[David@Vengeance]

Originally Posted by shinysun

Planning to put drop-in forged pistons.
Are there any makers to make drop-in forged with the lower CR?

We recommend our Drop In Pistons on stock rods to 850rwhp but have had guys make over 1000.

Feel Free to give us a call or you can order online.

We have our Vengeance Racing LT1 Drop In pistons on sale right now.

https://vengeanceracing.net/vengeanc...1-pistons.html

We look forward to working with you.

[Eldi Z]

Originally Posted by David@Vengeance

We recommend our Drop In Pistons on stock rods to 850rwhp but have had guys make over 1000.

Feel Free to give us a call or you can order online.

We have our Vengeance Racing LT1 Drop In pistons on sale right now.

https://vengeanceracing.net/vengeanc...1-pistons.html

We look forward to working with you.

Does C/R remain as stock with these pistons?
If not, what is the C/R going to be?

Is there a possibility to have your shop pre-gap the rings correctly in advance before shipping out, so that the job truly remains a "drop in" exercise?

[Turbo_RORO]

Originally Posted by Eldi Z

Does C/R remain as stock with these pistons?
If not, what is the C/R going to be?

Is there a possibility to have your shop pre-gap the rings correctly in advance before shipping out, so that the job truly remains a "drop in" exercise?

The VR pistons are a stock compression piston, as well as a great looking item. They are very high quality. As far as someone else gapping the pistons for you I don't think anyone will do this for you as the rings need to be fit to the actual bore that the pistons and rings are going in.

[Eldi Z]

Originally Posted by Turbo_RORO

The VR pistons are a stock compression piston, as well as a great looking item. They are very high quality. As far as someone else gapping the pistons for you I don't think anyone will do this for you as the rings need to be fit to the actual bore that the pistons and rings are going in.

Thanks for the input and confirmation.

Why would the pre-gapping of the rings be a problem in case of an as-new engine with stock bore size, which should be a perfectly known parameter?

I do not plan on a hone, since in case of my engine, it is highly likely that the OE Crosshatch is still completely visible and useful. A good cleaning (according to numerous dedicated engine machine shops) would suffice in such case when replacing pistons/rings.
Therefore the reasoning behind my quest for a simple install process (having a proper rings-gapping provided by the pistons supplier).

[parish8]

I picked up a $50 ring filer and gapped my own and have never done it before. It isn’t difficult.

[Eldi Z]

Originally Posted by parish8

I picked up a $50 ring filer and gapped my own and have never done it before. It isn’t difficult.

Good but I am a little insecure. These tolerances are quite critical and I know that there are highly accurate electronic ring filer machines (I have seen in one of the engine shops) that cost a couple of 1000 bucks and work the rings 100% perfect and from each angle. This is what I would prefer (if possible).

BtW: Did you have to hone? Was the OE crosshatch not visible inside your engine's cylinders any longer? How many miles did you have on your engine when you put in the pistons / rings?

[parish8]

You are over thinking the ring filing. You set the ring on the tool, squeeze the ring together and crank the disk. It takes care of the angles for you. Then I cleaned up any burrs with a small file. Put the ring in the bore, push it down using an old piston with ring installed to square it up. Check the gap with a feeler gauge. Then repeat till it is where you want it. The filer is not aggressive.

If you can change your own pistons you can certainly file your rings.

I did hone but probably didn’t need to. Cunningham told
Me they do a quick hone so that is what I did.

[Eldi Z]

Originally Posted by parish8

You are over thinking the ring filing. You set the ring on the tool, squeeze the ring together and crank the disk. It takes care of the angles for you. Then I cleaned up any burrs with a small file. Put the ring in the bore, push it down using an old piston with ring installed to square it up. Check the gap with a feeler gauge. Then repeat till it is where you want it. The filer is not aggressive.

If you can change your own pistons you can certainly file your rings.

I did hone but probably didn’t need to. Cunningham told
Me they do a quick hone so that is what I did.

Yeah, I guess you are right. Your way of doing it makes sense. What is your oil consumption after replacing the pistons (compared to when the motor was stock)?
If you went with the CMS solution, then you replaced the rods as well, correct? CP-Carrillo combo?

[parish8]

My oil level hasn’t moved off of full but I only have 500 or so miles on the new combo. Yes I did the rods also.

[Turbo_RORO]

Originally Posted by Eldi Z

Thanks for the input and confirmation.

Why would the pre-gapping of the rings be a problem in case of an as-new engine with stock bore size, which should be a perfectly known parameter?

I do not plan on a hone, since in case of my engine, it is highly likely that the OE Crosshatch is still completely visible and useful. A good cleaning (according to numerous dedicated engine machine shops) would suffice in such case when replacing pistons/rings.
Therefore the reasoning behind my quest for a simple install process (having a proper rings-gapping provided by the pistons supplier).

Because the difference in a low boost, high boost ring gap, and a high boost + nitrous ring gap can be within the variance of the bores. And you have a lot of faith in the bore capabilities of GM. While my bores were very close they were not to the tolerance that I would find acceptable to have "Pre gapped" rings installed. Just my opinion. Like Parish8 said get a cheap ring filer. Hell I could loan you mine.

[Eldi Z]

Originally Posted by Turbo_RORO

Because the difference in a low boost, high boost ring gap, and a high boost + nitrous ring gap can be within the variance of the bores. And you have a lot of faith in the bore capabilities of GM. While my bores were very close they were not to the tolerance that I would find acceptable to have "Pre gapped" rings installed. Just my opinion. Like Parish8 said get a cheap ring filer. Hell I could loan you mine.

Thanks man

I get it. Seems like it will be a ring filer for me too. I shall certainly get me one. I just feel a bit insecure about finding the correct gap myself. I have not done this before on GM engines (only VAGs - all small displacement 4 Cylinder engines).

[Ruhl]

How much do you think a shop would charge in labor for swapping just the pistons?

[Drsagacity]

Originally Posted by Ruhl

How much do you think a shop would charge in labor for swapping just the pistons?

I have been told that dropping the pistons will include pulling the motor. It seems like adding the pistons, it will only make sense to add the cam at the same time because the labor for the cam will pretty much be covered during the piston install.

[Joe's_cool_1le]

Originally Posted by Drsagacity

I have been told that dropping the pistons will include pulling the motor. It seems like adding the pistons, it will only make sense to add the cam at the same time because the labor for the cam will pretty much be covered during the piston install.

This video shows a little bit of the process of swapping pistons while the motor is still in. About the 7 minute 30 second mark.