yeah thats why you see alot of people make same peak #s with 355/383. but all the lower power band is not as good with a 355. the ports size is just too small to optimize to a 383 with a decent size cam.

 

Thanks guys for the breakdown and the tips.... I just got an e-mail from Lloyd Elliot and he said for a 383 stroker lt1 to use a -5cc piston to achieve 12-1 compression, which will run well with high premium gas, also with a 2800-3600 stall and 3.42's, he said I should go with a LE2 head and cam package to still have it responsive enough on the street. He said anything bigger would take away from my lower rpm grunt....and feel sluggish when cruising on the street.....he also said a good tune will make it drive fine and still achieve maximum power....mid 11's. With suspension and lightweight wheels, and a 1.45-1.55 60' time = low 11's. So I feel this is the route I'll go with....And instead of going low, I'll get the 3600 stall in case I decide I want to go with a slightly larger cam later.....Thanks alot for the info guys.

 

I went with -16cc pistons cause I wanted to stay away from the grey area where detonation on pump gas can happen. with 12:1 compression, you better get a damn near perfect tune. I only had planned on running a mail order tune (and did up until recently) and I def. didnt want anytying to do with detonation. so I came in around 10.8 with the -16cc piston, impala head gasket (.026"?), .010" deck height (shaved deck to achieve), and stock head thickness-no milling yet. figure I can always bump some compression later by milling heads. and I was afraid of not being able to deck teh block with those -5 pistons due to too high compression. just some things to consider when making that choice. oh, I also wanted to minimize quench. thats why I went the route I did. would have been cheaper to mill the ehads, but the block being decked will never give me head gasket sealign problems since I know its square. I think my pistons were damn near .026" in the hole. add the head gasket thickness to that and thats not a good quench to fend off detonation.

 

Thats true....I know detonation is something I really don't want to deal with either. maybe I'll stick with the 11 to 1 compression or 11.25 range to be safe.....Thanks for addressing good points. thats why I posted this b/c I've never done a high power engine before, and with the $ I'm planning on spending, I want to get the most out of my combo. anything else I should consider????

 

the LE2 package is a great all around package, but I think its a little too tame. IMHO anyways. I built one for a guy on a 383 and he put down 390RWHP on the same mustang dyno I put down 320 on, but his is a t56 and mine is a4 high stall. so he's only making around 20-30 ish fwhp more then me with his pro ported heads/intake/larger throttle body. our shortblocks are identical. anyways like I said, great all around car. but if you want more power and dont mind losing a little low end torque, go LE3 or 4. or something around 240duration. cause I dont know what the LE3 and 4 cam specs are. I do know the duration of the LE2 cam btw. since I put one in.

 

I'd go bigger personally.. and I did.

I am using a Mahle -5cc piston with a zero decked block, milled heads, an a felpro 1074 gasket.

 

but you dont have the 3.75" crank. even with the offset piston pin height, the piston ends up closer to the deck compared to 3.48" stroke.

how is the driveability on your setup? I realize your 355 cid would make the cam a bit larger feeling compared the same cam in a 383. basicaly, if it has tame maners in your car, it will be a bit tamer in a 383.

 

A zero deck is a zero deck.. ie, my piston is .00 in the hole.. ie, the piston top is even w/ the block deck surface. The 3.75" crank means the piston travels further down into the hole.. not further up, that'd where the additional stroke and displacement comes from.

The combo is surprisingly drivable.. it'd be even more drivable if I had a y-pipe / catback combo as opposed to the xpipe and dumps that make it very loud.

When I had the catback on the car still it was very tame. I imagine some hands-on drivability tuning would make it even better. Keep in mind it's still on a mail order tune.

Replied to your PM btw.

 

Well see thats my problem right there....I'm torn between what to do as far as this build is concerned. I know I'd like the car to drive good on the street, with plenty of power, as well as perform good on a track. So in your guys' honest oppinion you'd pretty much both say to go with the LE2 heads and LE3 cam? at least! and 12.o to 1 compression is pretty high I think, so what do you guys' think of my original 11.5 to 1 compression ratio? Think it will all work together nicely? Thanks guys for all your help, without it I'd be screwed at this point.

 

11.5 to 1 will work fine.. and I would go w/ a minimum LE3 in a 383.

 

thats what quite a few people has been telling me...so I guess I should go with what everyone else is saying to do. Plus your times are pretty damn good and if I can reach that time or close, Man I'd be happy! So what about the stall? 3600 ok as well? I know lloyd said at least that if I go with the LE3 cam!

 

I love the 3800 stall. seems to be wild enough for the track, but tame enough to street drive all the time like I do. I still get decent gas mileage too. average 15-16. but I just changed my plugs which were worn out already. nice and beige though.
I also say 11.5:1 is a very good point to be at. no problems if you get a dyno tune.
and I also say atleast LE3 or 24x duration. since Im only guessing an LE3 is mid 23x?

javier, I realize the extra stroke is farther down, BUT, stroke comes into play in compression. its a comparison of how much volume at bdc compared to tdc. so if bottom dead center is farther down, and tdc is in the same place, thats more compression. understand yet? just go to any compression calculator and change the info all same except 3.48 cmpared to 3.75. you'll see a bid change in SCR.

http://www.kb-silvolite.com/calc.php?action=comp

 

here's a good setup for you to use.

-------------------------------------------
ENTER YOUR DATA CALCULATED DATA
Cylinder Head Volume (cc) Cylinder Head Vol=56

Piston Head Volume (cc) Piston Head Vol = 005cc

Gasket Thickness (in.) Swept Volume = .045"
Gasket Bore (in.) T.D.C. Volume =4.060

Cylinder Bore Diameter (in.) Gasket Volume = 4.030

Deck Clearance (in.) = .026" (rough guestimate. you'll hve to measure, or deck block to desired. mine was as .026" befoer decking the block to .010"

Stroke (in.) = 3.75"

STATIC COMPRESSION RATIO 11.318
------------------------------------

 

Irocss85: So would I need the dyno tune right away or could I use Tuner Cats to get it setup enough to drive it? I know a dyno tune is obviously better, but I'm just concerned with getting it to run, and not die or not start b/c the computer isn't right..... I guess I'm just trying to ask if it will even start with the stock file in the PCM?

 

I'm coming into this thread kind of late but I'll throw in my .02 in reference to cam selection...Where people tend to make mistakes is not matching the cam, converter and rear gear...This is critical to a great performing set up...I run a Joe Overton custom grind in my 383 and its only a 226/234 .568"...The times in my sig were with 3.73s and a 3600 vig...I'm at 11.2:1 and peak power at 6300 rpm with a shortblock thats 12 years old...

You have to be careful with going too big, even in a 383...If you search around here you'll see that I'm either quicker/faster than 99% of the street car 383s around here and I run a lot less cam and still have A/C, P/S, etc, etc...and a raceweight of 3600...and only dyno 375rwhp on a Mustang dyno! Beware of dyno numbers, too as they are just numbers and most folks will brag about high peak numbers, its the area under the curve where you have fun. Dynos are for tuning, tracks are for racing.

I have since gone to 4.10s and QA1s, springs, etc searching for mid 1.40s 60's and a bit more rpm in the traps (previously going through at 6000, the 4.10s should get it to 6300)...I've got 350 more miles before I can flog the car at the track (breaking in gears stinks!) and I'll be sure to post the results..

It sounds like you are researching everything and you're going in the right direction. Do lots of searches, continue to pick people's brains around here and you'll be fine...

Good luck,

--Alan

 

well, my dads car was a stock LS1 before I got to it, I ported his heads and put in a 235/242 custom cam with monstor .650 lift and it started and ran awesome with the stock tune. atleast it did WITH the map code it threw right away. tried clearing the code, just to see what would happen and big mistake. almost wouldnt run at all. ran really bad until it set the code again. I was able to put 20 miles on his car to make sure everything was ok before taking it to get dynotuned.

anyways, if you can borrow someone's pcm, or get a copy of someone else's program to toss into it, it should run ok. biggest thing is youd have to reuse the stock inj.s if you plan on starting it w/o the tune. but if you get a copy of someone else's tune with same as your new inj.s that would be a great way to get it started.

as for alan's post, great example of a good setup. I have no idea though how his car (not that Im doubting you) peaks at 6300rpm, when mine peaks at 6000 with a bigger cam. probably due to the much better heads carrying flow farther up the rpm band Id guess.

alan, I cant wait to see what your car does with the steeper gears. is that on a 10bolt? Id venture to guess that its not.

chris

 

Its a Strange 12 bolt which had the typical noisey Strange set up 3.73s and an Eaton...I just bit the bullet and went with a Richmond spool and 4.10s...All I can say is holy crap! I can feel the difference between the 4.10s and the 3.73s and the spool is not very noticable at all...probably because of the soft M/T radials...I guess my hp peak is partially due to the head flow...They are LT1 castings with 2.00/1.56s originally CNC'd hand blended by LPE in 1995 and re-ported by Eric Bradby in 2005..Flow #s @ .050 were 258int and 180 exh which Eric said were very respectable...

Again as far as cam selection I've always followed the advice of the late John Lingenfelter...the LT1s with stock casting heads love smaller durations with bigger lifts up to around .570" where any more would be wasteful. My goal was to have a street car with all the creature comforts that I could drive anywhere (no not much in the rain anymore with the spool...) and run low 11s at 120...The 4.10s/QA1 shocks/springs should make things very interesting...

--Alan

 

I was always told just to heatcycle new gears a couple times. I've never heard of a 4-500 mile breakin. I'm just curious who told you to do this.

 

Strange, Richmond, Randys Ring and Pinion, and the shop that did the install all told me to take it easy for 500 miles, change the fluid and then have at it...I'm impressed that my Richmonds are tons quieter than the Strange/US Gears they replaced...I'm just following orders...but its very hard to follow them when all you want to do is mash the gas...But I'm a patient man...

--Alan

 

same thing Ive heard from everyone. and always worked for me in the past too.