friend of mine got a 400 sbc short block from them. they charged him for sonic testing, and then one day we noticed the block was leaking to the outside between the cylinders. pulled the motor( after about 100 street miles mind you) and he was going to take the short block back to them. we pulled the heads, and all 4 cylinders on one side were terribly grooved. it looks like they didnt put the finish hone on it or something. i mean, why would only 1 bank do it? so, its a good thing the block was cracked,because it trashed 4 pistons, and would have only gotten worse.

thats my personal experience with them.........

 

Did they do anything to make good on it?



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Anyone else have experience with CNC Motorsports' assembled shortblocks?
The strange thing is they build 20+ per month, but I'm finding very little out there on the quality of their builds.

I've found 3 other people who have them and gave very positive feedback.

So the score so far is 3 positive and 1 negative

 

Skirts always get scratched.. normal as long as its not excessive and there is no material transfer and your skirts are not collapsed. Anyhow you dont think the cracked block had anything to do with one bank getting tore up???????

 

skirts always get scratched.... ok i'll buy that. do cylinders get grooves the width of a penny, and all on one bank and not the other after 100 break in miles? wish i would have had a digital camera at the time. it was impressive. as for the cracked block, well, it was leaking between the water jackets to the outside. between 4&6. so, i guess idk how a crack in the watter jack to the outside, directly affected 4 cylinders, on both skirts of each piston?? im not an engine builder, but im guessing someone went to lunch during the final hone, and just forgot to finish hone when they got back ? maybe woody can elaborate on what happened ? or at least take an educated guess

 

they did work on my cousins imca mod motor. it lasted 2 races and it ended up breaking the crank, bent rods, broken pistons, trashed heads. but who is to say what made the motor let go. it was all top notch parts. also held 8500 rpms but his new engine holds that now after he had a local engine builder do it.


you get what you pay for. find a local builder with a very good name.

 

No need. I'm fairly decent with motors. Nitro motors...

Anyhow when I first read that I thought the block was cracked in half. I read it again and realized if just had a coolant leak.

So were the grooves vertical or horizontal?

 

Were there any major grooves above the top ring land? Is it naturally aspirated?

 

grooves were all vertical, and i have no idea about the groves in the ring land, as it was THEIR short block, so we didnt take it apart. we were just told to bring the short block back to them. yes, N/A motor. 100 street miles. never seen above 4k rpm.

so, what happened? because they never did say.........

 

Invest in a good torque wrench, a dial gauge, and a book.....then build it yourself! It's fun and gratifying!

 

I have no problem with assembly; the issue is good machine work that I can afford. Most anyone with a few tools and half a brain can assemble a short block once everything is machined properly and ready to go together. Unfortunately, there is not a local machine shop that I trust with this type of build.

That's why I am primarily focussed on feedback around their assembled engines/short blocks, because for me it really doesn't matter how well they sell parts its about how well their engines hold together.
They have a great price on their Dart SHP short blocks using good parts that I would take advantage of if I can establish that the quality of their work.

Thanks for all the feedback so far!

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I had a 408 shortblock built by them, but havent run it yet. I can say they were very helpful in the build. They have top quality stuff and the machine work looked great and very neat and clean place. But like I said I havent run it yet. It would be crazy for them to miss a crack in the block but who knows, hope I dont have any issues with mine.

 

Given the multitude of well known builders on these boards, many of whom will match prices, why wouldn't you use a vendor that has years of experience and feedback vs. the unknown ebay option?

 

That is an excellent question...
Although, I was not dealing with them through ebay; I have been dealing with them directly through their website and with one of their salespeople over the phone.

Do you price-match on assembled short blocks?


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