368 sleeves and pistons??

[Paul Workman]

I'm looking to LA Sleeve for info on 4.0" sleeves for the LT5, and am totally open to what and where to get pistons for the 368 conversion that work with the stock rods. Any info on which sleeve to order (fm LA Sleeve) or where and what part numbers for the pistons would be helpful. (The idea of a group purchase/discount comes to mind!)

That said, money is an object these days...:rolleyes: So, depending on what it would cost to get into a 368 will determine when that will be.

What say you gurus??

P.

[Polo-1]

LA's $1100.00
JE's $1600-2200.00 (options)
Rods/Bal. $500.00
Block hone/clean $450.00

These are just quick #'s for you.
Stock Rods must be trim at the top end. Then everything balanced.

[Paul Workman]

LA's $1100.00
JE's $1600-2200.00 (options)
Rods/Bal. $500.00
Block hone/clean $450.00

These are just quick #'s for you.
Stock Rods must be trim at the top end. Then everything balanced.

Excellent info!:thumbsup: Thanks! I read your PM first, but now with this info, I know what direction to head...NEXT winter (2010-2011) project! That will give me time to bone up - beginning with pulling the motor now to fix whatever and time the cams. (Silly me...I still wanna drive it some this season! I've put less than 1000 miles on 'er this year so far, and that is very sad!

P.

[Kevin]

i need to learn to read. nothing to see here

[Aurora40]

Wow, doesn't really sound like "while you are in there" kind of money. $4k just in parts?

While a 368 if you needed to freshen the motor anyway sounds cool, do they really make that kind of power for a "while you're in there" thing? It's only a 5% increase in displacement. Presumably it's about a 5% increase in power, or maybe 20whp. Is that about right?

[jonszr1]

from what i understand, the increase is 35 to 40 .due to the unshrouding the valves

[blackjack]

paul,
i have a set of used pistons for a 368,in very nice shape(je)
pm me if interested
bj

[Polo-1]

Presumably it's about a 5% increase in power, or maybe 20whp. Is that about right?


Most 368's also are 12:1 comp ratio.
With the 4" bore helping the unshrouding, the bump in compression helps it too.
Most 350's 490-510hp
Most 368's 530-560hp 560hp from added cams.

[lbszr]

Most 368's also are 12:1 comp ratio.
With the 4" bore helping the unshrouding, the bump in compression helps it too.
Most 350's 490-510hp
Most 368's 530-560hp 560hp from added cams.

Can pump gas still be ran with the 12:1?

Anybody know what the highest CR and still be on pump gas? Just
curious.

[Polo-1]

All builders run 11.75 to 12.25:1 and run pump gas.

[flyin ryan]

Can pump gas still be ran with the 12:1?

Anybody know what the highest CR and still be on pump gas? Just
curious.LT-5 specifically or just any engine in general?

[lbszr]

LT-5 specifically or just any engine in general?
Was just curious on lt5, found out the hard way 383 with hypereruetic keith black pistons dont hold up up to 10.5cr in a boat on pump gas, it still lasted quite(years, roller cam went in, it lasted 5 hours) a while till it broke the top land off the piston and wasn't room in cyl for it at 6000.

[blackjack]

kb pistons will do that once in a while,if the rings are set too tight
bj

[rkreigh]

LT-5 specifically or just any engine in general?

12-1 is pretty high for a "non lt5" engine

the new direct injection and efficient combustion chambers help

as does the variable cam timing

the lt5 of course benefits from an efficient clover leaf combustion chamber and a dished piston at high CR and is pretty detonation resistant even at high CR

[blackjack]

you must also remember that you reach a point of diminishing return,with compression ratios;
you get more hp by going from 8 to 9:1 than you get
going from 11 to 12:1
bj
91/1735
98 c5
2002 z06 w/procharger