Guys, I have some questions on building a 355 LT1 for alot of boost. Somewhere in the 18 to 22lb range for a turbo project. First question, is it possible to put this much boost on a 355 LT1 with well chosen performance parts ? I'm in the process of locating a bare LT1 block to start building the bottom end. What happens if I take the block out to 357 CI, does this present any problem with bore or stroke and durability of running that much boost or should I try to keep the clean-up on bore to a minimum (.10 over). I'm starting off with some real simple questions, so I can figure out the basics of what I can and can't do with a small cube big boost application. This site has the best info of any that I frequent and look forward to your input and help Anybody who would like to provide me with a basic outline of what they would do first to the block to prepare for this type of HP assault on engine internals please speak up.

 

Yes it is. We built cjmatt's 355 using a Callies Dragonslayer Crankshaft, Compstar Connecting Rods and Custom Diamond Pistons. The car was built with the intentions of 18-20 psi.

No, but I would make sure to half fill the block.

 

Like we talk about earlier, if your goals are for 700-750rwhp then half fill isnt necessary. I would like to hear people's experience with half fill though. he wants to street drive this in the Texas heat.

 

Just go 10 over. Leaves room for future rebuilds and promotes better cylinder sealing.

 

Realquick,
I was just reposting this info on CZ28.com to see if I can cover all my bases. I agree on the block fill situation, I just want to Half Fill just to be safe. I don't think it will be too much of an issue, hopefully ?

Eric @ Victory,
Starting out, I will want the ability to reach the target of 18 to 20 psi and if the motor makes more than 750 ish would the compstar rods take the punishment ? I'm looking into doing Pro-Grams slayed caps with ARP fastener, what do you think of those two items.

joe-96z1le,
If I just do .010 over I would have to do a custom set of pistons, right ? I was thinking .030 over to keep the price of the pistons in line with standard pricing.

 

The Compstars will handle the power you are describing, and are a very nice rod in my opinion. Arp fasteners is a must, and I use the Pro-Gram/Callies billet splayed main caps and am very happy with them. Alot of companies relabel Pro-Gram caps with their own logos.

 

I agree the more info the better!

 

Eagle H-beams with L19 rod bolts are going for $400 these days. You can't beat the price for a rod capable of 1000-1200hp.

A 2618 alloy piston is the only way to go for those boost levels. JE makes some good off the shelf -22cc ones for around $650. There's a lot of other good manufacturers like Diamond. At that level of boost, I'd get the piston tops and chambers coated for a little added safety.

A good 4340 crank will work. Spending more here will help with weight and windage more than anything. Lunati and Callies both make nice pieces.

 

Do you guys think the EAGLE rods can withstand the punishment and would I be better off saving some money on the rods and putting the extra money I saved into the crank ? I was looking into coating the piston tops, but was unsure about other items that needed a good coating. What kind of coating are we discussing ? I assume coating will reduce detonation.

 

Prevent piston skirt scuffing and galling, extending piston ring seal life with DCI MOS2/Teflon skirt coating.

Protect piston tops with a high temperature highly reflective heat barrier. Enhances flame propagation, reflects more heat into the combustion chamber and off piston tops, piston rings and lands.

 

I would go with the callies crank and rods, even though the compstar's are callies they are still chineese metal. I am almost done mocking up the trurbo kit for my car and i am not going to risk everything over saving 2k on the roatating assembly.

 

How much $$$ am I looking @ for the Callies crank and rods ? Remember this is a 355 CI at best. I'm wondering if I can actually turn 6500 ish with this much boost on a 76GTS or something similar. Wondering on cam specs how to move my powerband up a little higher than the big cube motors. Most of the 370 to 408 crowd seem to peak @ or around 5800 to 6000 rpms. I would like to extend my rpm range into the 6500 area on small cubes. Give me some insight into why you would or would not turn 6500 ish...

 

Look at thecompressor map with 355ci and see where you are at 6000rpm versus 6500rpm. If the efficiency is worse @ 6500 then 6000rpm, then maybe having 6000rpm peak power is best, and just let the turbo make the power... not rpms. Look it up on forcedinductions.com and let us know.

 

Well, looking at some compressor maps I can see where a 76mm will have me maxing it out at around 6100/6200 on a 355 CI at 20 psi. Remember this is still somewhat a guess because the maps don't take into account all the other little things. It just give you a ballpark, actually to get myself to the target rpm of 6500 to 6800 the 88mm would be a better choice. I'm wondering if the new GT-M 76mm TurboNetics will push the efficiency curve out a little bit to allow me to hit the target rpm of 6500. Does anybody know where a compressor map is for this new turbo ? I'm betting there are no maps because it is not suppose to be out till Jan. 07. The turbo should be nasty from the info I've read, 1200+ hp (flywheel) from a 76mm I would also like to get a compressor map for the S78 and S85 turbo's.

 

Yes the compressor maps shows they will support 1,200fwhp for a 76mm but has anybody made close to that with a 350 + cubic inch I havent seen any. The exhuast is what would be limiting you not the compressort. If you really want 750rwhp + look for a bigger turbo, The best thing to do would be call up forcedinduction