i am thinking about making my 350 into 383 or 388 stroker. Can someone outline everything i will need. it is an 89 350 1 piece rear main seal. in particular do i need a new flywheel? if it matters i am putting in a T56 in a week and a half. thanks
matt

 

hmmm
can anyone at least tell me where i can go to find out?
Thanks,
Matt

 

Yeah, the motor swap forum.

 

thanks i thought of that , but im not swapping my motor so i figured why would i post there
ill give that a shot
thanks

 

well...

 

they sell stroker kits now, look into that it comes with the crank already turned down, connecting rods ready to put on, and oh yeah you don't have to have a new flywheel, but i would get one just for the fact that you will need later on down the road

 

You can try here for some info http://www.strokermotor.com/

It really depends on whether your new engine is internally or externally balanced

 

damn it!! i'm tired of seeing people getting done wrong on a forum designed for questions in the first place!!!!

and how long have you been on a third gen camaro board and not know 87up 350's that came in thirdgens are externally balanced!!!

it's bs like this that make guys like the above never want to post on here again!!!!

he asked a simple question that over half the people here could have answerd but instead people take pics of buttons that say search and post em......

why can't people on here reguardless of rank or posts just awnser simple questions that they know!!! i thought we all were here because of the love of our car and to help other with the same love for theirs....

now to awnser you question dude...... below are a list of things you will need... if i left anything out someone feel free to add it...

1: a 3.75 stroke crankshaft for a i peice seal 350 block... i reccomend a scat 9000 series out of www.flatlanderracing.com.....

2: a set of good rods, perferably at least 5.7 inch.... again flatlander sells scat 4340 forged i beams for around 219....

3: 383 stroker pistons for what size rods you ordered... i reccomend scoggindickey part center for these... www.sdpc2000.com

4: a good machine shop will have to clerance your block for the longer stroke crank.....

5: you will need to have all the parts you ordered balanced... again your machine shop will probably be able to do this......

6: you can keep your stock flexplate and have to buy a 400 balancer...

also if your really not wanting to buy all of these seperate like trhe above person mentioned i'd suggest a kit from doughebert performance or even scat....

thank you for hearing me out and i hope others in the future will awnser things like this also...

 

Thank you badgta, VERY professional awnser, and suggestions!

 

Can you tell me how you figured out that 87 and up 350s were externally balacned? what gave you that idea?

 

how about the weight on the flexplate and balancer??????

hell all ya have to do is pick up a john lingenfelter book and read....

as a matter of fact, i would love to reccomend it to everyone who is starting on modding there motor and need help... it's very in depth and very helpful on selection and pricings

 

hey badgta, thanks for the support and answer, thats exactly what i was lookin for!
have a good one,
matt

 

No need to be a smartass, i asked a simple question. There was NO WEIGHT on my balancer and sold my shortblock so i can't look at the flexplate for you......i should look at my friends. But i dont doubt you. Just no need to be a smartass

 

Hey man, I'm building that motot as we speak, and I have the tranny you're putting in. I ordered the Scat crank from SDPC, PN is 93836000L. It is for internal balance 1 piece rear main. I also ordered the 6" Scat rods, PN 9024. These are the new PN when I ordered a few weeks ago. The assy will have to be balanced, but it should be fairly close. As you probably know we need to stay internal balance (except the little weight on the flywheel) because of the flywheel and 6 speed. Good luck

 

thanks alot jay!

 

This is what i like to see...... guys helping and commenting in a good way!!! *** i love this site lol!!

i didn't mean to be a smart ***..... and apologise therefor.... i would be happy to take pics of my balancer and flexplate if anyone wants to see....

 

All non-400 SBCs are internally balanced. The weight on the one piece rear seal flexplate is there for the lack of the eccentric on the end of the 2 piece crank. It's still not a true externally balanced engine.

 

Thank you

i knew i was right, but didn't know how to explain it and didn't want to argue

Thanks for the response

 

i'll put up a challange here....... go and get a 350 87 up crank, use and 87 up flexplate and then buy a 85 back balancer and see what happens!!!!! then you can come back and admit that gm is right......

 

I tell you what. You find me an externally balanced harmonic damper advertised for a 350 and i'll take back what i said. 350s are internally balanced. I already explained to you the deal with the flexplate. And i did just do some quick searching and couldn't find anything related to an externally balanced 350, nor does summit list a special damper for 86-up SBCs, just internally balanced, and externally balanced 400.

The funniest part is, you'e talking like an 86-up 305/350 balancer is OK for a 400. Right.

 

Keep in mind guys that "most" (except the high $) stroker kits go to an externally balanced setup with a "400" or off balance damper

PEACE :lala:

Some stroker kits if NJITIROC is interested:

http://www.speedomotive.com/

 

My 385 that I just built has an eagle 4130 forged crank in it, eagle I beam rods, and some hyper pistons (I'll probably yank them and go forged) I had the machinist try to see if he could internally balance it and he managed to do it. Not all strokers must be externally balanced (need a 400 flexplate/balancer) mines going to run a standard 350 internally balanced fluid dampner and 350 flexplate.

 

See, that's the problem I ran into. Because of the T-56 I had to stay internal balance and thought I was stuck having to get a pricey eagle full forged rotating assy until I found the crank I have. BTW, the crank isn't listed on anyone's website except for SCAT because it's brand new item, so I just called SDCP direct.

 

The rotating mass is internally balanced. I've done a million different flywheel/flexplate and harmonic balancer combos on a million 305's and 350's..

-- Joe

 

He's not right, and neither are you.

Check the GM Performance Parts catalog and it'll tell you the newer 1 piece rear seal crank engines are "externally" balanced.

If it can't run with a neutral balanced flexplate/flywheel AND harmonic dampner then it's NOT internally balanced, it's EXTERNAL!

This is exactly why it takes someone forever to find out how to build a late model 383! If someone would just explain that if you purchace a 383 crank made for internal balancing, (with 6" rods) then you can run a neutral balanced flexplate/flywheel and neutral dampner.

If they buy the external balanced crank then they are going to need to run the 3" bolt pattern, *externally balanced* flywheel and a 400 dampner.

Sheesh! Scat calls them externally balanced crankshafts! GM calls them externally balanced engine! Jegs and Summit sell the flexplates and flywheels for externally balanced late model engines! What the heck does it take to get the point across that it's EXTERNALLY BALANCED!

 

http://www.fluidampr.com/streetdampr.html

 

All ya have to do is look in a gm parts catalog like smasterson said!!!!

since 87 350's and up are externally balanced and my scat crank requires a external balance damper, i'll use my stock 89 l98 balancer!!! because their both externally balanced!!!!

 

That's the entire point. Instead of searching for the answer to this question which has been put up a million times, he wants it served to him on a silver platter. People like you don't want to ever do any legwork to figure something out. Instead, lets repeat the same crap over and over again so that we fill up the hard drives on the server. No big deal though, right? I mean, after all, it's not your money that is paying for the hardware!

BTW, you realize that there is already an ICON Motorsports that has been around for years, and that your sig is pretty misleading to people since you're not a member.

 

Speaking of hardware, Brad, do you guys need anything??
I've been upgrading a lot of stuff in my NOC, and have some spare stuff.

-- Joe

 

i think the 1 piece RMS motors are slightly external balanced. the LT1 is the same way and the stock t56 flywheel worked perfectly for me.

 

Well depends what point your looking for, the big picture is this is a message board, not a book, or a library, Tech Articles are for topics beaten like a rented mule. And I dont see any "how to build a stroker" tech articles. This topic has helped me some in info I have wanted or needed. Why? cause I am building a 383 stroker for a tuned port application (actually lt1) so I would think to ask the question in here where the Tune port people chill so I can get answers that are more directed towards my application

Maybe some want it served on a silver platter, maybe some ask the question where they can get the answer more directed towards what THEY need. It doesnt look good being an admin and attacking people for posting a legit question, in a legit board, and then complaining about server costs. It comes with the territory, if you have a message board with 20,000+ (or whatever its up to) you should expect server costs.

 

I dont know a lot about it, just what the guy building my engine has conveyed to me, but I know mine is a 400 crank, and he balanced all the internals, and I just ordered a 1 peice to 2 peice rear main seal conversion from summit.

 

I think badgta proved my point in his last post. He thinks he can use his stock 350 balancer on his externally balanced crank. As i already explained (in my first post in the topic), one piece rear seal engines only use a special flywheel due to the lack of eccentric on the crank flange. They still use a regular internal balance balancer though, which is what i meant by them not being a true external balance engine. Smasterson was simply splitting hairs since his definition of external balance includes anything that has any external balancing. Thanks for the clarification, at least it was vague and confusing enough to make badgta think you were saying that a late model balancer will work on a 400 crank. Thats why i explicitly stated the difference in my explanation rather than split hairs on non-descriptive terms.

The problem with people doing none of their own legwork is they end up taking the advice of know-nothings like badgta. There is nothing wrong with asking questions and debates and discussions. But you should have some idea of what the right info is before you ask so you can be sure that the answer you're getting isn;t off the wall. A topic like i want a 383, what do i need is way too vague and broad to be of any real use IMO. It's the kind of topic that generates more bad info than good (in my experience anyway)

 

Okay.. I'm new to 3rd Gen's , but not to the SBC. I've built probably 5 or 6 400 based engines ( retaining the 3.75" stroke, varies on 5.565, 5.7, or 6.0" rods ) I've managed to build 3 of the 383 strokers, and all have stayed together.......so far The last two were 1-piece RMS blocks.....I was confused about this issue back when I was working on the first 1-piece RMS stroker, so I went to a buddy of mine...more like a mentor. He worked as an engineer with GM's powertrain division for awhile in the late 80's, and then went on to build engine for race applications......here's what he relayed to me.....I think the main people volleying back and forth here are all right.......sort of......

The 400 is the ONLY SBC that HAS to use an EXTERNALLY balanced harmonic balancer AND flywheel. It is, by all definitions, a "true" externally balanced engine.

The pre-87 ( actually late 86 in some cases.. ) SBC ( 265,267,283,302,305,307,327,350 ... did I miss any ? ) was and is an INTERNALLY balanced engine. Meaning the balancer and flywheel are NEUTRAL, and the rotating assembly ( Crank,rods and pistons) is balanced ( somewhat closely by factory "standards" ).

When GM introduced the 1-piece RMS SBC it was SOLELY motivated by $$$$ they were LOSING by customers complaining of oil leaks ( can we say WARRANTY repairs ) from the 2-piece RMS blocks. Since a good engineer can never change just one thing they also introduced the hydraulic roller lifters ( AGAIN less valvetrain wear= less warranty claims and failures ) this change cause them to have to change the config of the block and along the way they redesigned the valve cover design ( center bolt for less oil leakage...see the pattern? ) the center intake manifold bolt angles were changed, and they had to incorporate cam thrust plate mounting provisions ( bolt holes for us simple folk ) to mount the thrust plate, which sole purpose is to keep the roller cam from moving back and forth in the block.

The redesign of the block also caused a redesign of the crank to accept the 1-piece RMS. This caused a few things.....the flywheel bolt pattern diameter DECREASED from 3.58" to 3.00". So to answer a common question, you CAN'T bolt up the wrong flywheel to EITHER engine...it won't match up. Don't ask me why I know that two of the bolts can be made to thread in

This in turn threw off the static rotating balance of the rotating assembly JUST enough to cause GM to use a flywheel / flexplate with EXTERNAL weights to offset the slight change instead of redesigning the existing connecting rods, pistons, ETC.

As for the harmonic balancer.... while a balancer from say a '87 350 will slide right on ( yeah right, you ever had a SBC balancer SLIDE right on ) an older SBC, for example a '79 305, GM RECOMMENDS that the balancer for that SPECIFIC APPLICATION be used because of differences in balancer thickness and torsional tuning attributes ( a fancy way of saying how the balancer acts when it's spinning, under load from a crank ).


So TECHNICALLY everyone was right....



Clear as mud ?


Chris

 

Duh

 

that reply about how i'm stupid, is no way to act as a moderator........

after talking to smasterson he brought up the point of how an 87 up balancer wouldn't work with my 383 crank and cause balance issues.....

so there you were right....... and i apologize for my own confusion to everyone....

but, an 87up crank by all means are externally balanced, in a way that a common netural balancer will not work.....

see, bashing i guess wont get any of of nowhere.. but, debating is pefectly ok....

and brad, why bring icon in this? does it matter? it is two different things dude!!!!

 

badgta, you tryed to argue with my entirely correct answer with incorrect information. That is classic 'i'll argue you even though i know nothing about what i'm saying' if i ever saw it. One piece rear seal balancers are not externally balanced in anyway, and a common neutral balance balancer will work. Even in the face of more proof you can't let that go can you. If you think 87-up 350s need a unique balancer, why don't you find me a summit PN for one?

This thread is over, and badgta keep in mind that you're still || close to banned so maybe you should concern yourself with being a source of good information and less about other people.