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Author Topic:   parts selection Q
mod4
Member
posted June 15, 2003 01:34 PM
I'm a fella who has been racing modifieds for the past 10 years, and moved into 360 SprintCars this season.
After 5 races, I'm happy with my progression as a driver, but I'm scared to turn my motor past 7200, which is a problem.
I'm (not kidding) currently running a 59lb crank, way heavy rods and pistons (all "Trick Flow" stuff, from a limited late model motor that was laying around).
Yes, I have been told they are Chinese junk. I lay awake nights worrying.

Yes, really.

My question is, I am ready to build a motor. It has to be a 360". It will probably be a Dart block, altho a Bowtie "Sportman" block is possible to, I have to find out the bare weights - my SprintCar needs a weight reduction and every little bit helps. I don't have the budget to lighten a block.

I would like input. I am running the ASCS "Spec" heads from AFR, so I think by 8200 they are done flowing. I have Jesel shaft rockers, so I feel safe there. My cams come from Crane, they are great about providing what we ask for.

I need information about cranks, pistons and rods. The only "racing" crank I have bought in my life is a Dragonslayer for the Modified, and that was from Mr Hendrens' advice.
I need a lightweight rotating assembly I can properly assemble, turn hard, and still sleep at night.
Brands? Combinations? Odd tidbits?

Thanks everyone in advance.

rocket36
Member
posted June 15, 2003 02:09 PM
most of the guys in australia that i have seen running 360 cars seam to run Scat, Lunati, eagle or cola 4340 cranks. and they seem to be fine. the same brand rods also seem to be common. with JE or ross pistons.
most of the cranks aren't super lights or anything real fancy, usually just knife edged and undercut counterweights. if your allowed, a good dry sump is definitely worthwhile.
from what i have seen though, the most imortant thing is to make sure your tune up is spot on, and that assembly is thorough and careful and your machine shop does a good job with all clearances and finishes and balance is accurate.
very rarely do you see a broken crank through over reving, normally due to another problem like detonation or oiling or most common in sprintcars is breaking off the flange at the back due to the shock loading while push starting.
good luck (poor choice of words i suppose)


sdhnc29
Member
posted June 15, 2003 03:31 PM
The Dart block is an excellent choice , though I'm not sure how it compares in weight to the other block's that you mentioned . As for crank's , you could step up to a lighter weight Callies , or comparable American made crank shaft (small journal / 350 main ), and cut at least 10-12 pounds off the 59lb crank that your running now . You will also be looking at spending at least $1,400-$1,500 by doing this . As for rod's , I would look seriously at buying a set of used Carillo piston guided small journal rod's (around 610-615 gram's ). JR Motorsports sells these rod's quite a bit , and at a good affordable price . For piston's I would go with JE or CP . Both of these brand's will cost a little more than other's , but they both are the best you can buy in my opinion .

If you want to save a few dollars , then I would stick with 3.480"-3.500" stroke , 6" rod combo . If you do this , then shelf stock piston's are readily available in any brand that you choose , and will eliminate the need for custom made piston's . these crank strokes are also commonly stocked by most every major American crank manufacturer , so there is no extra expense for having a different stoke crank made , and no 6 week waiting period for the crank to be produced .

All together , you should not have more than $4,800 invested in part's that will give you a virtual bullet proof short block . Once you factor in machine work to finish a Dart block , balancing , resizing used Carillo's , re-bushing used Carillo's , ring's , bearing's , etc. , etc, you are probably looking at around $6,000-$6,200 for your total investment , if you can assemble your own engine . You should also see a rotating weight reduction of 10-15 pound's depending on the part's used , based on the your description of your current part's .

If you use a combo like this , it will be very reliable , and like I said earlier it will almost be bullet proof , as far as part's breaking. Of course there is much more to be gained by pushing the envelope on crank weight , rod weight , piston weight , crank stroke , rod length , etc. But this will add much more to the cost of this engine , and will ultimately push the envelope of reliability . Once you master your 360 sprint , and decide that you need more , like we all eventually do , then perhaps your budget will allow a further upgrade . But for now I'd stick with what I have described , and sleep easy .

Steve

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


66jj
Member
posted June 15, 2003 08:34 PM
dart block added almost 30 lbs over a stock block. i believe a new bowtie is lighter.

scat makes a lw 43 lb crank for 1000

jr motorsports has 32-36 lb cranks often also.

another option how about a mopar craftsman truck engine ready to freshen last i heard 7500 most with dry sump pumps etc on them...

Jeff Joldersma

stockcar5
Member
posted June 15, 2003 10:17 PM
i'd stay away from the scat cranks in a motor like this. doesnt matter what kind of price they put on it..still china junk.

luke

rocket36
Member
posted June 19, 2003 01:44 AM
doesn't really matter if they come from china, it is only raw forgings. Scat have set tolerances that they will accept, if they don't come up to standard then they are not used by scat.
Scat finish all there cranks in the us unless you choose to by an unfinished item.
Scat also supply raw forgings to most of the other major crankshaft brands so there is a good chance you are still buying one anyway, regardless of the brand name on the box.
Scat also have made a huge living from crankshaft supply, do you really think that they would risk everything by supplying inferior products.
The reason they are made in china is because the labour is so cheap, that means that you can buy a crank cheaper.
Do you wear nike, reebok shoes??? whereare they made?
We run a Scat crank and rods and have never ever had a problem... if you have, chances are something else has gone wrong in your engine that has caused the scat product to fail.


sdhnc29
Member
posted June 19, 2003 07:14 AM
Please click on the attachment to see Chinese quality . And no most American crank manufacturer's do not buy raw forgings from Scat . And I have to buy new Reeboks every 3 or 4 month's , they keep falling apart ........LOL

Steve

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


outlawstock17
Member
posted June 19, 2003 07:42 AM
yikes! that looks like a ford crank!

i can't speak for anyone else, but i've had good luck with "chinese junk". i ain't tryin' to twist them to 8500 rpm's though...

hey steve, you don't have to buy reeboks....i get my "tennies" from walmart.....the same 11 yr. old kid in an indonesian sweat shop sewed them up along with your reeboks....lol.

rocket36
Member
posted June 20, 2003 04:31 AM
nice photo. my guess is that there are probably photos of american made cranks that have broken around the place, even the best can fail. out of interest did you find out what caused this failure, or was it just because it was made in china. now i'm not trying to be sarcastic. but i would be interested to know your findings as I have only seen a hand full of broken cranks.
I have heard of cranks failing because of poor handling (ie dropped or knocked when being freighted), they have been fractured, but i haven't seen it, is this possible?


KSGerry
Member
posted June 20, 2003 05:19 AM
"...I would like input. I am running the ASCS "Spec" heads from AFR, so I think by 8200 they are done flowing..."

Are you required to run ASCS "spec" heads? Personally, I would change to another brand if not required to use them. Also, I notice that you mention 8200 rpm. I don't think you have to push your engine that hard unless you have deep pockets to replace rpm fatigued components and race with the throttle wide open all of the time on a big track...half mile or bigger.

Our sprint engine builder suggests keeping the power band mid to high range and use 7500 as the upper rpm limit. Use a combination of components...stong, but not necessarily the lightest weight, American-made rotating assemby and valve train with the proper cam and a head that flows best in that range. Go for torque instead of horsepower.

Do you have a weight limit for the car? You may want to change out your driveline to lighter weight components from the crankshaft coupler to the rear wheels. Don't forget to examine any component on the car that adds to unsprung weight...shock absorbers, Jacobs ladder, torsion bars, arms and stops, bird cages, front axle, king pins, hubs, etc and try to find a lighter alternatives.

Just my thoughts...
Regards,
Gerry Dedonis
4+ NCRA 360 Sprint

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KSGerry

[This message has been edited by KSGerry (edited June 20, 2003).]

mod4
Member
posted June 20, 2003 10:15 AM
Yep, those heads are required.

Thanks everyone for the input!

Eljojo
Member
posted June 20, 2003 09:05 PM
Hey Steve, has Bill got the crank welded back together yet? LMBO!


sdhnc29
Member
posted June 21, 2003 12:02 AM

rocket36 ,

I should give a little background on this crank . This was not an engine that I built , but one that I had done machine work on . This customer originally came to me and wanted a complete 347 stroker engine for his drag car , Mustang . I tried my best to convince him to use a Callies crank , or to buy the equivalent American made crank of his choice (not including BRC which I rate about like a China crank after Tennessee Engine Works sold the original BRC crank division) . Anyway .....he went against my advise and bought this Eagle crank in the photo (I should say that this was the third crank that he brought to me . The previous 2 had some serious quality control problems ...i.e. tapered journals and oversized ) I went ahead and did the machine work for him (this was all his own combo ), balanced the rotating assembly , etc. I then told him that I would not assemble his engine , and he would be running this crank over one day ..LOL He ended up getting his engine together , and brought his car to my business to run on our chassis dyno . After everything was tuned for him , he left and I did not see him for about a year or so . Then on a Saturday , he pulled up in his truck and asked me to have a look at his engine . When I walked outside , I found a once awesome SVO block sawed in half , and the pictured crank . My first thought was actually that he broke the main web's , and caused the crank to break (this is quite common to see when you find a broken or severely cracked crank). But after magging the block , I found no crack's in any of the unbroken main webbing , and there was no evidence of the broken pieces moving around like they had been broken before the crank broke . I then took the crank pieces into my wet mag , and every single journal that was still intact was cracked . After inspecting the rod bearing's and the piston's , I could find no sign's of detonation . I was lead to the conclusion that this crank was simply made from poor material , had internal production flaw's , or a combination of the two . The kicker to this whole deal is that this was a naturally aspirated single 4bbl engine that never saw NOS or any type of performance enhancing fuel . This guy was a simple bracket racer who lost a crank , 8 Crower rod's (yes he actually used good rod's ...LOL), 6 pistons , a SVO block , oil pan , one TFS head , roller cam , several lifters , valves , and the input shaft on his tranny . All because he saved a few dollars making a bad choice on the crank he used .

Eljojo ,

LMAO !!! Did you ever see Fast Times at Ridgemont High ??? Remember this ..." My old man's got an awesome set of tools" Unfortunately not awesome enough . LMAO

Steve

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


rocket36
Member
posted June 21, 2003 05:23 AM
interesting reading.
I respect your loyalty to home grown brands. It is good to see (keeps people employed).
I guess you've seen a bad result and will consequently try to do everything that you can to never experience the same thing, as most of us would.
By the same token I have seen a friends drag car (348cui, 8.5sec 1/4mile) run a factory GM cast crank for years & never have a failure.
I have visited the SCAT factory and it is an awesome facility. i'm not saying they're the best, just an alternative.
I believe scat supply ford & chrysler with products as well as nissan & toyota, winston cup and world of outlaw teams (check their web site).
I guess it boils down to using what you believe in, but regardless of where a component comes from or how much it costs I'm sure you'll agree that an extremely close inspection (sometimes crack testing) of all components is required before assembly.


Eljojo
Member
posted June 21, 2003 07:25 AM
I like the new ad for Callies where the ol' lady is asking "How much did you save on the import crank?"


sdhnc29
Member
posted June 21, 2003 08:31 AM
Yes I believe the GM cast crank is a better choice than the GM steel crank . Even in short track circle track engines that must run an average of 7-15 miles every night . As for Scat cranks being in Winston Cup engines ............ not in any one that I've ever seen , or used by any team that I know . Most commonly you will find Bryant , LA Enterprise , Weinberg , Callies , Crower , and some King cranks . I'm sure that Scat is advertising on Cup car's , but this is most likely simple monetary donations . The same goes for WO sprint car's/engine builders . I can't speak about any of the OEM work that they do , but this is usually subbed out to the lowest bidder . I know that Cola is now doing a lot of OEM work as well . The foreign stuff is believable since Scat made there reputation building VW's and VW part's originally .

As I'm sure that your aware , any race engine has all part's magnifluxed and each engine part documented before it's used and during it's life cycle .

Your also correct in assuming that I will not use any Chinese part's in any engine that I build and must stand behind with my reputation .

Steve

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


dgb
Member
posted June 23, 2003 10:12 AM
ford is putting their reputation behind scat cranks. a new shortblock from ford will most likely have a scat crank in it.....and man are they hard. my crank balancing machinist drilled in my flywheel instead! arrrg!

i miced all the journals on my scat crank and they were right on. i did have to use a half a set of .001 oversize bearings to get the rod clearance i wanted though.

i'd like to have a nice american made high dollar forged crank, but i can buy 5 scat cranks for less. $180 bucks shipped to the door for a new ford 351w crank. if i had to buy only american parts, i'd have to run a cruiser!



sdhnc29
Member
posted June 23, 2003 10:52 PM
dgb ,

Yes in pretty much every circle track application that must use a stock crank , I prefer the cast GM crank to the steel one . This opinion is based on what I've seen over the year's , cast vs. steel breaking and cracking . The cast cranks are not necessarily tougher than the steel crank , but in my opinion they handle high impact loads much better before cracking or breaking .

As for rating the GM steel crank vs. the Chinese stuff ......... I really would never use either crank unless it was mandated by a rule book . With the introduction of the Callies Dragon Slayer crank that can be purchased for around $749-$789 depending on main journal , rod journal and stroke ..... there is just no reason to buy a GM steel crank over the counter anymore . If your on a budget , and want a great crank for your money , then I'd buy the Dragon Slayer . It's the same crank as the Magnum , Magnum Plus , and Magnum Plus XS ......... but without the weight taken out and the extra counter weight profiling .

Your putting me on the spot here by making me choose between the Chinese cranks and the GM crank .....LOL So .............. I better not give my opinion on that in fear of lighting up this message board ...LOL PM me and I'll be glad to give you my run down of what cranks I'd use before I ever used a crank from China .

Steve

------------------
Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


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