Forgive the stupid stroker kit question.

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73Badsport

73Badsport

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Sorry I’m advance for the question. I tried google and searching to forum with no luck. I’m trying to learn more. So, do all stroker kits require machine work? I’ve got a healthy 340, but I’m looking for more out of it. Thanks in advance for any input.
 
Just so you know i know nothing but from reading this forum it seems like they need to be sent to a machinist to be balanced even if you pay more to have it balanced when you purchase it.

Others will know what is actually required.

For my money on my 5 year plan is to save up and buy one from blueprint engines and not have the worries.
 
do all strokers machine work.....does your block need to be bored?.....then it machine work no matter what....

the only additional machine work a stroker could require is clearance for the connecting rods...and that depends on what rods are used.....H beams require notching of the bottom of the bores...I beams do not....I use Scat 4340 I beam rods in my strokers no additonal machine work....
 
On 318>390 I had to use a die grinder on the bottom of each cyl where the rod bolts were hitting. I believe .080 clearance is minimum. Other than that, spend the extra few dollars to have Mancini or wherever you buy the kit balance it. It ends up being cheaper than getting it and bringing it to your own guy for the same balance job
 
70aarcuda said:
do all strokers machine work.....does your block need to be bored?.....then it machine work no matter what....

the only additional machine work a stroker could require is clearance for the connecting rods...and that depends on what rods are used.....H beams require notching of the bottom of the bores...I beams do not....I use Scat 4340 I beam rods in my strokers no additonal machine work....
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^^^This.....I also use Scat I-beams in my strokers, no clearanceing required. I'll add that Scat I-beams weigh less than H-beams, so if paired with light weight pistons the machine shop may not need heavy metal to balance, which saves quite a bit of $$$.
 
Boring, balancing, and clearancing
 
All blocks require preparation.......OR they need to be REAL GOOD to avoid the machine shop. If you're spending the jack for a stroker kit, what's a little more for the proper machine work? Honestly, in the end, only your machinist can answer that question.
 
I have read several times that the balanced that the balanced kits were very good and didn’t need anything, performed great, and lasted.

Those that have purchased kits have reported a good balance job but because there racing the scant few grams they were off was not good enough for them. I don’t ever remember the kits being reported as really bad. But the amount of perfection may not be what your after. You’ll never notice a s and dew grams out of balance. FWIW, factory balance jobs have been found Absolutely horrendous! And no one ever knew.
 
If the cylinder bores are "GOOD" and the block is known good, there is no reason a stroker kit would require any more additional machining than putting a standard stoke crank and pistons/rings in would require. You'd probably want to hone the block at a minimum but as long as you can get your stroker pistons in the diameter your block is at, you are pretty much good to go. Most would probably invest in properly prepping the block to maximize the results. For instance, if you had the block fully prepped and decided to change course and throw in a 4" arm, you shouldn't have to do much of anything.
 
rumblefish360 said:
I have read several times that the balanced that the balanced kits were very good and didn’t need anything, performed great, and lasted.

Those that have purchased kits have reported a good balance job but because there racing the scant few grams they were off was not good enough for them. I don’t ever remember the kits being reported as really bad. But the amount of perfection may not be what your after. You’ll never notice a s and dew grams out of balance. FWIW, factory balance jobs have been found Absolutely horrendous! And no one ever knew.
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Ahh see the context is something missing from the posts i read.

It was always along the lines of “i paid extra for them to balance it when i purchased it and found out when i got it it was off by X grams and had to send it to a machine shop” or similar stories.

Had no idea outside of racing it wouldnt be that big a deal.
 
Well for certain the better the job the better the result. Start to finish.

One fella I knew had some bucks to get his OE assembly balance and it was 10 grams out. “GOOD JOB CHRYSLER!!!!”

I used to see “Street Balance” & “Race Balance” a lot. What’s the difference?
Yup! A few bucks and a better job. A job that should be perfect outright! Not a choice.

For the cost a few places charge, I can’t beat it here locally. I just don’t have first hand experience.
 
I read that question as asking about the kit parts, not the block prep...
In both cases though its subjective by the builder (or assembler). I won't let anyone balance my stuff aside from "my guy". I have found some aftermarket rods when cycled, lubed properly, and torqued properly need to be resized... That is to say the bores were not round once that was all done, because the manufacturers don't always do all that before they finish machine them. The cranks are all pretty good. Some will have a little taper, better ones will be "better". Most stuff will work. But some people are more picky and normally that "picky" will be rewarded by more power, longer life, and better quality of life.
 
OK, now I will tell you the real story. First off trust no one. New parts are not always correct. Example, milodon windage tray that would not fit in side the rails of a new milodon oil pan! Witch side do you bend in to make it fit? Another example Oil pump. I bought a new Melling oil pump for my small block Mopar and found that three of the cover bolts bottomed out before contacting the cover plate. Had to re tap them! Now my scat rotating assembly. Scat part # 1-48035. Two grand $$$$$$. Three rods had to be resized on the big end. Ok not bad but then found ZERO main clearance. Thank heavens they sell OVER SIZE main bearings. And there is much more. Every one so far in this forum only talks about balancing but you need to reread over and over the post # 6 and # 7 above. Well there is many more things I could say but you get the idea. A real big thing is a Fantastic Machine Shop. I have been using the same shop since the early 70's as I used to build race motors tell I just got to damn old. If your machine shop sells the components for your motor take your block to them FIRST. Either or tell you what to get. Time and money now will save big money wasted and all the crying later.
 
Donnie514 said:
OK, now I will tell you the real story. First off trust no one. New parts are not always correct.
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BINGO!
Having your shop check out a part is mandatory IMO period! New or used.
If your machine shop sells the components for your motor take your block to them FIRST. Either or tell you what to get. Time and money now will save big money wasted and all the crying later.
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Yatzee!!!!
 
As far as balancing, i have two stroker engines running...one with scat 4 inch crank and one with a K1 crank.....scat I beam rods and KB pistons...both took a slug on mallory metal in the front and rear journal....the slug in the K1 was smaller then the Scat crank.....

I have another 408 waiting to be assembled....again 4 inch scat crank...scat I beam rods and SRP pistons that are lighter then the KB pistons...and again a slug of mallory metal....

If you buy it balanced....they used the box weights on the rods and pistons to balance the crank...dont know how it does not come with mallory in it...in fact the machine shop told me they have had to fix several of the pre balanced kits....

and for one last example got a 318 block with a scat cast crank 4 inch stroke waiting to be assembled...with scat i beam rods and Kb dished piston that weight in a 437 grams...and guess what it took mallory metal to balance it.....
 
I went with an unbalanced forged Scat crank and H beams kit. I was expecting a big hit from the machine shop for mallory metal, but the machinist said they were able to bring it into balance by removing weight from the the throws.
 
Donnie514 said:
OK, now I will tell you the real story. First off trust no one. New parts are not always correct. Example, milodon windage tray that would not fit in side the rails of a new milodon oil pan! Witch side do you bend in to make it fit? Another example Oil pump. I bought a new Melling oil pump for my small block Mopar and found that three of the cover bolts bottomed out before contacting the cover plate. Had to re tap them! Now my scat rotating assembly. Scat part # 1-48035. Two grand $$$$$$. Three rods had to be resized on the big end. Ok not bad but then found ZERO main clearance. Thank heavens they sell OVER SIZE main bearings. And there is much more. Every one so far in this forum only talks about balancing but you need to reread over and over the post # 6 and # 7 above. Well there is many more things I could say but you get the idea. A real big thing is a Fantastic Machine Shop. I have been using the same shop since the early 70's as I used to build race motors tell I just got to damn old. If your machine shop sells the components for your motor take your block to them FIRST. Either or tell you what to get. Time and money now will save big money wasted and all the crying later.
Click to expand...

Exactly. Why take chances? You dump a lot of money on a stroker kit and then just want to slap it together. No way I would do that. With an old standard bore used piston dirt road build, sure. No way would I risk that on something I spend a lot of money on. Might end up with a pile of expensive scrap metal in the driveway. That would suck.
 
rumblefish360 said:
I used to see “Street Balance” & “Race Balance” a lot. What’s the difference?
Click to expand...
Mostly, a "street balance" job gets the pistons and crank drilled to remove weight, while a "race balance" job get weight removed by grinding, and all the factory drilled holes in the counterweights welded up and ground and blended to the counterweight. Maybe the rods and pistons are matched within a few grams on a street balance, while a race engine would be spot on for each of them.
 
CNC-Dude said:
Mostly, a "street balance" job gets the pistons and crank drilled to remove weight, while a "race balance" job get weight removed by grinding, and all the factory drilled holes in the counterweights welded up and ground and blended to the counterweight. Maybe the rods and pistons are matched within a few grams on a street balance, while a race engine would be spot on for each of them.
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And the second balance job costs way more than the first.

My favorite balance job is when I can turn down the counter weights and use a very small slug of Mallory to balance. But damn, I charged through the nose for that.
 
CNC-Dude said:
Mostly, a "street balance" job gets the pistons and crank drilled to remove weight, while a "race balance" job get weight removed by grinding, and all the factory drilled holes in the counterweights welded up and ground and blended to the counterweight. Maybe the rods and pistons are matched within a few grams on a street balance, while a race engine would be spot on for each of them.
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Thank you.
yellow rose said:
I charged through the nose for that.
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Then you would make for an excellent Viking.
 
Perfect example of different levels of attention... My shop only has one balancing: Balanced. For them, it's what the above call "race". There is no "street" balancing as far as I'm concerned. That's called "factory".
 
moper said:
Perfect example of different levels of attention... My shop only has one balancing: Balanced. For them, it's what the above call "race". There is no "street" balancing as far as I'm concerned. That's called "factory".
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As far as numbers go, anything under 3 grams for a street car is more than plenty good. Trying to get any more out of it is just screwing the customer or myself.

Crank balancing is a time intensive thing. A factory balance can be 20 or more grams out and not shake. Like I said, when you get to doing undrilled balance jobs it gets expensive. Damn quick. I would never consider that for a street engine.

So, there is a difference between a street balance and a race balance. Each has its own place.
 
yellow rose said:
As far as numbers go, anything under 3 grams for a street car is more than plenty good. Trying to get any more out of it is just screwing the customer or myself.

Crank balancing is a time intensive thing. A factory balance can be 20 or more grams out and not shake. Like I said, when you get to doing undrilled balance jobs it gets expensive. Damn quick. I would never consider that for a street engine.

So, there is a difference between a street balance and a race balance. Each has its own place.
Click to expand...

No argument here.
I agree w/ the above, but a race balance job sure makes an engine mounted on an engine plate smoother . I cant even feel mine .
 
73dartswingerlover said:
Just so you know i know nothing but from reading this forum it seems like they need to be sent to a machinist to be balanced even if you pay more to have it balanced when you purchase it.

Others will know what is actually required.

For my money on my 5 year plan is to save up and buy one from blueprint engines and not have the worries.
Click to expand...
That’s what I did , need to sort out some issues with the car itself but can’t be happier with the blue print engine
 
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