Bob's vrs Allison foil

[whipper]

Goop hears the thread on the gearcase redo if your interested. Its just paint. I had to redo the whole thing from scratch. It wasnt to bad. The link hear has the whole prosses with pics of course.

http://forum.allisonowners.com/showthread.php?t=11425&page=2

 

[thegoop]

Goop why don't you get a skid planner for the jackplate, then you want have to worry about the weld breaking.

Ok I am listening. The weld is on the top of the cavitation plate at the very back around the two corners are, where the horizontal part meets the vertical part. How would the skid planer stop that from stressing? Are you saying planer instead of the ally foil? I moved the jp down and my hole shot was a lot better today.

 

[SLOmofo]

Goop, you really need to stop and get the basics. Take the time to find exact engine height and mark it on the jack plate. Electrical guages suck for repeatability! Second when your doing the height measurement mark the trim guage for neutral trim.
Guages/sending units are sloppy. What I do is bump the up trim button to get it to neutral trim with a 3' level on top of the engines flywheel. If I miss and go to high, I trim it under and start again.
I lay an 8' level on the ground where one end extends just past the end of the prop shaft. Make it level.
I measure the pad side to side and mark the center. Measure your 3' level, lets say it's 1 1/2" across. Take a felt tip and draw a line 3/4" off parallel to the center point of the pad. Now you can hold that level against the hull straight and centered, when you hold it against that line. Is the running surface level, make it level with the trailer jack. Once it's level, now you get to trim the engine level by laying that 3' level on the engines flywheel. So the boats level and the engine is level. Now crawl back under and measure form the hull down to the 8' level and then measure the prop shaft center point. The difference is the engine height.
If your lucky you'll have someone to help with the trailer jack. It gets real old when your as old as I am having to crawl under the boat half a dozen times to get it right. But I do it cuz, if you don't your just Assuming and you know what that means.

Oh, while you there you might want to make a plum bob and see if the engine is vertical on the jack plate.

 

[thegoop]

I will check out the set up in the way you suggest. Thanks. I agree my trim gauges really are not precise and responsive enough. Is that what mechanical gauges resolve? Does neutral trim mean the prop shaft is level with the pad?

 

[allimax]

Using a plum bob is a great idea. I was wondering if there was a good way to get the motor vertical. Could you elaborate some on where you check things from on the motor or how you are doing this?

 

[Bobalouie]

You should be able to measure the adjustment points on the jackplate. If they are the same on each side, then your engine is vertical. By adjustment points, I am talking about finding a place to be able to measure the distance between the static part of the jackplate and the moving part. On my manual plate, I measure between the adjustment nut pad that doesnt move, and the adjustment nut pad that does move. I adjust them until I am less than 1/16" difference.

 

[xb03fs]

I will check out the set up in the way you suggest. Thanks. I agree my trim gauges really are not precise and responsive enough. Is that what mechanical gauges resolve? Does neutral trim mean the prop shaft is level with the pad?

I can see where a trim guage would be helpful drag racing as you get up to speed so fast. But with us fishing boats I rarely look at the guage anymore. Kinda trim by feel and gps. If it feels good and the mph goes up, I bump it again, if the mph goes down or it gets out of shape I bump it down. It seems trim is effected by so many things, load, wind, amount of chop,that I feel a trim guage is a good reference point but I think a reference point is all in a fishing boat.

No a drag race where you have to be trimmed perfectly in seconds with pretty much the same load every time I can see it being a MUST.

 

[allimax]

You should be able to measure the adjustment points on the jackplate. If they are the same on each side, then your engine is vertical. By adjustment points, I am talking about finding a place to be able to measure the distance between the static part of the jackplate and the moving part. On my manual plate, I measure between the adjustment nut pad that doesnt move, and the adjustment nut pad that does move. I adjust them until I am less than 1/16" difference.

Mine is an Allison manual jack plate. (For now) I used a dial caliper to set it measuring just like you said on both sides. What is bugging me is the strong possibility of the washers and or nuts being different measurements. The other thing would be if the engine isn't hanging the same where it bolts to the jack plate. A small difference here could make a much bigger difference down at the prop. Am I getting too anal here? The plum bob seems like a great idea to make sure things are square.
Wait a minute, after re-reading what you suggested I see what you mean, I'll re-look at that tonight!

 

[SLOmofo]

I will check out the set up in the way you suggest. Thanks. I agree my trim gauges really are not precise and responsive enough. Is that what mechanical gauges resolve? Does neutral trim mean the prop shaft is level with the pad?

I have a Stainless Marine mechanical guage, it repeats better than electric but it still has some slop thats why I only go in one direction while setting it.
Yes, neutral trim is, prop shaft even with the pad.
Remember there is a lip at the very end of the pad, I always set the level a couple inches forward of the end of the pad.

 

[SLOmofo]

" A small difference here could make a much bigger difference down at the prop. Am I getting too anal here?" NO!
All the little things add up. I know there has been more than one transom drilled off to ons side or not square. Of course not on an Allison though!

One of the main reasons the engine I have makes the power it does is the attention to all those little details, or as Dave puts it the 101's!

 

[thegoop]

Whipper I checked out that thread and few others on gearcases. Looks sweet!

 

[suicidealli]

I have ran them all. They are all a little different. They all work!!!!! Some are a little quicker on a clock. I prefer noah's, and modify it.

Roy

 

[bullwhipjkg]

I have ran them all. They are all a little different. They all work!!!!! Some are a little quicker on a clock. I prefer noah's, and modify it.

Roy

i just got one of noahs to put on my drag what kinda mods are u talking there roy or try it stock first

gonna pull my ally foil and switch over my drag also has all the plates on the back of the boat

 

[mdevrow]

Hey Bull Noahs plate works, I run mine stock.

 

[1-fastone]

I run Bmans foil.::smile:smile