TheUrbz

Im sorry for adding yet another 383 build thread. since ive started down this road, i didnt know where to even begin on researching. Now i got honed in with a lot of information from here, but compared to in person talks and reading on other sites, i feel like my road has begun to widen, which makes for mistakes that become costly for a build like a 383. on a side note, i have no idea how you do a "budget" 383 build. i understand if you have an engine to throw away, why the hell not. but just from preliminary intro into doing this, you start skimping here and there to save a few hundred it seems youre just gonna pay it back in man hours at the least. Anyway ill give a short synapse since ive posted some of this before.

Objective: build a bulletproof 383 for my 97 formula M6 w/4.10's that will NOT see any type of track. Just making a DD beefier that sees 90% highway travel so the quickness im looking for will not be from a stop. not looking 0-60 times, more or less looking for 60-120. it does not have to pass emissions. god bless texas.

now my dilemmas. the information i have gained vs. what ive learned/ gleaned.
"383 kits are bad, parting out is better". as i understand ebay kits are bad. i have priced out parts for just the long block and im at around 6k. 2250 just for forged callis crank, rods, and mahle pistons. now they have 383 kits from summit, Lunati system with the rings and bearings advertised as balanced. now regardless that it says balanced, i would need to take this to a shop to have them confirm this and actually balance it if need be. being that, are there actually kits that are worth it? or do you just part it all out to get that warm and fuzzy?

To run this thing on pump gas, i need to keep my compression to around 9.5 to 10. using a compression calculator, im playing with numbers. figuring in deck height + gasket + bore im finding it difficult to know where to take away from. more chamber less relief, more relief less chamber? for ref, i was looking at AI's 190 or 200 heads.

More on pistons, i have...put together an idea. i am to go with hypereutectic. reason being is cast is for stock application, forged is for heavy duty. but with cast its a common point of failure for 383ing. forged is awesome, but for the daily you can (?) run into piston slap. in my case, i go from 100yds of street, to an FM road where if youre not doing 70-75 youre gonna get hit. so basically i go from drive way to 70mph and i dont want to start my car and let it idle for 10-15mins like a harley...even though i do that already for my harley. im understanding hypereutectic is forgiving and can handle my specific application.

pistons lead to rods. which im still researching. everywhere i read on here i see people recommending 6" rods, as i dive into this im seeing some 5.7" usage. im weighing on what the applications would be and what would suit mine.

Cams...hell, Compressing File...

as always, thank you for any help. And for actually reading this longwinded thing. but again, this is what i get for building helicopters before cars. "everything has to be just so damn perfect".

atlantadan

"The poor man pays twice" applies here. Do it right the first time, or you'll do it right the second.

Or you can spend another $1.3k and get a complete shortblock assembled by the best in the business. Cast crank, forged everywhere else. (And yes, a cast crank is fine for the vast majority of street cars...) If that's not an option, you're going to have to piecemeal it. Your pricing above is just how things are. If you want forged, and good quality, its not inexpensive.

I would. Trust but verify.

You can go higher and be ok on premium. I'm at 11.4:1 and others are over 12:1 on premium. And remember - you have to look at both static compression and dynamic compression. Your cam-timing comes into play here as well. Regarding piston slap, it depends on the alloy and how it is put together. 2618 will expand more so it needs more piston-to-wall clearance when cold - thereby you may get slap. The upside is that they'll take more abuse, but they're harder on cylinder walls, too. 4032's can be assembled tighter, expand less, and are quieter. Forged pistons and piston-slap do not necessarily go together hand-in-hand. There are a lot of other variables to factor in.

Reach out to Lloyd Elliot to spec a cam and possibly even heads. He'll give you exactly what you need.

TheUrbz

right and id have no problem piece mealing it. hell the kit i mentioned is $2226 so im not exactly saving money, more or less steamlining it by buying the "balanced" kit vs. what we would call rat f'ing from here and there. I see where there are people praising cast cranks, but to be honest its one of those on the fence opinions because i see the same amount of people breaking them like chicken bones. were they using it beyond its means? dont know. but it is a discussed point of failure. if i have to spend a couple hundred more to eliminate it then so be it. price is an object of course, but im not rushing this so if it requires some extra hours of overtime then that is what must be done.


as i understood it, when people say pump gas they are talking about premium. so i took that to mean to run at least premium i need the ratio i stated. if i read correctly, to figure out DCR i would need to factor in cam. and like i said, still gathering info on cams. but youre right ill have to call a guy in order to get on target apparently.

thanks for the response dan. i understand the short of it is i do have to talk to a professional builder, but id like to try and keep up with what he would tell me instead of going in there and saying "i want make go fast".

atlantadan

I've not seen many stories at all of people breaking GOOD cast cranks in street-use. If Karl spec's them as a budget-build component, I'd not worry too much about it. But you're right - spending the extra $ is peace-of-mind insurance. Its why I did what I did, too.

You said that you needed an engine that runs at 9.5 - 10:1. I was pointing out that you can go higher with no ill-effects using premium.... to a point, of course. My engine is 11.5:1 SCR, and 8.6:1 DCR. Run everyday in hot-*** Atlanta on premium. Dropped plugs down one range and been a-ok.

Lloyd will be able to help you a lot. He can also have a cam custom ground to whatever spec y'all come up with, and usually cheaper than a custom Comp grind. I called him and he took about 20 minutes on the phone to ask me on what I was doing and what I wanted in the end, with all of the specifics of my engine and the car. He then came up with the custom grind that would tick-off all the boxes for me. Can't say enough about Lloyd (or Karl, for that matter.)

TheUrbz

alright so there is some give in that ratio using premium. which i have no problem with using an extra 7 bucks a fill up. already do that for the bike. so, does factoring in the SCR and DCR together, give you an average? cause by your number that would be almost 10:1 on the nose. im sure thats wrong math but im wondering if thats why i held on to those numbers.

atlantadan

I've never heard of it working out that way and I don't think its wise to do so. Others on here may be better equipped to reply in this regard.

myltwon

iTrader: (1)

Casting is a process when done right is fine for many uses (IE oem crank), problem is most aftermarket cranks made from the casting process are done as cheaply as possible and that's where the problems arise. I have a cast eagle 383 crank snapped in half sitting in my garage from my mild na HR setup that barely saw over 6K rpm.

I'd only use a cast crank if it's an oem one. I'd spend the money on forged for this as opposed to forged pistons if money is tight. Hyper pistons are fine if you're not seeing high cylinder pressures or temps and lower cost forged pistons weigh decently more than hyper ones.

TheUrbz

and thats the story ive heard on going cheap on the bottom end. i know its costly. but in the grand scheme of this thing its really not going to make much of a difference to try to save 3-400 bucks. the layout im making is gonna cost me 15k (up to 12.8 now to be exact) for the whole car. so its not something im only gonna use to do burnouts on weekends. but im going to be thorough and im not looking to make cheap power. i suck at math so i dont even have the ability to take calculated risks.

ATK Engines

iTrader: (1)

You never mentioned your power/rpm goals? I can see you're getting allot of information from allot of different sources and it can be overwhelming.

I can save you quite a bit of $ on a quality short block or long block with name brand parts and using a 4 bolt main conversion block. Shoot me a PM and we can discuss it.

Few FYI's.

Scat balanced assembly's are very accurate. I literally use thousands a year and have NEVER had an issue.

Cast cranks are good to about 500HP, RPM is the killer, definatley not good for a bracket racer scenario.

Forged Pistons, I never see an issue with piston slap, typically it occurs with excessive side wall clearance.

For the $ differences, I recommend the full forged setup....not that its needed, but the number 1 comment I get from customers is "I should have went for more power" and they upgrade down the line. With a forged bottom end, you never have to worry about strength issues of your bottom end down the line.

Compression, we try to stay conservative in the 10-10.5:1 range. More compression can lead to detonation issues with a bad tune, poor fuel nationwide, etc. .5-1 point of compression is NOT going to pick up noticeable power.

Shoot me a PM if you want to work out some quotes.

Brandon-ATK

mred

iTrader: (5)

deleted

SS RRR

iTrader: (2)

You have options when it comes to heads/cam. I'd also inquire with Gallant Technical Performance (GTP) and Advanced Induction as well as Lingenfelter if you want to just stick with your stock cast heads.

TheUrbz

i dont quite know what my RPM goals would be exactly. ive been told that 383's rev lower, which would be a good thing since im looking for that already rolling low end power. hence why i started down the 383 route.

as for power, read a lot of posts saying somewhere north of 400 to the wheels. i know tuning seems to be an issue. but thankfully im close to Houston and there appears to be a few guys over there that do these.

as for wishing i had "more power" -no. if im above 400 to the wheels i am happy. i will not be boosting this. it will get no shot. no FI what so ever. just a ballsy DD drivers car that will not die for years to come, at the same time be completely comfortable being downshifted to run an open highway at 2 in the morning going home after a long day.


ill stick to dressing my stock heads as long as they are good to be dressed. i dont really see an advantage with sticking to an N/A and getting aftermarkets. if there is i must have forgotten about it, all my notes on heads here are for modding stock.

SS RRR

iTrader: (2)

Pretty sure GTP and AI will work with stock heads.

pantera_efi

iTrader: (1)

Hi, there is a thread, the below forum (SBC/BBC) that addresses a similar build.
This thread name is 383 SBC by "Strictly" with similar requests, just a different head.

Could the OP read that thread and comment ?

Lance

ATK Engines

iTrader: (1)

For what you're looking for I would stick with the Scat Nodular Iron Crank and Hyper pistons...be more than enough and save you $. Yes, strokers are meant for torque, but doesnt mean they cant make good HP and a higher RPM. That 400 RWHP is a bit of a stretch...its doable, but that means you're about 500 Crank horsepower....with that you need good heads, big cam and compression...and with the parts stack needed, it wont put out good vacuum for power brakes and certain EFI systems. Most 383s that are very streetable typically are in the 400-450HP/450/480tq range at the crank. Subtract about 20% for an automatic trans and about 13% for a manual for RWHP numbers.

Ill shoot you a PM with what im thinking.

KW Baraka

iTrader: (7)

No. Averaging the SCR and the DCR serves no useful purpose.

BTW.......regarding stroker LT1/4 engines; since 1998, I've had two 383ci engines in two different cars, and a 396ci and a 398ci (solid roller) in a 3rd car.

PM me if you feel the need for a "been there, done that" perspective. I can clue you in on the things I've done correctly.....and incorrectly.

KW

TheUrbz

ive looked at it. not much to go on as of yet. looks like hes still dealing with some intake switching. looks like he has his heads already that he wants, but not muck to go by on his crank or rods. ill be watching it to see what hes doing with it but it seems hes starting from a different point than i am.


thanks for lining me out man. im sure i was wrong but if i have to embarrass myself to get on the right page than so be it. i am determined to not build this engine twice.


my bad for the delayed reply. **** hit the fan at work yesterday.

pantera_efi

iTrader: (1)

There was your (OP) question not answered, "What rod 5.7 OR 6.0 ?".

The GM 400 SBC used a 5.565", good for piston strength.

My answer is the 5.7" rod will allow for a higher C.R. than a 6.0" rod.
My answer is the 5.7" rod will have greater knock resistance.
My answer is the 6.0" rod will make more HP than a 5.7" rod.
My answer is the 5.7" rod will make more Torque that a 6.0" rod.
My answer is the 5.7" rod will have a higher Bob Weight requirement.

This is with the same stroke.

The "pin-offset" used as in the OEM method, will allow for a higher C.R.

Lance

97 6speed z

KW, please copy me on this PM too!

TheUrbz

man i did not see anything about rods in that thread you directed me to. the "383 sbc Speedmaster Downdraft intake" is the only post in the sbc/bbc thread by "Strictly" that i saw.

at any rate thank you for your input. right there i see contradictory information. i was told 6" would put out more compression. im determined to find the sweetspot between HP and TQ with this build.