Rotating Assemblies Up To 468 CID

[frey.199]

I was talking to a guy from Texas Speed on the phone about getting a new engine rotating assembly. He told me the biggest I could go to was a 416 CID, without changing anything. Just purchase and put in. I was thinking I saw some other people doing 427 on here too.

My question is, does anyone know what is required of the engine (or anything else) to go to a 468 CID? The guy explained some but I was a little confused. He mentioned re-sleeving I think (not 100% what's involved in that). The options above a 416 seemed to be a wide variety between a 416 and 468. Any input also would be greatly appreciated.

[AGM 1LE]

A 416 would be the stock 4.065in bore with a 4.0in crank. I think the 427 would be a 4.1in crank with the cylinders honed to 4.070in. To get to 468 you would for sure have to re-sleeve and stroke it.

[frey.199]

Originally Posted by AGM 1LE

A 416 would be the stock 4.065in bore with a 4.0in crank. I think the 427 would be a 4.1in crank with the cylinders honed to 4.070in. To get to 468 you would for sure have to re-sleeve and stroke it.

I found this link https://www.onallcylinders.com/2017/...e-performance/

If you scroll down it says they don't recommend boring over 4.080 inch, but leaving them as thick as possible when running boost. I'd like to SC one day. I wonder if changing my rotating assembly would be no benefit to me then or if it's due to issues with integrity to the structure of the block by thinning them out?

[gtstorey]

I think the 468 also requires a tall deck block.

[frey.199]

Originally Posted by gtstorey

I think the 468 also requires a tall deck block.

Like a completely different block? TSP was showing it compatible, but I'm not sure how accurate the web page is.

[gtstorey]

TSP shows the 468 as being for tall deck blocks, so not an LS3 block.
https://www.texas-speed.com/p-1035-t...-assembly.aspx

The largest they go on a short deck block is 454 but I think that is still on an iron block.
The 438 or 441 are supposed to work with an LS7.
The largest they list for the LS3 is a 427/429 ci.

[frey.199]

Originally Posted by gtstorey

TSP shows the 468 as being for tall deck blocks, so not an LS3 block.
https://www.texas-speed.com/p-1035-t...-assembly.aspx

The largest they go on a short deck block is 454 but I think that is still on an iron block.
The 438 or 441 are supposed to work with an LS7.
The largest they list for the LS3 is a 427/429 ci.

Oh yea! You're right, thanks for pointing that out to me.

[acammer]

Originally Posted by AGM 1LE

A 416 would be the stock 4.065in bore with a 4.0in crank. I think the 427 would be a 4.1in crank with the cylinders honed to 4.070in. To get to 468 you would for sure have to re-sleeve and stroke it.

4.065x4.000 is a 415, need that 0.005 overbore to get to a 416. We don't usually recommend going beyond a 4" stroke because you start pulling the piston out the bottom of the cylinder, and it'll rock a little, and that will wear things. For a race motor, have at it, but for the street the 4.00" stroke is where you usually want to quit.

You can get more bore with resleeving, etc. My first question would be what's the application here... ie. why do you want to get to so much displacement?

[frey.199]

Originally Posted by acammer

4.065x4.000 is a 415, need that 0.005 overbore to get to a 416. We don't usually recommend going beyond a 4" stroke because you start pulling the piston out the bottom of the cylinder, and it'll rock a little, and that will wear things. For a race motor, have at it, but for the street the 4.00" stroke is where you usually want to quit.

You can get more bore with resleeving, etc. My first question would be what's the application here... ie. why do you want to get to so much displacement?

More power. However I think I've been looking at things wrong. I would like to boost down the road and I'm reading that I would need lower compression numbers for doing this or E85 for high compression/high boost. Am I reading that right? The stock engine 10.5:1 seems high compared to the recommended 8:1 or 9:1 compression ratio for boosting a car. Seems like I have two options as far as boosting, but which will have better results? Or does the 10.5 work? Which has the least risk for detonation? Etc. Thoughts?

[sixty9fordkiller]

i would stay with the stock displacement for boost and spend the money on a solid forged bottom end instead

Sent from my SM-G975U using Tapatalk

[frey.199]

Originally Posted by sixty9fordkiller

i would stay with the stock displacement for boost and spend the money on a solid forged bottom end instead

Sent from my SM-G975U using Tapatalk

You think the 10.5 compression will work then? The rotating assembly is the main determining factor for compression, right?

[Black_SS10]

Originally Posted by frey.199

You think the 10.5 compression will work then? The rotating assembly is the main determining factor for compression, right?

You can change the compression by simply changing the rotating assembly as a whole OR by changing parts of it.

10.5.1 static compression (SCR) will be fine for boost. Look at what your dynamic compression (DCR) will be. This may help you.

https://www.enginebasics.com/Advanced Engine Tuning/Static vs Dynamic.html

[lemontwist]

Originally Posted by acammer

4.065x4.000 is a 415, need that 0.005 overbore to get to a 416. We don't usually recommend going beyond a 4" stroke because you start pulling the piston out the bottom of the cylinder, and it'll rock a little, and that will wear things. For a race motor, have at it, but for the street the 4.00" stroke is where you usually want to quit.

You can get more bore with resleeving, etc. My first question would be what's the application here... ie. why do you want to get to so much displacement?

what is the application great question! in these days of mega power cars off the lot we seem to forget what a 9 second car was because of what it is now.
what is usable/reasonable power for the street. it's not far fetched for LS motors can hit 1000HP boosted without big displacement.
all BS and jokes aside in a street car 600hp is a chit load of power on the street.

[frey.199]

Originally Posted by Black_SS10

You can change the compression by simply changing the rotating assembly as a whole OR by changing parts of it.

10.5.1 static compression (SCR) will be fine for boost. Look at what your dynamic compression (DCR) will be. This may help you.

https://www.enginebasics.com/Advanced Engine Tuning/Static vs Dynamic.html

Thanks for this. Did not know their was a static and dynamic and that you go by the dynamic compression, not the static. Called TSP back and looks like I'm running about 7.83 CR with their cam installed. I guess my next question would be, if I run boost, at what point do I need to change pistons, etc to something forged?