Kola16
Petty Officer 1st Class
- Joined
- Jun 23, 2019
- Messages
- 206
I apologize for the long story, but I will try to keep it short yet detailed. Ask questions if I need to elaborate.
I assembled a custom 383 stroker engine to replace my 350 block. More details in my signature, but it has a Holley Sniper EFI and Pertronix electronic ignition set to 12* at idle. The drive is an old Mercruiser 228. I don't have the money to upgrade to a Bravo drive, but I do have a drive shower and a raw water pickup that keeps the engine running at 170*F. I drive it nicely, not like a wild child due to the drive.
I put the engine in originally with a used OEM Bravo coupler and got this same screeching noise. I put alignment lines with a sharpie on this used coupler and sure enough, the lines were off. The coupler was spinning. When I pulled the engine out, I decided to replace the transom and stringers since there were some bad spots and I figured that was the problem. I rebuilt the transom to 2-1/4" and measured all the parallelism, thickness, flatness, and so on. The stringers were rebuilt solid too. Both engine mount stringers and stringers to the transom. All fiberglassing was rebuilt much better than what was done at the factory. Picture just for your curiosity after fiberglassing and reinstalling transom plate.
So with the new transom and stringers I put everything back in which includes the newer power steering ram, new OEM front engine mounts, new OEM Bravo engine coupler this time, OEM Bravo flywheel housing assembly, and OEM Bravo inner transom plate. The U-joints and gimbal bearing are also new and move smoothly.
To get the alignment correct, it took the stainless steel washers, spring washers, and fiber washers under the rubber rear engine mount bushings to get the alignment bar to slide in and out and spin easily with two fingers. That doesn't seem normal does it? I thought you use either the spring washers, or the stainless washers, but not both? But for me, that was the only way to get it aligned correctly. Anyway, took the boat to the lake joyously thinking I was done, only to get this noise again with the video linked above. My heart sank. It makes the noise when accelerating, but the noise stops when I pull back on the throttle a little bit. I can't really get it to make the noise on the hose, or in neutral on the water even when throttling up. I know it is not a belt or pulley because I took the circulating engine coolant water pump belt that also goes to the alternator, and power steering pump belt off for a second and still got this noise. There is still the crank mounted raw water pump that I suppose could make this noise, but the noise sounds like it was coming from the back of the engine. I did have alignment marks on the new engine coupler and looked at them, but to my surprise, they appear to be on. No spun coupler? I guess it could have done full revolution(s) and landed right back on the mark, but that isn't super likely. See the green mark below. It is hard to get a picture of so I apologize for the quality. The grease seemed to wash off all the other marks except 1 maybe which appeared to be on too.
So I am at a loss and I would greatly appreciate some help. I have spent all spring and summer working on this boat, and I am at a loss. My plan is to take the outdrive off to see if the alignment is still on, but would like some insight before I put more work into this since I am pretty burnt out at this point. Is my rear mounting setup wrong? Did I just somehow get a bad new coupler and it is the inner part that is spinning (between splines and rubber? I was told by one mechanic that it could be timing related!? Your guys' knowledge would be greatly appreciated. Thank you for your time.
I assembled a custom 383 stroker engine to replace my 350 block. More details in my signature, but it has a Holley Sniper EFI and Pertronix electronic ignition set to 12* at idle. The drive is an old Mercruiser 228. I don't have the money to upgrade to a Bravo drive, but I do have a drive shower and a raw water pickup that keeps the engine running at 170*F. I drive it nicely, not like a wild child due to the drive.
I put the engine in originally with a used OEM Bravo coupler and got this same screeching noise. I put alignment lines with a sharpie on this used coupler and sure enough, the lines were off. The coupler was spinning. When I pulled the engine out, I decided to replace the transom and stringers since there were some bad spots and I figured that was the problem. I rebuilt the transom to 2-1/4" and measured all the parallelism, thickness, flatness, and so on. The stringers were rebuilt solid too. Both engine mount stringers and stringers to the transom. All fiberglassing was rebuilt much better than what was done at the factory. Picture just for your curiosity after fiberglassing and reinstalling transom plate.
So with the new transom and stringers I put everything back in which includes the newer power steering ram, new OEM front engine mounts, new OEM Bravo engine coupler this time, OEM Bravo flywheel housing assembly, and OEM Bravo inner transom plate. The U-joints and gimbal bearing are also new and move smoothly.
To get the alignment correct, it took the stainless steel washers, spring washers, and fiber washers under the rubber rear engine mount bushings to get the alignment bar to slide in and out and spin easily with two fingers. That doesn't seem normal does it? I thought you use either the spring washers, or the stainless washers, but not both? But for me, that was the only way to get it aligned correctly. Anyway, took the boat to the lake joyously thinking I was done, only to get this noise again with the video linked above. My heart sank. It makes the noise when accelerating, but the noise stops when I pull back on the throttle a little bit. I can't really get it to make the noise on the hose, or in neutral on the water even when throttling up. I know it is not a belt or pulley because I took the circulating engine coolant water pump belt that also goes to the alternator, and power steering pump belt off for a second and still got this noise. There is still the crank mounted raw water pump that I suppose could make this noise, but the noise sounds like it was coming from the back of the engine. I did have alignment marks on the new engine coupler and looked at them, but to my surprise, they appear to be on. No spun coupler? I guess it could have done full revolution(s) and landed right back on the mark, but that isn't super likely. See the green mark below. It is hard to get a picture of so I apologize for the quality. The grease seemed to wash off all the other marks except 1 maybe which appeared to be on too.
So I am at a loss and I would greatly appreciate some help. I have spent all spring and summer working on this boat, and I am at a loss. My plan is to take the outdrive off to see if the alignment is still on, but would like some insight before I put more work into this since I am pretty burnt out at this point. Is my rear mounting setup wrong? Did I just somehow get a bad new coupler and it is the inner part that is spinning (between splines and rubber? I was told by one mechanic that it could be timing related!? Your guys' knowledge would be greatly appreciated. Thank you for your time.
