V6's
1.95:1 are for small block V8's (you can also run a BBC on these)
1.78:1 are for diesels and BBC's

it is more efficient to run the correct gear ratio than to try to make up with prop changes

as stated, the upper trans is the exact same part (assuming same vintage of drive) for the 270/280/290 there are early transmissions that used shims and later transmissions that use crush sleeves.

input shafts changed from 10 splines to 26 about the time that GM changed the transmissions from 10 splines to 26 (early 80's)

 

[Alaskan Mariner]

for DP drives - the ratio is as follows
2.15:1 are for V6's
1.95:1 are for small block V8's (you can also run a BBC on these)
1.78:1 are for diesels and BBC's

it is more efficient to run the correct gear ratio than to try to make up with prop changes

as stated, the upper trans is the exact same part (assuming same vintage of drive) for the 270/280/290 there are early transmissions that used shims and later transmissions that use crush sleeves.

input shafts changed from 10 splines to 26 about the time that GM changed the transmissions from 10 splines to 26 (early 80's)

Most excellent information, this I can understand. Thank you.

 

[Alaskan Mariner]

So, I found a free FSM for volvo 280/290 sp & dp drives and downloaded it to my computer, phone, and I also printed it out. I also found several parts diagrams from the transom plate to the lower unit, so I could see how things go together and to id the parts needed and to get part #'s. The manual says sae 90 gl5, 80w90 gl5, or 75-90 synthetic gl5. Most Volvo techs say synthetic for dp's. The upper gear box shifts direction, the lower unit has the gear ratio. They are not compared to anything except x.xx:1. Ratios differ for different engines from 6cldrs, V8's, sbc's, bbc's & diesels. Once you get the right dp lower ratio, then you'll have to figure out what prop set to get.

Very informative, wasn't expecting so much of your research. Thank you. This has been very helpful. I now have it all put together & running great. Seward, Ak. bound Sunday for a Halibut test drive. I feel confident ,from all the help with this out drive I have received, it will get me out & back. Fish on. Thanks for everyone's help there.