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3,960 Posts
Discussion Starter · #1 ·
Well.......after talking to a few people about the strokers that Coast high performance engines builds.....I have come to a few conclusions....

1. A business contact informed me that after running a 347 stroker from these guys....that it also ate a main bearing very quickly....After the tear down we saw that the builder had left a
rag of a certain color inside a cylinder. part of it was out of the
exhust port and half was still inside. (whatever was left of it)

WHen the managaer was confronted he asked what color rag it was that was stuck....he then denied that they even use that color rag in that shop. (how convenient)

I then found out that they used a Scat crank...(which is very inexpensive but leaves a ton to be desired in the quality dept.)

The tolerances for the mains were SO off that the front stem of the crank (where the damper and timing sprocket mounts) was wobbling up and down so bad.... (this is before the teardown)

We also saw that the bottom of the bore skirt was notched in a very quick and lazy way......

The pistons used are of the Hyper E type and are made by KB
which we all know have a skirt problem.....if it rocks in the bore
the skirts have a tendency to stick out too far hence scratching the bores.....

Upon the teardown of this companie's un guaranteed "high performance" motor I saw that ALOT of components were of cheap quality and poor workmanship. The poor workmanship of the engine itself was also evident.

I don't mean to flame any vendor, I am merely stating the facts and what I saw in hopes to pursuade a VMFer that wants a stroker, not to go the cheap way.

It is also evident as to why they won't stand behind their product.

As for the 347 stroker I built, it is still running and we are still fine tuning the Holley 750 carb to squeeze even more hp and torque out of this monster.

The carb guy told me that we can get up to 500hp and ft lbs
by "slowing and widening" the intake charge
He does this by radiusing the boosters and creating a wider
funnel, so that the intake plenum velocity doesn't cause the charge to hit the plenum floor.....avoiding a wet condition....

We will also re-dyno the stroker to see what results will be yielded.

so far upon removing the oil pan to inspect the journals and boire skirts.....I haven't seen any scoring of any kind....

Break in period has been attained and the sweet spot of this engine still needs to be found.

I will be posting results later on.

As for the thermal coatings.......when the engine was on......
the intake got all icy.

The intake was RMI prepped and coated with heat dispersant coating. The piston skirts were coated with a dry lubricant coating
to enhance anti fricition properties to this engine.
Heat dispersant coatings on the oil pan, timing cover, intake manifold, thermostat housing, water pump, oil cooler adapter,
cyl heads, and radiator have all helped this beast run up to 15 degrees cooler under the hood. This can equate to more horsepower and longer belt and hose life.

Using a roller cam, roller rockers and an electric fuel pump has also reduced friciton thus parasitic heat under the hood..... all adds up to impressive numbers.

2,032 Posts
WE all know that KB hyper-e pistons have a skirt problem ? I haven't found that to be the case. Unless you happen to be talking about their specific 347 piston. That's otherwise a pretty broad statement to make without backing it up. Two friends of mine (who have that same piston, by the way), beat their cars pretty hard as a rule, and haven't had any problems. They are not Coast engines, BTW..

Some reported other issues with CHP 347's and others have said their's are okay.
Personally, I would have (and did) avoid the 347 for other reasons. The pistons
were not part of it..

3,848 Posts
"I then found out that they used a Scat crank...(which is very inexpensive but leaves a ton to be desired in the quality dept.)

I've been researching stroker kits for a 331 build for quite sometime. You are the first person I have heard question the quality of the SCAT crankshaft. I would very much like to know the part# of the crank you are referring to, and whether or not it was properly prepared and balanced by CHP. I have heard differing opinions on other less expensive stroker kits (Cat for instance), but I have first hand knowledge of the SCAT Series 9000 crankshaft and what it will put up with.

I see you prefer Eagle products. More than once, I've heard about quality concerns with their cranks.

3,960 Posts
Discussion Starter · #4 ·
I had a 302 (normal 3 inch stroke) with KB pistons built

It was ok for 60k miles then the piston skirt broke and left fragments of the piston skirt all over the rotating assembly.

KB pistons in general have a non-squared shape...they atart off nice and funnel down towards the middle, and as you look down the piston skirt, they expand (they did this to try and keep the piston square in the bore) and in some cases as with the stroker set up it rocks too much in the bore, scratching the bore wall.

This turns into premature wear...and engine failure, alot of side loading.

It ma be different with other motors due to different compression heights.....and yes I was too general about it.

I had that 302 redone with an eagle crank, JE pistons and
I haven't had a problem with it yet....(it sits at 72k miles.)

WHen you hear about too many follies and see the work
from a shop with your own eyes, you'll tend to stay away from their products.

I for one.....would rather have you have a reliable, bang for the buck....

I don't mean to be imposing, I just have my preferences, that's all.

Yes, I have had some very good experiences with Eagle Specialty products.

Their rods and cranks are of very good quality.

I know of so many shops that won't even mess with a scat crank.
I know this because of shopping around for a shop to build my stroker......

I have also had some friends that have had bad experiences.....thus I am sharing some bad experiences with you guys to try and save some time and $$$

116 Posts
I have a CHP 408 stoker in my 351W and the engine builder (well known professional mustang 5.0 racer in Boston) told me that he was impressed with the quality of the parts in their kit. CHP makes 3 kits ranging from inexpensive cast stuff for less agressive motors to all forged parts (crank, rods, pistons, etc.). I paid a little more and got the forged parts with a girdle. The 69 block is bored .040 over and makes 10:1 compression (she runs smooth and quiet, revs to 6k all day without a hicup and doesn't use a drop of oil). The quality of the build is as important as the parts and I wouldn't cut corners on either one but I think CHP makes a good kit if you opt for the forged parts. Just my $0.02.


3,848 Posts
Everyone is entitled to their opinion.

Having said that, I might point out a couple of flaws in your premise.

Eagle and SCAT crankshaft prices are almost identical throughout their respective line. Whether you talk retail or best price, they are highly competitive price wise.

You also state not a single shop would use a SCAT crank. Just the law of averages makes this hard to believe. I truly think you or your shops are confused between SCAT and CAT. Cat is in fact a cheaper, lower quality, off-shore product with a reputation that is not good.

The fact is, that no matter the product, if there are enough made, a bad one will make it out the door from time to time. A competent engine builder will always double check tolerance and measurements before assembly. Based on what I have seen about CHP, I'd sooner suspect poor quality control in assembly. Not an inferior crank.

I have personal knowledge of a SCAT Series 9000 crankshat that made over 1600 passes in the 10 second range before it went south. And I have yet to find a shop that flat wouldn't use one.

I'm still buying a SCAT stroker kit.
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