Swap engine - but what about camshaft?

[Danmarine]

Hello everyone.

Well, it ends with a total replacement of the engine.

The current engine is a Volvo Penta 5.0 GL-B V8 GM, 2 barrel carburetor, 1 electric fuel pump.

Replacement engine, is a Chevrolet Performance 350 / 5.7 V8 Vortec.

The problem is that the camshaft must probably be replaced, with regard to the back pressure in the exhaust.
But the question then is whether the cam from 5.0 (the current engine) will fit in the new engine? I think they do, but am a little in doubt.
Info about the new engine:
Power-cyl. heads with 1.94 in. intake valves and 1.50 in. Exhausts, and 64cc combustion chambers that yield a 9.4: 1 compression ratio. This combination is paired up with a roller cam that has 0.414 in. of intake lift and 0.428 in. for the exhausts. Duration at 0.050 in. of lift is 191 degrees for the intakes and 196 for the exhausts, with 111 degrees of lobe separation.

So what do you think about it, will it be an option or should we grab another bump?

Of course, frost plugs etc. must also be replaced, but it is now mostly the cam we are struggling with.

Thanks

 

[Bondo]

Ayuh,... Is this a reman motor, rebuilt motor, or new from Chevy motor,..??

The cam in it will run just fine in a boat,.....
Don't reuse the old cam,....
If you want a new cam, find a idle to 5000 rpm, RV cam for it,....

 

[Danmarine]

Hi Bondo, thanks for the feedback.

It's a brand new Chevy engine.
I also think you can easily use the current one - but I just doubt if there can be any challenges with the overlap on the cam according to the exhaust valve and the intake valve and the timing thereof?

But if it is thought that it can easily run with the cam that is mounted (I think it can also), then it will be the easiest!

No, you are right. Reusing the old camshaft is of course something bad, now that I really just think it through properly ....; P

Thanks

 

[itsathepete]

The cam from the 350 will work fine as Bondo said. No problems with valve timing with that cam.

 

[Danmarine]

Hi Itsathepete

Thanks for the feedback. It's super nice, so that part was just saved away!
Thanks

 

[Bt Doctur]

I believe it starts having issues above 210 or so degrees duration.

 

[Danmarine]

Hi Bt Doctur
You may be right. It fits very well with some of the other camshafts and the difference between them.

But it's always nice when most things fit in and you do not have to modify or rebuild anything; =)

Thanks to all of u´

 

[Danmarine]

Hello everyone.

Now I had the engines swapped around, it required some new parts and other little things.

But it starts fine and runs well - as well as it can now with a basic adjustment of timing.

But I've got a problem - it can not draw cooling water up from the drive and feed it through the exhaust. There is a nice review and I can easily back-flush it all. The impeller is fine and the housing is fine ... It worked on the old engine and now it does not work?
It's on land and I use flush sleeves. Have you experienced anything similar? Is a little worried about whether it is due to a different cooling system on this engine, GM V8 5.7 GL unlike the other was a GM V8 5.0 GL. I do not think there is any difference, but why it suddenly will not cool properly I do not know ..... yet.

One possibility could be a lack of revs, but I can not get the timing or revs adjusted at the moment.
1) I have fitted a new carburetor 500 CFM 2bbl marine and the engine suffers with the supply of fuel, it lags and splashes and goes out after some time and the exhaust is hot.

2) I can not adjust the timing as I do not have enough time to get it up to speed and keep it there without the engine getting too hot or going out. The timing is set on TDC and I would like to have it adjusted to 8-10 degrees before TDC.

So it's all a bit tiring and practice and in the first place I must have clarified if there is something I have overlooked in the cooling. It is salt water cooled throughout. All pipes, hoses, etc. are in good condition, tensioned and tight. I also checked the O-ring down by the drive and it is also ok.
If I connect the water hose directly to the SW pump, water will come up to the exhaust.

Do you have any good inputs or things I might just need to take and get checked otherwise?

Once again thank you