Main Cap Washers

[SpeedThrills]

I'm full of questions these days while I'm putting my 360 together. I can't find installation instructions for the windage tray. So, I'm asking here.

When I took it apart, it had washers under the 4 main cap bolts that also hold the windage tray. I wondered why it only had them there.

This picture is of how I currently have it assembled. Then I read post #25 on this thread:another-surprise.429418
If I'm reading this thread (and post) correctly, I should take those washers out. They're holding the tray too far from the crank and decreasing thread engagement. It was running this way when I got it, but it seems the tray was too far from the rotating assembly.

The gap between the pan rail and the tray is about 3/16". The washers are about 1/8". Should the washers come out?

 

[pittsburghracer]

Run it if you must but I haven’t used a small block windage tray in over 30 years and my junk runs ok.

 

[SpeedThrills]

I've seen you post that before. What's your theory?

They would have to test horsepower gains on a dyno. I would think acceleration g forces would change these results.
I wonder if anyone has ever A-B-A tested one on the track? Could be done pretty quickly on a big block.

 

[pittsburghracer]

I've seen you post that before. What's your theory?

They would have to test horsepower gains on a dyno. I would think acceleration g forces would change these results.
I wonder if anyone has ever A-B-A tested one on the track? Could be done pretty quickly on a big block.

Does it keep oil windage in or out? I have my ideas on the subject. You probably know my thoughts by my postings about dyno testing by now so I won't go there. LOL.

 

[flyfish]

Run it if you must but I haven’t used a small block windage tray in over 30 years and my junk runs ok.

I was about to say the same thing....minus the 30 years thing

 

[krazykuda]

View attachment 1715378817
I'm full of questions these days while I'm putting my 360 together. I can't find installation instructions for the windage tray. So, I'm asking here.

When I took it apart, it had washers under the 4 main cap bolts that also hold the windage tray. I wondered why it only had them there.

This picture is of how I currently have it assembled. Then I read post #25 on this thread:another-surprise.429418
If I'm reading this thread (and post) correctly, I should take those washers out. They're holding the tray too far from the crank and decreasing thread engagement. It was running this way when I got it, but it seems the tray was too far from the rotating assembly.
View attachment 1715378815
The gap between the pan rail and the tray is about 3/16". The washers are about 1/8". Should the washers come out?

I run the washers on the main bolts for the windage tray, that's the way they were... The 'extra' gap that they give will not make a difference in the function of the windage tray...

The windage tray is designed to keep the 'wind' from the spinning crank from splashing the oil out of the pan at high RPM... This keeps the oil from interfering with the crank spinning and also keeps the oil in the pan and not letting it get too low to where it will starve of oil... 1/8" is not going to make a difference in that function...

The other main bearing bolts do not have washers...

There is plenty of thread in the main bearing bolts to hold the crank, that 1/8' will not weaken the clamp load on the crank... The general rule of thumb for thread engagement is minimum of 1 1/2 times the thread diameter... Ie: a 1/2" bolt will need 1/2" x 1 1/2 = 1/2" + 1/4" = 3/4" of thread engagement... I have chased the threads in the main bearing bosses and they are more than 3/4" deep....

I run windage trays on all of my small blocks and use the washers and have had no problem... I have driven one of my engines over 300,000 miles with the windage tray with the washers and haven't had any issues...

 

[yellow rose]

I've seen you post that before. What's your theory?

They would have to test horsepower gains on a dyno. I would think acceleration g forces would change these results.
I wonder if anyone has ever A-B-A tested one on the track? Could be done pretty quickly on a big block.

If you have questions about windage trays and such, you should call Kevin at Ishihira-Johnson and talk to him.

Make sure you have a pencil and paper to take notes.

I run a tray and a scraper. My oil pressure is higher than I expected. I believe this is because there is much less entrained air in the oil (air is compressible so the more air in the oil, the lower the oil pressure) and it's not like I haven't used this combo before.so I know about where I should be. I'm up 10-12 pounds from what I expected.

So before you do anything you aren't comfortable with, call Kevin. That's why I used a tray and a scraper.

 

[65 Dartman]

I don’t use a scraper but added a windage tray to my 273/235, my 340 came with one and am even adding one on a pretty stout slant.

 

[SpeedThrills]

Does it keep oil windage in or out?

They are used a lot. Must be something to them. I appreciate your view, for sure.

I run the washers on the main bolts for the windage tray, that's the way they were... The 'extra' gap that they give will not make a difference in the function of the windage tray...

The windage tray is designed to keep the 'wind' from the spinning crank from splashing the oil out of the pan at high RPM... This keeps the oil from interfering with the crank spinning and also keeps the oil in the pan and not letting it get too low to where it will starve of oil... 1/8" is not going to make a difference in that function...

The other main bearing bolts do not have washers...

There is plenty of thread in the main bearing bolts to hold the crank, that 1/8' will not weaken the clamp load on the crank... The general rule of thumb for thread engagement is minimum of 1 1/2 times the thread diameter... Ie: a 1/2" bolt will need 1/2" x 1 1/2 = 1/2" + 1/4" = 3/4" of thread engagement... I have chase the threads in the main bearing bosses and they are more than 3/4" deep....

I run windage trays on all of my small blocks and use the washers and have had no problem... I have driven one of my engines over 300,000 miles with the windage tray with the washers and haven't had any issues...

The best explanation of what they do, that I've heard, is that they stop the "driving through a puddle" effect.
I get the thread engagement. I should've considered that.
I will run it the way it was (with washers), it worked before.
Thanks

If you have questions about windage trays and such, you should call Kevin at Ishihira-Johnson and talk to him.

Make sure you have a pencil and paper to take notes.

I run a tray and a scraper. My oil pressure is higher than I expected. I believe this is because there is much less entrained air in the oil (air is compressible so the more air in the oil, the lower the oil pressure) and it's not like I haven't used this combo before.so I know about where I should be. I'm up 10-12 pounds from what I expected.

So before you do anything you aren't comfortable with, call Kevin. That's why I used a tray and a scraper.

I think I'd be in over my head if I called Kevin. lol I've seen people spend a lot of time making scrapers. I believe they (and the trays) work. However, this is a street strip engine. I probably have already over thought it. Thanks

 

[B3RE]

The washers are for the longer 3.58" stroke of the 360, so the connecting rods don't hit the tray. The 3.31" stroke motors don't use them.

The difference in stroke is .270", divided by 2 equals .135". The washers are about 1/8", or .125", times 2 equals .250", which is almost exactly the same as the stroke increase.

Soooo, leave them in there, or the rods may get cozy with the tray.