just wondering what is the best cubic inch for an aftermarket block with twin R35s also u can see Dallas performance are going with 434 which for me it is the first time i have heard of someone with that Ci and many with 408 ,,

 

z06,

I'd say you should probably just read the top 20 threads listed on the main page. This will help bring your knowledge up to a level where you can ask specific questions that will help you in your quest for high RWHP! (For example - I don't know what an "R35" turbo is. I can guess that you mean a Garret GT series but just not sure)

To answer your question, you can have whatever size motor you want - how deep are your pocket?

If you have an LS3 block you can go up to 408 CI with FI.

If you have an LS7 block you can go from 408 - 440 with ease. However, I don't recommend anything bigger than the OEM bore and stroke (427 CI) for an FI application.

If you have a short deck warhawk you can safely go up to 43x CI with FI.

If you have a tall deck warhawk you can safely go 454 CI with FI.

If you have an extra tall deck warhawk you can safely go 48x CI with FI.

If you have an LSX block you can safely go 454 CI with FI.

What's your budget? What are your goals (drivability and RWHP)? What's your platform (a Z06 ?)?

Do a little reading and answer the questions above and we'll have more recommendations than you care to hear!

 

thanks Ed, yes i was referring to the gt35r ball bearing as for the block i am going with an aftermarket rhs or warhawk with a standard deck so that puts me ta a maximum ci 43x, but as for power with ci what is the best setup obviously the the more ci the more hp but what about lag and power band does it differ with bigger ci

another question that just came up if my twin turbos are limited to 1100 whp on the 427 will a bigger ci block give more hp if so how much ??

also Dallas Performance had an lsx why did they go for a 434 if they are looking for power?


again thank u Ed but not for helping me for everyone in the Fi forum

 

Look at the Viper boys running 35r's with 522ci strokers... F.I. LOVES ci's... 434 is an easy "magic" number with parts for the LSX, you'll find many MANY LSX builds that go with 434ci's for that reason... best of both worlds BIG ci and F.I.

one addition of caution to this (as long as cylinder bore doesn't cause an issue with cylinder spacing being to "thin") which will NOT be an issue with the info listed in Ed's post...

 

again i am very interested heheh more power ?? any idea on the quote above ??

 

fafnir,

Thsi is absolutely NOT what I meant to say!

I don't mean to sound like a jerk - but I meant exactly what I said (and for very specific reasons. I've had personal experience with each block I listed!)

The numbers I listed are what I consider to be a safe bore and stroke for an FI application with each respective block. If it's an NA build, then what you say applies (because you won't stress the pistons
nearly as much as you will in an FI build). I wasn't speaking to absolute potential maximum's, I was speaking to realistic maximum's with FI.

The pistons just don't have enough skirt area/wrist-pin backing with those crazy strokes you mentioned [on a high HP FI application].

z06,

It's my pleasure to help you and everyone else!

The way I understand it - they only went 434 CI on Taylor's (Dallas Performance) build because they already had crank and rods from another motor and didn't want to start all over. (this is what I read in that thread)

When discussing FI, more CI DOES NOT equal more HP. your ultmiate HP is determined by how much CFM your turbo(s) flow.

However, the more CI you do have, generally speaking, the more power you WILL make on pump gas (vs. the same turbo on a smaller CI motor). Additionally, more CI will reduce lag which will result (given a good turbo camshaft) a nice fat FLAT power curve. Remember, area under the curve is what wins races!

I think the GT-35's are great turbos - and they are good for around 1300 HP (two of them) before you get out of their efficiency range. However, with a block like the forthcoming RHS or the existing LSX, those blocks are good for 2500-3,000 HP. I'd say go with bigger turbos if you can afford them/make them fit!

Remember - you will reach hydraulic roller limitations (lifter collapse) around 1600-1700 HP so don't think you need a set of 76's! You'd have more turbo than you need and this translates to uneeded lag. a set of 70's or 72's would be perfect with a 454 CI LSX with a Hydraulic roller setup... Minimal lag and a LOT of power for your setup!
OR if you can deal with adjusting valve-lash every 1,xxx miles, then go solid roller with the 76's and start pushing that block's limits!! (or at least getting closer to it's limits)

 

As Ed mentioned, larger displacements doesn't always equate to more power. Take for instance a stock displacement 347 CID, 2002 Z06 with all forged internals, made over 720 rwhp on my Mustang dyno. This engine had off the shelf AFR 205 heads, a very small camshaft in the 220 range, and a TTiX kit making 15 PSI of boost on the high boost setting. The same car made over 800 to the wheels on TTI's DynoJet at the same boost level. After working on the car and talking to George at TTI, I am sold on one of their kits, now its just a matter of time before I pull the trigger.

 

Great numbers, especially on a Mustang. Sounds like a true sleeper.

San

 

just to clear up, ALL of DFGDTT's parts were ordered specifically for this build, the LSX block was actually the first part ordered, then pistons, crank, rods were ordered... these parts weren't for, or from, another engine...
off topic, I know... just FYI... now back to regular programming!!!

 

i was thinking and talking to ecs about doin and ls3 stroker which would of been 416 ci if i remember correctly. why would that be a bad idea for fi.

 

Uhh ohhh, taking it to the next level huh?

 

GreekC6,

IMHO it starts pushes the ring land up a little to far on the piston - but that actually might be perfectly fine (we're only talking about 8 more CI over a 408 which IS perfectly safe). It'd be right on the edge [of what I consider 'pushing it']- but I think every one of us here likes to take it to the edge!

Doug is a more experienced engine builder than I am. If he's ok with it, then I wouldn't argue with such a small variation.

 

The LS3 with 4" stroke is pushing ring lands just the same as other LSx applications. The LS3 is usually finished with 4.065 bore (the 416 CID number) versus 4.000 - 4.005 for LS2.


Mike

 

It does not push the ring land up any higher than a 408 Ed. Same stroke (4.00) on the 416 LS3 and same as our 434 LSX. Only bore is increased.

The reason we went with 434 is because I feel it is the smart choice on the LSX block for SEVERAL reasons. First I would not recommend larger than a 4.00" stroke on a FI build. Second the bore size on the 434 cid is a great compromise between more cubic inch and plenty or cyc spacing/wall. Plus a few other details that make it attractive.

Edit: Mike beat me to it. I guess that's what I get for talking on the phone and typing!!

 

Guys,

Great catch on that! You're absolutely right about the LS3!

 

nice !! i guess 434 will be the number !! again could a t70 fit in the aps system if not how could i fit them !!!! Ed i am guessing u have done a setup with t70s how did u fit them can i buy the kit from u or even vendors if anyone out has a kit idea anything plz come and brief us !

i asked about custom kits and every shop said that they can do it some said $7G and some said $25 (wtf) i am willing to pay 11 thousand

lets be realistic 80% of custom kits turn out to be bad and break or over heat

 

How long are the bores on the LSx block? Eric recommended that I re-sleeve my bock to get stronger pistons without having issues with the skirts dropping out the bottom of the bore.

 

Z06,

I'd imagine that you won't fit 70's up front easily.

On my next build I'm going to put the turbos where the muffs are (like in an STS kit). Sure, it will be a little laggy vs having them closer to the engine- but I'll have a BIG CI engine to spool them quickly.

If anyone could do a one off BIG (70's+) turbo up front, I'd call Dallas Performance and talk to Taylor. Also, call HinsonMotorSports and talk to them. Between the two - they can do a one-off system for you.

OR - just get an STS kit with the turbos you want. As far as price, I have no idea what they'd charge you. I'd imagine it wouldn't be much more expensive than buying an already existing kit.

 

sorry but ur wrong, doug doesnt build the engines....

 

the will fit...easily with our manifolds

done it already