VP 280 Engine Alignment

[adamkat22]

hey all, i have a volvo penta 280 and gm 350. i stripped everything down to rebuild a rotten transom, and then ended up doing the stringers in the engine compartment as well. i did my best to build the stringers that the engine was mounted to at their original height...but i'm pretty confident it's not perfect (big learning curve yikes). prior owner had the engine mounts connected to some angle iron and then bolted through the side of the stringer, so it's more the height off the hull that i'm worried about. anyways, i'm trying to figure out the best way to put this all back together.

should i re-install with the bell housing attached to the motor, or is there an advantage to connecting just the bell housing to the transom shield first, to be able to site things, and then slide the engine in after?

know of any good threads/videos that go over alignment of the engine? i can find them for other engines/outdrives, but not this combo.

thanks for any thoughts

 

[kenny nunez]

Just bolt the whole thing together Into the transom plate. Then with either the diameter of a pencil eraser or similar item use that as a gauge around the outer perimeter of the mounting collar to the transom plate. That will properly set the alignment.

 

[Scott Danforth]

There are 3 bosses at 3,9, and 12 o'clock positions.

Use feeler gauges and make sure all 3 are within 1.5 mm or 0.060"

Simplest drive to align

 

[adamkat22]

sorry a few clarifying questions:
What part of the engine are bosses located on?
Also, since the engine mounts are bolted onto angle iron that can slide on the stringer, would it be best to mount the flywheel cover to the transom plate first, so I can slide the engine mostly into place while still on the crane, and visually see how close I am? Or is it best to drop the whole thing in as one piece, in which case it seems like the bolts on the clamp ring might have to pull the whole engine into place?

Thanks so much you all! Definitely bit off more than I thought with this project, but this forum is helping me get through it…

 

[Scott Danforth]

The bosses are on the PDS, you are measuring PDS to transom shield

You want all 3 to be within 1.5mm of each other. Really is you will most likely be with 0.8mm (0.030") of each other

You have the transom shield bolted in.

Then you have the motor and PDS bolted together and you drop the motor and PDS in together

Trying to leave the PDS in the boat is 100 times harder than doing it correctly

 

[adamkat22]

Ok great. And final question (haha probably not my final one..but for today at least) . Is there a way of measuring off the transom shield before I drop the engine in to see if it seems like my stringers are close enough to the correct height? I’m pretty worried I goofed that part and don’t have great site lines to double check

 

[Scott Danforth]

No. You are at a trial fit and measure point

That is why the front mounts are adjustable

 

[adamkat22]

Am I being naive in thinking that if I get the stringers within 1/2” of their original height I should be able to nail it on the first shot? With the mounts set in the middle I probably have a good 3/4” to move in either direction…

 

[Scott Danforth]

If you took good measurements prior, you should be able to get the stringers and motor mounts closer than 1/2"

You can always add shims under the mounts if you are too low, however if you are too high, it can bite you

 

[kenny nunez]

If you are in doubt then try to hang the front of the engine with the engine hoist. Or a small jack under the engine. Then loosen the mounts and raise and lower the engine easily to set the alignment. This saves a lot of time instead of turning the nuts to set the alignment.