Scat 347 stroker kit?

Mike Sattelberg · #1 (**permalink**) 11-20-2003, 10:16 AM

I am getting ready to build 302. The best deal I have found for a 347 stroker kit is through Northern Autoparts. They list a Scat 347 stroker kit for $699.99. It comes with....
-9000 series Scat crank
-4340 forged I beam Scat rods
-Hypereutectic pistons from KB
Has anyone used this setup and how is it working. I am told that the rods are floating rods? It sounds like a pretty good deal.

Mike Sattelberg
FFR cobra in 2006

Excaliber · #2 (**permalink**) 11-20-2003, 10:36 AM

I don't like the Hyper pistons. I'm not sure WHY the main manufacturers have gone that way. Hypers are NOT stong enough for Nitrous, maybe there OK for other use?

E-Bay 347 stroker kit for you to compare prices here:

Item number 2443441295, price $979

http://cgi.ebay.com/ebaymotors/ws/eB...tem=2443441295

Note on the e-bay package: Forged pistons. $200 extra for "balancing". At the $699 price your looking at I gotta wonder what there "leaving out"!

Ernie

PSB · #3 (**permalink**) 11-20-2003, 10:42 AM

Quote:

Originally posted by Excaliber

I don't like the Hyper pistons. I'm not sure WHY the main manufacturers have gone that way. Hypers are NOT stong enough for Nitrous, maybe there OK for other use?

Tigher tolerances, better oil control, cheaper to manufacture are all reasons that the manufacturers have gone to hyperutectic pistons. They will work FINE with nitrous so long as your engine is tuned correctly. They don't like detonation, but neither does the rest of your engine.

Pete

Excaliber · #4 (**permalink**) 11-20-2003, 10:48 AM

,,,,they don't like detonation is THE reason I would not use them for a nitrous application. There are just to many variables in "dialing in" your nitrous shot early on in the game!

Ernie

blykins · #5 (**permalink**) 11-20-2003, 10:57 AM

I would take advantage of having it balanced before hand. I've heard from several different engine builders that Scat cranks are very hard to balance, and most of the time they require a whole lot of heavy metal. When I was having my Eagle stuff balanced, the machinst told me that he had to put $700 worth of heavy metal on one...Not very good news...However, I'm gonna have to go down that road myself, because Scat is the only company that I've found so far that makes aftermarket FE crankshafts...

By the way...I know that the hypereutectic pistons refer to the amount of additives in the metal. When you're looking at a phase diagram of a certain metal, there is a hypereutectic point. At this point, there is more of a certain additive than usual. For steel, hypereutectic refers to having more than .6% carbon. I suppose in aluminum (pistons) the hypereutectic refers to having more silicon.

I'm a Mechanical Engineer, and not a Chem or Metallurgical Engineer....so can someone share why the silicon would be a disadvantage when it comes to power adding?

I've always wondered about that...

blykins · #6 (**permalink**) 11-20-2003, 11:02 AM

I just re-read your post....were you asking about the "floating" rods? If so, that refers to the wrist-pin bore that the piston attaches to. A floating wrist pin is where the wrist pin has a significantly smaller OD than the bushing in the connecting rod. It is held in by clips on each side to keep it from moving. It's a lot less friction. A bushed connecting rod relies on a press fit for the wrist pin. Sometimes the wrist pin is just different by a few ten-thousandths of an inch.

If you did know that, just disregard my babble. :-)

One other thing...how much horsey-power are you planning on having? You might wanna step up to an H-Beam connecting rod instead of an I-Beam.

PSB · #7 (**permalink**) 11-20-2003, 11:14 AM

Quote:

Originally posted by blykins

I would take advantage of having it balanced before hand. I've heard from several different engine builders that Scat cranks are very hard to balance, and most of the time they require a whole lot of heavy metal. When I was having my Eagle stuff balanced, the machinst told me that he had to put $700 worth of heavy metal on one...Not very good news...However, I'm gonna have to go down that road myself, because Scat is the only company that I've found so far that makes aftermarket FE crankshafts...

By the way...I know that the hypereutectic pistons refer to the amount of additives in the metal. When you're looking at a phase diagram of a certain metal, there is a hypereutectic point. At this point, there is more of a certain additive than usual. For steel, hypereutectic refers to having more than .6% carbon. I suppose in aluminum (pistons) the hypereutectic refers to having more silicon.

I'm a Mechanical Engineer, and not a Chem or Metallurgical Engineer....so can someone share why the silicon would be a disadvantage when it comes to power adding?

I've always wondered about that...

I think this is a Ford vs Chevy type of thing, as I have heard the exact same thing about Eagle cranks. I (and my machinist) was very impressed with my Scat crank. It did not take much at all to balance.

Hypereutectic pistons are harder, and therefore more brittle, than forged pistons. A poorly tuned engine is more likely to detonate with a power adder. So, if you experience detonation, the hype pistons tend to crack and or disinegrate. But detonation is also likely to cuase damage to your head gaskets, heads, valves, ect.

Pete

Chris Dolt · #8 (**permalink**) 11-20-2003, 11:26 AM

I just bought a CHP 347 from TSS racing. It has the cast steel crank, forged I beam rods forged probe pistons, this is the 5.400 rod kit, all the rings bearings (I think most kits include this) for $899. Ask for Bryan. Coast advertizes this same kit for $999

Mike Sattelberg · #9 (**permalink**) 11-20-2003, 12:02 PM

Thanks for all the responses...

This was my first thread. I will check with TSS racing. I don't plan on using nitrous but I would like the hp to be around 400 (naturally asperated). I think that is an abtainable goal with a 347. I have used Hypereutectic pistons in other applications and have had good look with them.

I had a lead on a Scat cast steel 347 crank with only 3 hours on it. The previous owner put the wrong flywheel in a it took out the thrust bearing. I am not sure if it is worth having welded or just buy new.

tim88gt · #10 (**permalink**) 11-20-2003, 02:22 PM

I would spend the extra money and do it right the first time or you will end up doing it all over again. Defiantly get forged pistions it is well worth the few extra dollars, it will save you alot of money in the future if you ever do want to use nitrous. I would NOT use hypertectic pistons with nitrous no matter what anyone says. Check out CHP's stroker kits they sell quality stuff. I have a 12.1 347 on the way.

TCR_BRIAN · #11 (**permalink**) 11-20-2003, 02:30 PM

I've heard that Scat, Eagle, etc... have their cranks made offshore to their specs and then they are shipped here where the all final machining is done.....Hyper pistons work good in a N/A motor as they are usually lighter than a forged piston, less reciprocating mass....good for mild N20 usage 150 hp or less, but no where near as strong as a Forged piston....Hyper has all the benefits that PSB has listed....detonation kills, whether with a power adder or not....I would stick with forged having used both hyper and forged before, and a good quality one at that, such as JE/SRP or Diamond etc...and tell them what you are using them for...N/A (Lightweight), N20 Drop the Rings, ports etc....Stroking will shift your Powerband/ change compression/ etc etc.... make sure to spend the money where it really counts...HEADS!!!! 400 Hp out of a 347 is easy though....You could get it out of a 306, 302, 289 but like I said it will be higher in the RPM, thats all......so as example the 347 will make 400 @ 6000 lets say and the 306 @7000.....something like that........

tim88gt · #12 (**permalink**) 11-20-2003, 03:46 PM

by the way, what were you intending to do with this car? Daily driver or just a track car? Its important when you buy the kit you buy one specific with what you will be using the car for. If it is going to be a daily driver you might want to consider going with a 331 instead of a 347 this kit will last alot longer if driven often and the hp difference is not drastic loosing 16ci and in the long run it might be worth it.

machineman · #13 (**permalink**) 11-20-2003, 08:06 PM

Hi Mike I belive the 331 cid is much better also as for heavy metal it i not nessary. The balancing can be done exterally w/28or50oz. balancer&flywheel unless you want to pay for the extra expence. Also with the 347cid. you have to clearence the block for the rods. I have built a # of 331`s with the eagle kit with our cam& eldbrock peformer RPM heads,victor Jr. manifold&deamon carb. It makes 425HP any questions call 513-738-5001 ask for Eric;performance eng.

Ant · #14 (**permalink**) 11-20-2003, 08:48 PM

Considering going 347 myself, my engine builder has built a 331 stroker for a cobra owner that dynoed at 460fwbhp, with a dog manifold, but it was about 11.1 comp, and then the roller cam or a rocker s**t.

331/347 I can keep my weight down a bit, but the gas aint that good here to go much over 9.5.1 comp!
I have access to a Mexico block and have to contact him to get the numbers for a previous post of a knowledgeable US Cobra owner who knows what is the best block casting.
I gotta have at least 450bhp otherwise it aint going to do a lot on the track, I am used to big blocks with big horsepower, so thought I would try something different, just as an aside have seen a 383 Chev go in a four door Monaro, it had a turbo 350 etc, looked nothing, and it blew 600+Cobra etc into the weeds. Some people turn up in their nz$60K engines and they dont seem to have that real horsepower that many well put together simpler cheaper combinations.

Would it be better if you are getting over 430bhp to go for a Dart block?

My ramblings, and then the decision will be made and I will be stuck with it!

machineman · #15 (**permalink**) 11-20-2003, 09:14 PM

It depends if you are talk road or strip course. there are limits to how muct HP a 302 block can handle.If you want more HP go with 351w block be it ford or dart depending on budget. Remember there is no substute for cubic inches. Talk to your engine builder to build one for your aplication.

Mike Sattelberg · #16 (**permalink**) 11-21-2003, 05:41 AM

Ok, this is what I want out of this joy machine.

The Cobra will come from Factory Five Racing.

I would like to have a street car with the potential to run the drag strip. My goal is to be able to run on pump gas and run the 1/4 mile in the low 11s (or maybe in the 10s).

I have a 302 and a T-10 4-speed tranny.

I would like to build the motor before I purchase the Cobra. That way I can drop the motor in when the car is ready.

I am on a pretty tight budget so, I want the biggest bang for the buck.

blykins · #17 (**permalink**) 11-21-2003, 07:10 AM

I'd say if you could find a 351W block or a big block, you'd be better off, as you're gonna need at least 400 to get into the 11's. I have an old car and driver that tested an original 425hp 427FE Cobra...and with up to date street tires, it ran an 11.88 with a 4.10 rearend.

According to my FFR catalog, one of their 430hp 392ci Coupes ran an 11.90 with slicks...and their comp car ran a 10.99 with a 488 twin turbo 302...and slicks.

I'd say to get to your goal, you're gonna need at least 450 by my guesses...You could get there with a radical 302 or 302 stroker, but it's not gonna be very streetable in my opinion. You're gonna have to rev the pee out of it....or put twin turbos on it like FFR did.

If you're dead set on running low 11's, I'd say you'll have to look elsewhere for streetability and longevity. I bought a 1979 351w short block for $75. Of course I ditched all the internals and went with brand new stuff...but you can find them around. It's now 425ci, and makes a gob of horsepower and torque, and will be streetable. It makes all the power down low (5400 revs) and will idle at 900 rpm and 190 degrees all day long.

If you're dead set on drag racing, that's one thing. But if you're just shooting for low 11's on a street car, my advice is just take a ride in one...like I've posted in some other threads, it won't matter if it's 50hp and painted pink...you'll love it. I test drove a SPF car with a 430hp 392ci Ford crate engine...that thing would freakin scoot....what a kick in the pants. :-)

Excaliber · #18 (**permalink**) 11-21-2003, 07:39 AM

I DON'T want a Cobra that runs 11's in the 1/4 to be the SAME Cobra I drive on the street. I want to drive mine everyday, in and out of traffic. An 11 second car is a "nervous" car, take two aspirin before you hit rush hour traffic with that bad boy!

Ernie

TCR_BRIAN · #19 (**permalink**) 11-21-2003, 01:30 PM

Based on a 2200lb car, to run 11.0's you need 326.68 HP, so figure atleast 350-375, to compensate for factors that can't be accounted for, wheelspin, weather, but mostly a poor driver, etc etc....but mathematically are correct, and is what is needed minimum to run this time......These always help you plan accordingly.....

Brian

www.teamcracing.com