Shopping for a 383 stroker kit, lots of choices. I am considering buying a balanced ready to assemble kit vs one you have to get balanced. There is a little savings verses getting it done locally.
Wondering if this is a good idea? How reliable or accurate the factory balance is compared an engine builders balance....Mark

 

Get it done locally by someone you know and trust knows what they are doing. A GOOD balance job needs to be done by a pro.

 

Here's my $.02. I bought a forged & balanced Eagle kit. My machinist had installed & balanced plenty of Eagle kits & this was the 1st one he had seen that was factory balanced. He was dubious about the claimed balance, as was I. He took the balance card & said he would personally check the balance & only charge me if re-balance was necessary. I did not have to pay for a re-balance as the Eagle kit was spot on with the balance card & my machinist was satisfied. So yes, the factory balance can be spot on, however I feel much better that my local machinist also agrees. I think Eagle charges $150 extra to balance the kit, if your machinist is in the ball park it might give you piece of mind to have him do it.

 

I would put more trust a company like Eagle then a local balancer. I feel a company like eagle who does thousands a these assemblies will have the best equipment and hopefully a man who knows how to do it right. A local machine shop might have old equipment and not always the experienced help to do the job.
I went with a factory balance with my 540

 

Norval has a point. It makes a difference on the type of machinist you frequent. Mine happens to build high endurance race engines and has his own Bonneville car. I might have more faith if this wasn't the first balanced rotating assembly I had purchased.

 

Norval and Ratflinger you make a good point. On one side I would have more piece of mind with the balance done locally. But Eagle and Scat should have state of the art balancing equipment...that should yield a more precise balance job..thanks ...Mark

 

One less problem to deal with, let the company that built the kit balance it.

 

And my machinist would agree too. Like I said, my rotating assembly proved to be balanced from Eagle. I had not done this before & neither had my machinist, so we were both curious as to the accuracy of the Eagel techs. Apparently they know what they are doing.

 

Seems like Scat and Eagle own the stroker market. Looking at both and each has its merits....Scat with its 9000 series crank, Eagle seems to offer more internally balanced kits.....way too many decisions.....Both seem good though
Just need to decide, still have some questions though. Do I need a smaller base circle cam? Different oil pan (than the stock)....
Mark

 

Lots of choices. Get stroker clearanced rods and you should be fine on cam clearance with a 383 unless your going with a really extreme lift. Internal balance is a much better option. The Scat 9000 crank is cast, Forged is better, cast is more economical. Oil pan should be fine but the block will have to be clearanced for the new assembly and the pan rails may or may not have to be clearanced. I like the Eagle forged, internally balanced rotating assembly with stroker H beams W/7/16 cap screws. It is a little more $ but will allow future upgrades (Nitrous) and is pretty much bulletproof. It is a +700 HP bottom end that won't come apart on a full throttle 7000 RPM powershift missed gear.

 

I 2nd mako.....if you have the money, go with h beams and forged crank etc.......


As in my case....I just want the car to stick up for itself (it's a 79 turd)....and it'll be driven mostly on street with the occassional romp of course....and I'm not looking to make over 500hp.....so I went with the scat 9000 crank...I'm getting my machine shop to check it and make sure it's balanced....through my research I've found some cases where some of scat's products weren't to spec.....I'm getting the rods balanced anyways cause I chose the 5.7 rods that weren't clearanced for a 383.......I got a great deal on the stuff though...


yeah do make sure you get the rods clearanced for the 383....it's a little bit of work putting together, taking apart, etc. to make sure it clearances the cam.....I have an extreme energy cam with a .507 and .510 lift and it's fine...so yeah, you should be good on the cam unless you go pretty big...


I'm in the process of building this thing, that's why I'm typing alot!...and just trying to share what I've learned....hope it helps ya!



ryan

 

The bottom end of my 396 is built. It's the Eagle forged kit & the pan rails took a lot of clearancing (and this block came clearanced for 3.80 from GM), but maybe my machinist perferred max clearance instead of minimum. Normal base circle cam is fine, my lift is under .600. I'll test fit my Hamburger pan today, to make sure it fits. Now if AFR would just kick some heads free.

 

Ryan that's what I am trying to do. This 72, base engine, TH400 with 308 gears can't spin the tires!!!
This car is all matching numbers with original maifolds, carb, starter tranny etc. I need a rebuild, so I am doing a few mods and figure if I need a crank, pistons, etc might as well go for the 383. Do not plan on twisting it past 5,500 rpm (have a rev limiter) to protect the block...
Mark

 

The cast crank should be fine for your application. 6" rods would be a good idea also. Doesn't change the kit price but better angle on the rotation to reduce side loading of the cylinder wall. A scat rotating assembly would be fine and probably save you $400 to $500 vs the forged kit.

 

My machine shop clipped (ground) 2 rod bolts prior to balancing. I believe it was rods 2 and 6. I checked rod to cam clearance prior to assembly. The cam I have is .460" lift. I thinking of going to something bigger. Is the issuse of clearance with a lobe or is it the base circle? If its on the base circle, then changing cam should not create any clearance problem.

 

Thanks 63mako for your comments and advice....
I hear both good and bad on Eagle and Scat???? Hard to choose

What happens when a balanced set up is bought...are the rods clearanced? If not the factory balancing would be for nothing!!!
Mark

 

You have to check the kit specs. I believe that Eagle only clearances their H-beam rods, which only come in their forged kit. Of course I could be wrong. Call Scat or Eagle up & see if they have cast kits that include stroker rods. BTW-stroker rods are clearanced for the cam, not the block. The block still needs clearanced.

 

I would definatley call eagle or scat to double check thing before you purchase......and make sure you understand everything on it and what you are buying......I made the mistake of not looking all the way into it and bought the 5.7 rods that weren't clearanced for the cam....it's really no big deal as long as you konw what you are doing and have some feeler gauges....


2 & 6 were the ones to hit.....I believe the minimum clearance between the cam and rod is .040....I thought it was .050...so mine have .050....ha, oh well!


for you mark I believe the cast set up should be fine....if you're only going to run on the street and reving to 5500.....Mine will rev to about 6000-6500 with the cast crank.....everyone I've talked with about this says it should be fine with the little blips of 6000-6500....it's not gonna be a roadcourse car...seeing high rpms all the time for a long period of time....and will prob rarely get up there anyways....the compression ratio will be around 10.4:1 or less.....I have a few write-ups I've found on the net I can email you if you want....there was two that I found very helpful.....just let me know!

mandm1200:
if I remember right they were hitting the lobes of the cam, not the base circle....someone correct me though if I'm wrong.......





ryan

 

oh yeah, my car's a numbers mathcing too...stock tranny too...little bit of an age difference though!....I would get some headers to go with it.....


.I was in the same boat you are....my motor had been rebuilt, but never bored over.....the crank was scared too bad to reuse from no oil pressure and 6 of the rods matched and the other 2 were misc. rods......the oil had gas in it somehow....so I'm like you I figured what the heck, I'm buying a new crank and rods anyways, why not new pistons....oh, why not a stoker kit....and then I went, well, why not some heads and a new cam....so on, it just kept going....the motor will be brand new except for the aftermarket dist. that was already on it and rocker arms..........



ryan

 

bluegtp thanks for the comments....I have a 05 GP for a daily driver, not a GTP though. Any issues with the supercharged 3.8 ?
Mark