Alignment still an issue
 

In getting my engine and gimbal bearing properly aligned it's dead on. The problem is I needed to locate the center line of the crank roughly 1-1/2" to left of the hull center line. I can determine this just from eyeballing it, but I also took measurements. I realize my hull may not be perfect, but this seems extreme. What could be a probable cause for this? My exhaust is thru hull, and I'm going from manifolds to CMI elbow top headers. It's a cinch the tail pipes are not going to line up with the original holes. This is what has me concerned with the engine seemingly cocked to one side. The plywood on the transom was replaced along with the engine bed. I still need to determine where to drill the front mount holes. If I move the front of the engine to what looks to be centered, the coupler will not line up under any condition. I,m stumped and this problem is holding up the whole project. I would greatly appreciate any opinions!

What kind of boat.... Bayliner??? Sorry I had to ask.

The transom assembly can’t be square n relation to the stringers. If this is true the boat was not constructed properly or the transom is soft and the inner plate is cocked. You can check easily with a framing square or mark each stringer at 2’ from the transom and the measure diagonally from each transom plate mounting ear to the mark on the opposite stringer. The measurements should be equal if the transom plate is square.

The boat is an '88 Nordic Crestliner Rampage 26'. Not high end, but probably comparable to a Wellcraft of the the time. I can't say what position the original block was in. I never really took notice. I doubt it's a case of soft wood on the transom. I replaced it last summer. I also tightened the transom plate bolts as evenly as possible. I would think a diagonal measurement should tell me something. It's hard to comprehend the transom would be off square. Maybe I should mention the transom is pitched back maybe 12 degrees if that has any relevance? Common sense tells me the geometry of the transom plate dictates the location of the block. Would it not also be in relation to the transom assembly? Would it be feasible to shim one side of the transom plate? If I can't figure this out, I may just have to go with what appears to be a cockeyed engine! Or is it???

First, there is NOTHING straight, square or true on a fiberglass boat..lol

When I raised my X we located the X on the back of the transom, centered the jig to that, drilled and cut. Then mounted the transom assbly and lowered the motor in and snugged the ream mounts in the bellhousing, then used the hoist to align it so the alignment bar when in and out easily, left the bar in and drilled the front mount holes and tightend everything down.

Once the transom assembly and innerplate are on, the alignment bar is going to dictate where the front mount goes. It may not look or seem right, but the bar is the truth

I agree. It can be very hard to get a precise measurement or reference where a glass hull is concerned. I'm trying to figure out if I'm seeing an illusion or is it really that far off? Measurements tell me it is, but can I trust them? My eyes looking at the center of the keel (if that's what it's still called?) tell me I'm right!

Have you tried to loosen one or both of the rear bolts? If you really are that far from centered they should be in a real bind. Did you square the gimble bearing up before you started? I get everything lined up mathematically before I drop the engine in and the adjustments are always very minor after that. The engine has to be perpendicular to the inner plate side to side and up and down. I use straight edges and a framing square.

First I had an issue with a new bell housing because of the new style bushings. I had to swap out the double spiral for a single lock washer. That worked out well. I'm measuring from the edge of the inboard decking (floor boards) to the shaft of the circulating pump. When the block is centered, the rear mount bolts tend to bind. This tells me the block is not square to the transom plate. I also used a drywall T square from the transom along the length of the block as a reference. It can be tricky with a pitched transom. I have a chain hoist at the front and rear of the block, so making adjustments isn't too difficult. I had to nurse the gimbal bearing a bit, but the alignment bar seems to favor the engine off to one side. I'm beginning to think it is what it is, and there is nothing I can do about it. Unless of course someone has a solution. I appreciate the feedback!

Not sure what is going on with your boat but if you set your mounts up so they are exactly square to the inner plate you will be within ****hairs of the goal. Here are some really bad pictures of the important measurements.
https://cimg2.ibsrv.net/gimg/www.off...ea874e29b.jpeg
https://cimg4.ibsrv.net/gimg/www.off...2a12b47e8.jpeg
A is from the starboard mount stud to the port transom plate bolt and B is the opposite. C and D are between straight edges laid across front mounts and rear mounts.

Sorry to hear about your issues. That sucks but certainly not the first time for something like this. Like phragle mentioned nothing truly square in a wooden or glass etc boat. I might not be getting a 100% but can you shim anywhere to find a happy medium. My biggest concern would be the potential stress on the side load of seals / bearings. I might have missed it but if you drop your transom mount bolts in place from what I understand is your engine is not parallel to your stringers resulting in not mating with the front mounts. If you can get the drive on without force is it possible to do as motioned above with shimming or offsetting forward mounts. Kinda funny I've used a drywall square myself in the bilge for various reasons over the years but typically leaves me scratching my head for reasons like phragle said.