[SS_Sean]

Hey, guys. I'm getting ready to rebuild my 454. Four years ago I bought a gzmotorsports.com pump to help with an over-pressurization problem on my motor, but the motor had already been built. Now that I'm rebuilding I'd like to take advantage of any benefits the vacuum pump can offer. It's my understanding that loose rings will help with building horsepower, as there is less friction. My motor is a .060 over 454 with SRP pistons for edel RPM heads, 12.5:1 compression. Any suggestions on rings?

FYI- I did call the owner of gzmotorsports and he didn't really want to assist me with a suggestion on rings, and just said to speak with my engine builder....

 

[trmnatr]

Hey, guys. I'm getting ready to rebuild my 454. Four years ago I bought a gzmotorsports.com pump to help with an over-pressurization problem on my motor, but the motor had already been built. Now that I'm rebuilding I'd like to take advantage of any benefits the vacuum pump can offer. It's my understanding that loose rings will help with building horsepower, as there is less friction. My motor is a .060 over 454 with SRP pistons for edel RPM heads, 12.5:1 compression. Any suggestions on rings?

FYI- I did call the owner of gzmotorsports and he didn't really want to assist me with a suggestion on rings, and just said to speak with my engine builder....

You are pretty much limited to what your pistons will accept unless you plan on custom pistons or pistons with a low drag ring pack

 

[SS_Sean]

So Sealed Power has one set of rings for my pistons??

 

[Mike]

Not quite what he said.
Your pistons will dictate the ring package you can run and you didn't say what the ring grooves are so can't really tell you what's available.
Here's a listing of Speed Pro's from Flatlander so you can see the groove sizes/tension
http://www.flatlanderracing.com/index.html
But as suggested ,check with your builder.

 

[SS_Sean]

Now I understand. Basically I'm looking for a low tension ring, correct?

 

[engineguy]

Low tension oil ring assemblies are available in 3/16" and 3.0MM widths. Ultra low tension (2 to 4 lbs) rings are generally limited to 2.5MM and 3.0MM widths. A vacuum pump must be used with ultra low tension oil rings, for best results.

Just changing to ultra low tension oil rings and adding a vacuum pump will not result in much measureable horsepower gain. These parts need to be used in conjunction with the proper combination of parts such as lightweight rods & pistons, small journal crank pins, etc., etc. and will show favorable results in purpose-built race vehicles.

 

[letsrock]

Sean,
We installed a gzmotorsports pump this spring on a 496, good product, but not much support after the fact (in our case). We too had issues w/excess pressure, the pump did a great job with it, even took care of the minor oil leaks. We run it @ 12 inches wot. The research we did came to the same conclusion as Bill stated, not alot of gain without changing out the bottom end of the motor to lighweight parts, (which can be a few bucks). Good luck & hope it works for you.

 

[SS_Sean]

Thanks for the info....

I contacted my local engine builder and have a game plan worked out that should net some small gains.

 

[GuysMonteSS]

I was just curious as to why the emphasis on light weight parts ?? Would there be advantages to using a vacuum pump on a mostly street driven car ?? Or would the greatest benefit be at wot ??
Guy

 

[letsrock]

Guy,
I am not an engine builder or pretending to be one, it was our understanding that to get the full potential of a vacuum pump a light weight bottom end and low tension rings would be the best way to get there. We don't have those in our 66, but we do get the vacuum we need to help keep the unwanted vapors (running methonal) out of the engine and free up the excess crankcase pressure that was contributing to the small leaks we were having. As far as street cars go, I have seen a few switching from the valve cover to header e-vac systems to the pumps because of the exhaust systems on a street car. I would'nt say that the greatest benefit would be @ wot as the pump is e-vac'n even at idle, we pull 5 inches at idle. Some guys are even running the electric pumps so after the run they can shut down the car and leave it on as the car cools. I'm not an expert on this, but hope it helps.

 

[M.Maner]

Guy,I'm just guessing here but I have to believe the reference to light weight parts would be indicating higher rpm use,where the low drag rings and vacuum pumps would show more benefit. Again,just a guess.
Mike

 

[engineguy]

Mike,
That is correct, light weight parts and low tension ring equal high RPM. High RPM creates pressure in the crankcase. The role of a pan evacuation system or a vacuum pump is to relieve this pressure build up in the case. If the engine has internal leaks, it will continue to leak even if a vacuum pump is used. Pan evacuation/vacuum pump is not necessary in "most" street driven engines which are properly built. The street vehicle that is regularily shifted at 7500 RPM may need a pump though.

 

[dyno jonn]

You will need to change out your timing cover seal and rear main seal to ones specifically for use with a vacuum pump system too. If you don't, you will pull air in past the seals.