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Scat Or Eagle 347?

B

bravenrace

Member
I'm looking for opinions from those with experience using both. I'm looking at two kits that Summit carries which appear equivalent, and the Eagle kit is about $200 cheaper. I've asked elsewhere and nobody seems to be able to give me a good reason why the Scat kit would be worth the extra money, and Summit says it's just a result of selling a lot more Eagle kits. I asked him why that would be and he didn't know. So what say you?


http://www.summitracing.com/parts/ESP-16003030/

http://www.summitracing.com/parts/SCA-1-94170/
 
Yeah, I noticed that, but the Eagle kit is rated for 500hp, and I'll be making around 400, so my thinking was that it would be fine. Plus, would that really account for that much price difference?
 
I agree the Eagle kit is plenty for your application. Check around too, I see AD Performance has the Scat kit for $899 with KB forged pistons, $1080 with SRPs or Mahles.
 
Summit will also price match . You might be able to save $100 or more just on that alone...
 
The Eagle kit has Mahle pistons. I prefer to buy from Summit because they are local and the owner lives in my town. My concern isn't really with the cost, but the cost difference between the two. I'm just wondering if there's that much more value in the Scat kit, or if the cost difference isn't really justified.
I originally bought a Scat 331 kit with domed pistons. I changed my mind because while I'm using 64cc chamber heads now, I'll probably want to change heads at some point, and there seems to be more options using smaller chambers, sizes that would make my CR too high.
Anyway, the Scat kit looked okay, but the crank seemed a little rough. Just some sloppy casting and machine work. It may have been fine, but it just didn't look all that good. I can't remember the brand, but it used an off brand pistons also, although they looked fine. I guess I came away not impressed or disappointed, so I thought I'd try the Eagle product.
 
I got the Scat 331 cast crank kit for my build and was satisfied with the overall quality as it came out of the box, but the machine shop commented that it was a pain to balance the assembly. They felt that they had to drill too many lightening holes in the crank. If I had to do it again, I would probably look at a pre balanced kit (assuming they probably use their better cast/machined cranks) , or take a closer look at eagle as well...
In my 331, I'm pretty sure the kit I got included KB forged flat top pistons.

Will Summit let you inspect the Eagle kit in person? That would be good if you could compare the two cranks side by side...
 
"stangg" said:
Will Summit let you inspect the Eagle kit in person? That would be good if you could compare the two cranks side by side...
Click to expand...

They have let me in the past... most recently when I had to return a Perfomer RPM intake for poor machining around the water port... I only live 25 miles from Summit and they were offering free shipping so in the era of $4 gas I took the deal... I ended up driving down anyways... arggg...
 
Yeah, they know me pretty well there, so I can easily inspect it. However, in this case it's getting drop shipped to my house even though I live on the same street! But it's returnable in any case. Comparing the cranks may not work out since they don't seem to stock the kits. I didn't go with the pre-balanced kit because I already have my balancer and flywheel and want everything balanced together. I'll likely let the order stand and check it out when it comes. I may stop by the machine shop while I'm waiting and get their opinion, since they build these things frequently.
 
In your case, a mild 400 HP 347, I'd save the $200 and buy the Eagle. The 5140 rods are plenty strong for that application and also use capscrew rod bolts. Unless you wind that thing to 7000 rpms, I can't imagine you seeing a $200 benefit.
 
my shop refused to use an eagle crank. he complained they all needed machine work to get them right. the scat parts in general didn't need as much work to get them right. that's what he claimed anyways.

my scat rods still had to be resized though.

so you may consider the higher machining costs that could occur with the eagle kit.
 
I just got a notice this morning that the Eagle kit shipped. I'll have my machinist check everything out and if the kit isn't up to snuff, I'll return it and get something else.
 
"stangg" said:
I got the Scat 331 cast crank kit for my build and was satisfied with the overall quality as it came out of the box, but the machine shop commented that it was a pain to balance the assembly. They felt that they had to drill too many lightening holes in the crank. ...
Click to expand...

That was kind of my experience as well with my Scat stroker kit. It took a lot of balance work.
 
I've got the kit and block at the machinists now. When I took it in, he said that he has more issues with crank straightness with Eagle than Scat, but that Eagle sometimes uses better pistons. I found the latter to be true in my case, where my Scat kit came with off-brand pistons and the Eagle kit came with Mahle.
He's going to check the crank out. If it's not straight, I'll return the kit, as I don't want it cut. What I don't get is how a company can get away with selling a new crank in a kit that includes bearings that needs cut before it can be used.
 
Are they machined there also? My understanding is that the blanks are from China, but they machine them here. In either case, I would think companies like these would have their own quality checks before selling this stuff. Maybe not. :shrug
 
i've read the scat cranks are rough machined in china and then finish machined in the US.

something to watch out for is the machined radius on the crank rod journals. apparently that edge is the first part of the tooling to become worn and then the radius can become too large.

i think there is a lot of people unfortunately just bolting these parts in and not really checking the details.

hopefully your parts take little to no work to get right.
 
I'm thinking you must be right about people just bolting them in. If they are really that bad, I can't see how they could stay in business if everyone was checking them.
 
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