Performance Boats Forum banner

Engine Plate Fabrication

6952 Views 58 Replies 21 Participants Last post by  GAWnCA
I need to know all the basics of fabricating Engine plates.
What are all the tings I need to consider when fabing them . What measurements should I consider?
I have a basic template of front and back plates in some plates that I bought but are too thin. All the holes are good ,but the plates do not capture the water inlet's? Do they need to?
How do I determin the height that they need to be? Is there an overall hieght that I should start with and then trim down from there?
I would appreciate all the imput that I can get.
I have the 3/8" plate and I am ready to go to work.....Hal
1 - 20 of 59 Posts
engine plate and rail fabrication

Hey Hal,
Here is a great thread on what you need.

http://www.socaljetboats.com/index.php?topic=7137.0

p-jet
Unless your making some to reproduce and sell i would think it would be more cost efficient to simply purchase the plates. With the cost of material and any scrap you may have to end up tossing i would just think pre-made would be easier cheaper and faster.


just my .02
Unless your making some to reproduce and sell i would think it would be more cost efficient to simply purchase the plates. With the cost of material and any scrap you may have to end up tossing i would just think pre-made would be easier cheaper and faster.


just my .02
In some instantces You may be right, but I allready have the materials, I have the tools, and I would realy like the experiance of Doing the fabrication My Self...Hal
and I would realy like the experiance of Doing the fabrication My Self...Hal
I know this feeling.. and the satisfaction of doing a job your self is well worth what ever cost may be envolved.. Good luck brother and post lots of pics.
Hal, I made a set out of 1/4" wood, cut them to fit right while the motor was held in place with a hoist (like Busbys pics in the other thread). Once everything was right all I had to do was transfer the shape onto the real plates and cut them. Mine was a bit easier though because my plates where already cut, just needed the bottoms fitted to the rails.
What is the prefered type of front plate, the two piece or one piece and why?....H
What is the prefered type of front plate, the two piece or one piece and why?....H
My question is: Why would you need a one piece front plate? You think the engine block is going to flex? :)sphss

A lot of extra material on a one piece just to sit there if you ask me.
My question is: Why would you need a one piece front plate? You think the engine block is going to flex? :)sphss

A lot of extra material on a one piece just to sit there if you ask me.
I agree with Buzzard. The rear plate tales all the load. Less material = less weight.
Do I think The block is going to flexhil:)hil:)hil:)hil:)

Ok so a one piece is a waste of material. I can dig that, especially at the cost of aluminum plate. I can make a pump brace with the saved material.

Now, Is it prefered to capture the water inlets in the plates?
Do I think The block is going to flexhil:)hil:)hil:)hil:)

Ok so a one piece is a waste of material. I can dig that, especially at the cost of aluminum plate. I can make a pump brace with the saved material.

Now, Is it prefered to capture the water inlets in the plates?
Yes, I think that it is the cleanest and strongest way to go. Helps spread the load with 4 bolts instead of two per side.
2
It's owner/user preference.... Like widowmaker said, one piece is 4 bolts working together, instead of two pairs of two bolts working indepenently.

I built a one piece front, I like the looks my self, to replace the two piece I had prior.



See less See more
Ok I give up! What is the easiest and most acurate way to transfer and mark the fastener holes from the block to the engine plate.
I was trying to use this diagram, but it does not have all the info that You need (OldSquirt, I see now what You were talking about) , not to mention that when I compare the actual holes on the block to the holes on the diagram ,some of the measurements do not match. They are close ,but not close enough to ensure that all holes will line up.



For the top water outlet holes, the diagram gives a distance apart, but no reference to centerline. The actual holes on the block are prety acurate to the sheet, but they are not centered on cscl.
Same for the bottom mounting holes, there is a distance apart but no reference to cscl. For the bottom left hand holes, You have a dimention from cscl up from main register, which is only close on the block, but on the right hand side there is no reference at all to the upper hole and it is not in line with any thing.
I have been measuing and double checking a hundred times and when I thought It was all good i drill the holes and I still had to make minor adjustments to almost all the holes:mad:

If any of You out there has the trick for accurately producing the holes in the plate I would really like to know.
I am serriously thinking about remaking the front plate, just becouse the holes are not perfect, the will work the way they are , but they are not perfect!.....Hal
See less See more
Ok I give up! What is the easiest and most acurate way to transfer and mark the fastener holes from the block to the engine plate.
I was trying to use this diagram, but it does not have all the info that You need (OldSquirt, I see now what You were talking about) , not to mention that when I compare the actual holes on the block to the holes on the diagram ,some of the measurements do not match. They are close ,but not close enough to ensure that all holes will line up.



For the top water outlet holes, the diagram gives a distance apart, but no referance to centerline. The actual holes on the block are prety acurate to the sheet, but they are not centered on cscl.
Same for the bottom mounting holes, there is a distance apart but no referance to cscl. For the bottom left hand holes, You have a dimention from cscl up from main register, which is only close on the block, but on the right hand side there is no referance at all to the upper hole and it is not in line with any thing.
I have been measuing and double checking a hundred times and when I thought It was all good i drill the holes and I still had to make minor adjustments to almost all the holes:mad:

If any of You out there has the trick for accurately producing the holes in the plate I would really like to know.
I am serriously thinking about remaking the front plate, just becouse the holes are not perfect, the will work the way they are , but they are not perfect!.....Hal
I have used old mounts before...

I have seen the aluminum boat manufacturers make them (they weld stuff into the boats!) they have small lengths of threaded rod that have been sharpened on the ends to a point, the screw them into the block and use them as "punches" in the raw plates.....

I don't know if that was what you were looking for:)coffee

GT :)hand
Ok I give up! What is the easiest and most acurate way to transfer and mark the fastener holes from the block to the engine plate.
I was trying to use this diagram, but it does not have all the info that You need (OldSquirt, I see now what You were talking about) , not to mention that when I compare the actual holes on the block to the holes on the diagram ,some of the measurements do not match. They are close ,but not close enough to ensure that all holes will line up.



For the top water outlet holes, the diagram gives a distance apart, but no reference to centerline. The actual holes on the block are prety acurate to the sheet, but they are not centered on cscl.
Same for the bottom mounting holes, there is a distance apart but no reference to cscl. For the bottom left hand holes, You have a dimention from cscl up from main register, which is only close on the block, but on the right hand side there is no reference at all to the upper hole and it is not in line with any thing.
I have been measuing and double checking a hundred times and when I thought It was all good i drill the holes and I still had to make minor adjustments to almost all the holes:mad:

If any of You out there has the trick for accurately producing the holes in the plate I would really like to know.
I am serriously thinking about remaking the front plate, just becouse the holes are not perfect, the will work the way they are , but they are not perfect!.....Hal
hal call raceyindustries and tell them the width you need the plates and they will make you a bad @$z set. and they look cleen there in boulder,nv
Just get yourself some transfer screws and it will save you a ton of guessing.

http://www.victornet.com/subdepartments/Transfer-Screws-and-Transfer-Punches/2601.html

Get your motor where it is suppose to be (the hardest part) with oversize plate roughed in mounted to it then trim the plates to the rails or however you're mounting them. Do all final shaping last.

Anyone that tells you an off the shelf plate is gonna fit (correctly) without cuttin on it is pullin your leg to sell you some plates. ;) Every boat is different.

Center the crank with the pump shaft side to side then set it so the driveline is offset 2º vertically with the crank and pump shaft parallel. Clamp everything in place before drilling anything. Depending on where your pump was mounted it "may not" be centered perfectly between the stringers so you cannot precut the plate and trust that it will be correct for a particular boat. Heights are always different as well depending on what style rails and where they are mounted. Check and recheck before drilling.
See less See more
Ok I give up! What is the easiest and most acurate way to transfer and mark the fastener holes from the block to the engine plate.
I was trying to use this diagram, but it does not have all the info that You need (OldSquirt, I see now what You were talking about) , not to mention that when I compare the actual holes on the block to the holes on the diagram ,some of the measurements do not match. They are close ,but not close enough to ensure that all holes will line up.



For the top water outlet holes, the diagram gives a distance apart, but no reference to centerline. The actual holes on the block are prety acurate to the sheet, but they are not centered on cscl.
Same for the bottom mounting holes, there is a distance apart but no reference to cscl. For the bottom left hand holes, You have a dimention from cscl up from main register, which is only close on the block, but on the right hand side there is no reference at all to the upper hole and it is not in line with any thing.
I have been measuing and double checking a hundred times and when I thought It was all good i drill the holes and I still had to make minor adjustments to almost all the holes:mad:

If any of You out there has the trick for accurately producing the holes in the plate I would really like to know.
I am serriously thinking about remaking the front plate, just becouse the holes are not perfect, the will work the way they are , but they are not perfect!.....Hal
If you need, I can draw this with cad. Then you can ask anything you want and it will tell us.
Just get yourself some transfer screws and it will save you a ton of guessing.

http://www.victornet.com/subdepartments/Transfer-Screws-and-Transfer-Punches/2601.html

Get your motor where it is suppose to be (the hardest part) with oversize plate roughed in mounted to it then trim the plates to the rails or however you're mounting them. Do all final shaping last.

Anyone that tells you an off the shelf plate is gonna fit (correctly) without cuttin on it is pullin your leg to sell you some plates. ;) Every boat is different.

Center the crank with the pump shaft side to side then set it so the driveline is offset 2º vertically with the crank and pump shaft parallel. Clamp everything in place before drilling anything. Depending on where your pump was mounted it "may not" be centered perfectly between the stringers so you cannot precut the plate and trust that it will be correct for a particular boat. Heights are always different as well depending on what style rails and where they are mounted. Check and recheck before drilling.
x2
2
Just get yourself some transfer screws and it will save you a ton of guessing.

http://www.victornet.com/subdepartments/Transfer-Screws-and-Transfer-Punches/2601.html

Get your motor where it is suppose to be (the hardest part) with oversize plate roughed in mounted to it then trim the plates to the rails or however you're mounting them. Do all final shaping last.

Anyone that tells you an off the shelf plate is gonna fit (correctly) without cuttin on it is pullin your leg to sell you some plates. ;) Every boat is different.

Center the crank with the pump shaft side to side then set it so the driveline is offset 2º vertically with the crank and pump shaft parallel. Clamp everything in place before drilling anything. Depending on where your pump was mounted it "may not" be centered perfectly between the stringers so you cannot precut the plate and trust that it will be correct for a particular boat. Heights are always different as well depending on what style rails and where they are mounted. Check and recheck before drilling.
x3

Not sure if anyone has said this yet .. get some thick posterboard and make rough templates, transfer that to the aluminum. Once you cut out the rough pieces and install them, it'll kind of look like this:



See less See more
1 - 20 of 59 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top