Balancer recommendation for cast stroker

[mbaird]

I am building a mild 408 with a cast 4” crank and my machinist doesn’t like the condition of the old balancer . Any recommendations for an aftermarket balancer ? It will be externally balanced .
Scat crank rods and pistons . Factory 5.9 flex plate .
I understand these can be hard to balance .
This is a mild (400ish) hp and probably a max of 6200 rpm .

 

[Plymouth 65]

My first choice would be a ATI Super Damper, second choice Fluid Damper. 65

 

[mbaird]

My first choice would be a ATI Super Damper, second choice Fluid Damper. 65

Will they work with external balancing ? For some reason I assume the required internal balancing.

 

[mbaird]

Maybe this one from Blueprint?
I would assume they come on their cast crank crate engines ?

Harmonic Balancer - Chrysler Compatible - 273, 318, 340, 360 and 408

 

[mbaird]

This engine is for my daily driven Barracuda. I don’t tend to beat on it very often . Maybe a trip to the track 1 or twice per year .

 

[Plymouth 65]

My first choice would be a ATI Super Damper, second choice Fluid Damper. 65

My mistake, these would be for internally balanced engines only. 65

 

[Kern Dog]

Why would an aftermarket crankshaft require external balancing? Don't they cast them to be neutral?

 

[mbaird]

Not without a lot of Mallory metal .
I did not buy this as a kit.
I had a set of icon stroker pistons and got a hair to install a 4” crank. Then I decided to get scat rods… rabbit hole …
My research shows the 4” Scat cast crank can be external balanced. I will triple check though .

 

[Kern Dog]

@RBConvert are you seeing this?
I'm working on a couple engine builds with Rich, I'm pretty sure he has a cast stroked crank. I assumed that his was internally balanced since he got a neutral balance harmonic dampener.

 

[Valman]

Will they work with external balancing ? For some reason I assume the required internal balancing.

I have the cast iron Scat stroker crank in my 360 block, they’re internally balanced. I’m running the Fluidamper, not cheap but good quality.

 

[RBConvert]

Hughes Engines balances their stroker kits, included in the price. Other shops, like Mancini Racing for instance, sell the stroker kits without a balance, but will balance them for additional fee.
I got my stroker kit from Hughes so it requires a neutral balance damper. Neutral balance flywheel too, which I picked up from SST.

 

[mbaird]

I could be wrong about this . But that Scat balancer I posted a link to says external balance for 340/360/408. Maybe you just don’t use the weights for a 408 ? I know just enough about balancing to get me in trouble .
If it can be internally balanced that is great . But I wanted to use the factory lock up torque converter from the 46rh I am installing. Will have check and see if TC or the flywheel has the weight .

 

[RBConvert]

I have the cast iron Scat stroker crank in my 360 block, they’re internally balanced. I’m running the Fluidamper, not cheap but good quality.

The Hughes damper is a Cyco System's Pro Street Performance.

 

[Valman]

If it can be internally balanced that is great . But I wanted to use the factory lock up torque converter from the 46rh I am installing

Could you not get your converter neutral balanced, then go with an internal balanced stroker bottom end?
I assume that the converter you have just has bob weights on it?
Edit: Oh, you need to check that

 

[mbaird]

Could you not get your converter neutral balanced, then go with an internal balanced stroker bottom end?
I assume that the converter you have just has bob weights on it?

Stock converter is supposed to stall around 2800 . Probably closer to 2200ish in the lighter car . This is perfect for my application . This is meant to be a strong daily driver . I have a 408 W2 Solid roller 4 sp 69 Swinger for a rowdy car.

 

[RBConvert]

Not without a lot of Mallory metal .
I did not buy this as a kit.
I had a set of icon stroker pistons and got a hair to install a 4” crank. Then I decided to get scat rods… rabbit hole …
My research shows the 4” Scat cast crank can be external balanced. I will triple check though .

If you already had the pistons and then bought the crank and rods separately then the crank is not internally balanced because the shop needs all the components to measure the bob weight. With all the components, a machine shop can now balance the assembly if you choose.
The nice thing about the damper you bought is that it can be weighted to a specific crank. I would talk to Scat about how to externally balance their cast cranks.
And yes, your flywheel has to be externally balanced as well.

 

[Valman]

Romac makes a good balancer, I had one of these on a 360 once. These were also the Summit branded balancers, not sure if they still are.
Romac Anodised Pro Series Harmonic Balancer : Steel/Alloy : suit Small Block LA 340 (Neutral Balance)

 

[mbaird]

If you already had the pistons and then bought the crank and rods separately then the crank is not internally balanced because the shop needs all the components to measure the bob weight. With all the components, a machine shop can now balance the assembly if you choose.
The nice thing about the damper you bought is that it can be weighted to a specific crank. I would talk to Scat about how to externally balance their cast cranks.
And yes, your flywheel has to be externally balanced as well.

I bought the pistons used . They only had a few passes before the engine spun a bearing . The guy came down with cancer and just threw the old 360 in due to cost . Which might be another issue since they have been balanced once already….I bought the crank and rods new separately.
The machine shop has all the components but the balancer I brought him had cracks in the elastomer ring so he recommended that I get a new one . I will call scat on Monday .

The idea was to just toss a stroker crank in the original engine thinking it would be fairly inexpensive.

 

[mbaird]

Romac makes a good balancer, I had one of these on a 360 once. These were also the Summit branded balancers, not sure if they still are.
Romac Anodised Pro Series Harmonic Balancer : Steel/Alloy : suit Small Block LA 340 (Neutral Balance)

I run a Romac on my W2 Dart . Only complaint is that they sent me a polished one . Ever try to read timing marks on a polished dampner ? Urgh … I painted it black but the timing marks don’t show up as well . Lesson learned. I hate chrome on my engines ! I even wanted the black version of TTi 1 7/8 headers but all they had in stock was silver coated ones .

 

[Valman]

Ever try to read timing marks on a polished dampner ? Urgh

Haha, that was one of the reasons I got the Fluidamper! Anodised black

 

[mbaird]

Haha, that was one of the reasons I got the Fluidamper! Anodised black

Didnt know they were sending me a chrome one . They sell a black one but was too impatient to wait for black from Australia.

 

[Johnny Mac]

Maybe this one from Blueprint?
I would assume they come on their cast crank crate engines ?

Harmonic Balancer - Chrysler Compatible - 273, 318, 340, 360 and 408

ours comes with all the weights, and the damper bolt that some want $30 for by itself.
no weight=internal. or you install the magnum weight, or the 340 weight, or the LA360 weight.

I may be late to the game already, but our damper is a pretty nice piece.

 

[mbaird]

Th

ours comes with all the weights, and the damper bolt that some want $30 for by itself.
no weight=internal. or you install the magnum weight, or the 340 weight, or the LA360 weight.

I may be late to the game already, but our damper is a pretty nice piece.

Thats right… you work for Blueprint .
Is it hard to internally balance these for you guys ? How much tungsten do they require .
My rotating assembly the same components a kit would come with from Scat.

 

[mbaird]

Late night . I was up till 2am setting up an 8 3/4 pumpkin .
Im more of a 10:00 sleeper.
Yawn …

 

[furrystump]

I run trick flow, works