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Scat Stroker Rotating Assembly Kits

Posted: March 19th, 2014, 2:50 am
by jeepxj3
Has anyone used these kits?
They come with crank, forged rods, forged pistons, bearings and balanced.
Flatlander Racing has them for $895. Is there any other source?
Anything to watch out for?

Re: Scat Stroker Rotating Assembly Kits

Posted: March 19th, 2014, 3:14 pm
by hurleygo3
I have a SCAT crank and forged rods sitting in the garage waiting to be built. The kit your looking at for $895 doesn't come with the rods. The only issue I saw with the complete stroker kit from SCAT is the deck height with the KB944 pistons. That's what pistons they are using. It puts it at .025

Re: Scat Stroker Rotating Assembly Kits

Posted: January 14th, 2015, 4:57 pm
by YJ Genie
Hurleygo3,
Where do you come up with the .025 deck height? Is that piston protrusion or recess? Is that on a particular block? Many Years of engine work and research has shown that @ 5000 rpm you are likely to see .030" rod stretch.
With +.025" piston protrusion and .030" rod stretch(.055" @ 5000 Rpm) combined with .045" head gasket will result in .010" interference with cylinder head.... I have to believe Keith Black and Silvolite have a better handle on their products than that.
Now if its -.025" recess, that may be a problem. Is that calculated or measured?
I hope you are wrong, cause I just ordered the stage 3 kit. with Scat rods and crank and IC944 pistons

Can the deck on a 1998 '569 block be cut that much safely? .. Sure hope so!

Re: Scat Stroker Rotating Assembly Kits

Posted: January 14th, 2015, 6:34 pm
by jsawduste
25 in the hole with 4.0 length rod.

The chambers on these engines like (demand) a tight quench/squish. Common is to have pistons with a revised pin height to give a zero deck. Combined with a compressed .043 gasket they work fairly well.

Re: Scat Stroker Rotating Assembly Kits

Posted: January 14th, 2015, 9:30 pm
by Cheromaniac
YJ Genie wrote:Many Years of engine work and research has shown that @ 5000 rpm you are likely to see .030" rod stretch.

Depends on the material that the rods are made from.

With +.025" piston protrusion and .030" rod stretch(.055" @ 5000 Rpm) combined with .045" head gasket will result in .010" interference with cylinder head.... I have to believe Keith Black and Silvolite have a better handle on their products than that.
Now if its -.025" recess, that may be a problem. Is that calculated or measured?

Give or take a few thou depending on production tolerances, the IC944 pistons end up 0.027" down the hole at TDC in a 4.0L block with a 258 crank & 4.0L rods. Add a compressed head gasket thickness of 0.043" and you end up with a quench height of 0.070". Even if you reduce the quench height to 0.040", you'd still have 0.010" to spare between the piston crown and head at 5000rpm.
Keith Black quote a 4.0L block deck height of 9.433" on their site for the IC944/945 pistons but since the actual block deck height is 9.453", I guess K-B expect you to have 0.020" milled from the block when using these pistons thus leaving them only 0.007" down the hole (with a quench height of 0.050").

Re: Scat Stroker Rotating Assembly Kits

Posted: January 15th, 2015, 5:17 am
by jeepxj3
A better 'kit' is use the Scat crank and rods and add the Bulltear pistons.

Re: Scat Stroker Rotating Assembly Kits

Posted: January 28th, 2015, 11:39 am
by YJ Genie
Bulltear piston?... I'll look into it. Thanks for direction...

Re: Scat Stroker Rotating Assembly Kits

Posted: January 28th, 2015, 11:41 am
by YJ Genie
I would like to thank each of you for your input. I learn something new every day.
Gene S.

Re: Scat Stroker Rotating Assembly Kits

Posted: January 29th, 2015, 5:06 am
by jeepxj3