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Discussion Starter #1
what do you think of the 427 w stroker,351W block,DOOE-C,400M crank,340/360 dodge rods, KB 400 chevy pistons what is the RPM range on this combo. what HP can we get,WP heads 2.02/1.60 vavles Cam ??????????
does anyone run this combo now. give me your ideas in a 3500lb comet
 

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I think the lack of responses shows you that the 393 combo based on the Scat crank pretty much owns the 351W stroker market. Sure there are 377s, 408s, 416s and even a 422 they are the exception. I have one complete on the engine stand but it is waiting for the car.
You have probably determined that opinions vary widely on this board. The majority seem to favor the convenience and peace of mind a new crank and aftermarket rods provide. (Let's not get sidetracked and talk about forged or billet cranks and that stuff.) Focusing on the build you asked about, the incremental cost for the aftermarket crank and rods is small, but there are a few folks out there who prefer the other avenues.
I decided to build a 422 (4.140" stroke x 4.030" bore)while my brother concurrently built a 393. I wanted the extra cubes and wanted to kind of do it myself. I could have bought the package from PAW, but again, that wasn't for me. (By the way PAW offers a 420/426 with a 4.125" stroke and 4.030 or 4.060 bore. Speed-O-Motive offers similar packages.) The 422 was several times more work than a 393. The crank mods are substantial, the rod mods are too and there are all kinds of little things that will annoy along the way, like rod to piston dome underside interference and rod bolt to cam lobe interference.
On the RPM range, most seem to believe that you shouldn't rev the FMS 392 above 6k, so that same thought should apply to the 420+s too. They make lots of torque across the rev range, so you don't need to twist them. On the longevity of modified 340 rods, properly prepped and with top drawer hardware, they should be as strong as the Ford 300 6cyl rods which have lived well in 7k rpm boat 540s.
Two things are nearly impossible to change - opinions and habits. Whole bunches of folks read how reliable the 540 build was with the 6cyl rods, and many are unconvinced. Such is life.

On power question. Depends lots on cam and compression (doesn't it always?) but the fms 393 with a roller cam and gt40x heads made about 450hp and a bit more torque. With a bit more compression and AFR185 heads it made 520hp. In there somewhere.
 

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All I can say is my 'little' 418, (Eagle kit #14127), made 572.6 HP @ 6400 and 517 ft lbs TQ @ 5200 back in Feb. 2001. That was with a little victor jr. intake, and too small Dart sr heads.
Should be well over 650+ this year with better heads and much bigger headers!
And, FYI, I plan on winging this one past 7500 on a daily basis.
 

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Discussion Starter #4
R CODE thank you for your great reply

well what we are going to build is for race only. I see ford Motor sports is ofering a 392? with sportman block 351. for about 3900$$ what the rod and crank are don't know. Scat cranks have a bad rap for racing in the stroker kits. They are a soft crank and lose the menory and want to flex. I'am trying to find a good set up for racing and a lot of hard use and the four speed trys to push the crank out of the block. has any one built a stroker for race only and what is the down fall and the upside to it. the comet weighs allot 3500 lbs we can deal with that by rear gear ratio to get it out of the hole. any ideas on that
Alan
 

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Discussion Starter #5
Hey drag79stang tell me more the comet would love that on the weekends. it only comes out to play at the race track. It could feed on mice/rats and mopars for a snack. you can E-Mail if you like
Alan
 

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Just remember, you're dealing with "big block" cubic inches, and are feeding them through "small block" heads. The words of the day are, GO BIG!

It's hard to put too big of a head on a 400ci small block... especially an engine that is supposed to rev to 6k rpm or more.

Same goes for the intake manifold, headers, and exhaust system. GO BIG!


Good Luck!
 

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We be going big this year! Swapped the little 1 3/4" Mac long tubes for Hooker super comp 2". Got rid of the dart sr/s and Ed Curtis is building me some AFR 205's ported out to HUGE. Intake should be ok, (super victor), and carb should work, (Biggs prepared 950 HP).
Can't wait to get the heads, so we can toss 'em on the freshened short block and dyno the dude!
 

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Your original question was about the 400 crank-based 427 and I think they are fine for occasional strip use. When Richard Holdener dynoed the 392 he took it to 6500 but commented that wasn't where the thing should be run.
God bless 79 Drag Stang and his 4340 forged steel crank-based 418 with 12:1 compression. I love the fact that he is out there wringing that thing tight. The Eagle kit he mentions is $2100 for the reciprocating assembly and for race-only use is much more appropriate than the street-stroker combo you were considering.
 

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Discussion Starter #9
that's what I want to know is will it hold up to racing every week end for 6-8 mounths hard racing I think alot of you are running the strokers 90% street and 10% strip. we will run it 100% strip. we would like 13.00-13.5 comp. ratio with 110 oct race fuel and bang it with a 4 spd. and rpm it to it's limit or close to
Alan
 

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I totally disagree with the thinking of 392 Scat cast crank isn't strong enough. I know they can handle 7800RPMs and nitrous at the same time. I was building mine for nitrous and 13.5:1 compression and 7500RPMs and I've seen others do it with complete reliably. Does that mean the long monster stroke 4.5" Scat stroker crank shouldn't go past 6000RPM? NO! It can go 7000RPM safely and 7200RPM shifts if internally balanced and that's with a big heavy 4.5" stroke cast crank. Greg Cook wanted to get a billet crank and I talked him out of it. I even got Keith Craft Racing to back me up for him and they make over 1000HP at 7200RPMs with their cast Scat cranks and they also told me that 392 could more than handle what I had planned on doing. They said 7800RPM is the safe shift limit with internally balanced Scat cast 392 crank and also said my 13.5:1 compression and planned 350 horse shot of nitrous would be fine. They build and dyno race strokers all the time and they know the limits. Don't be afraid of non-forged cranks. The cast cranks are stronger than people here seem to give credit for. That's the same as that silly generalization that stock 351W blocks should only see 6500RPM max or the mains caps break or walk and 450HP is the limit. That is a crock too and people lately have finally realized that to be not true and that the 351W blocks can actually handle a lot of RPMs and HP reliably. Greg Cook was almost sucked into that trap too thinking he needed an SVO 460 block along with the billet 4.5" stroke crank but I convinced him otherwise and saved him a lot of money by using a stock '70 460 block block he had and the cast Scat 557 crank. He has accidentally taken his 557 to/past 7500RPM with nitrous and 13.5:1 compression (trying to steer to keep off the wall) and it's still alive. That 392 crank will live in that Comet for drag racing only taking it to 7800RPM shifts on nitrous with high compression. Just be sure to internally balance it and you'll be fine. Personally, if I had the money I would have gotten the 418 Eagle kit(cheap and 4.1" stroke) for even more power but the 392 was a much cheaper alternative since I already had the Eagle H-beam rods and 392 uses common 302 pistons which are cheap and have many different domes to choose from. Sorry, I didn't mean to bitch but those comments above about the Scat cast cranks shouldn't go over 6500RPMs really hit a nerve. I just wanted to set it straight though.
 

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Not trying to rain on anyone's parade here but there's a reason that forged cranks are in race cars and not cast. Cast cranks can be very strong but they are not comparable to good forged cranks period! I have never seen a cast crank in any purpose built race car in my life unless the guy had money problems and I HAVE seen all kinds of failures with large power adders and cast cranks as well as high rpm and cast cranks. The same with stock blocks.

There's a time and a place for stock blocks and cast cranks but 1000 hp high rpm engines isn't one of them. Are there great and beefy cast cranks that can take it for a while? YES! Would you do this on purpose or even if you had the money for better stuff? HELL NO!

Again the SCAT cast stuff is very good but don't think it's kryptonite or anything. The people that usually get into this mindset are drag racers since they put so little real time on their parts. Some of this crap wouldn't last 2 minutes into a circle track race and yet they think it's bullet proof!

Just be very careful when tuning your NOS stuff and you will be fairly safe. Of course the big block stuff can handle more hp than the Windsor but their's a limit to everything.
 

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I wasn't saying the Scat cast cranks are as strong as forged cranks but they are stronger than many people here seem to think. There are countless Scat cast cranks out there in race engines that are plenty strong enough to handle more power than most racers make. I know there is a point where aftermarket block and billet or forged crank is a better choice but for what radracing plans on is well within the limits of the Scat cast crank. Unfortunately with the big block, it's either Scat 4.5" cast or billet but no inbetween forged and Keith Craft Racing puts a lot of confidence in the cast 4.5 stroke crank and stock '68-'74 429/460 blocks for their own engine builds for customers who want reliability with high HP and he told me what the practical limits of the 3.85" stroke Cast crank and the 4.5" stroke cast crank and both were within what I was going to do and what Greg Cook is doing. According to KC, the real limiting factor on those Scat cast cranks are the RPMs and not the HP. 7800RPM with internal balance 3.85 stroke 392 cast crank and 7200RPMs with the 4.5" stroke 557 cast crank. That's while still being reliable and those are operating RPMs(max RPM safe shift points). If money is a factor, then Scat cast cranks are the way to go. If money isn't that tight, then forged. If a cast part is designed good enough for 7800RPM and you're only going to turn 7500RPM, why buy billet or Forged when cast will do the job. I would rather spend the money saved from using a Scat cast crank and put that much more in the heads, valvetrain, or induction where the power is. Since this is a drag car and only be seeing 7000+ RPMs 3 times for a total of a few seconds really doesn't place the stress on the crank like the circle track or road race type cars you mentioned. radracing is talking about quarter mile. A quick Zip ... shift ... Zip ... shift ... Zip ... shutdown. I do like the 418 Eagle stroker better for the added stroke and smaller rod journals but for drag racing, the smaller journals don't have enough time to build heat so that isn't really a consideration(well it is but not a big deal). I know Eagle forged cranks are stronger but Scat cast cranks aren't that far behind. Now CAT on the other hand...I don't trust.
 

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Flatlander Racing has 3.85,4.00,and 4.1 scat forged 4340 stroker 351w cranks for 529.00
The scat 3.85 and 4.00 cast steel cranks are 499.00.

I guess for 30 to 40 bucks I would build a nice "little" 421w using the 4.1 forged crank(4.04 bore)


the 392 can be built the cheapest using stock rods and off the shelf 302 pistons. But for a 3500# race car and race gas compression you should probably go with the better rods ,crank, pistons, and especially the cubic inches


A friend of mine just took apart a 500 HP(508 on dyno) 7200 rpm 351W that was using a 71 block and crank....he did find a crack in the crank...but that was after 300 passes
 

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Discussion Starter #15
I think the 418W is the way to go for me, I need ci to get my lead sled out of the whole
3550 lb.brick

Ok the 418 is good for 7800rpm ??????.I like rpm and it lets my 2.02 valves and heads flow to there peak hp
what is the differance between int & ext bal on the strokers does it give more rpm. can you use the same SFI balancer

I can buy the 418 w kit for 1900 $ with best steel crank good rods,and pistons
Alan
 

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Kent,

"" I wasn't saying the Scat cast cranks are as strong as forged cranks but they are stronger than many people here seem to think.""

This is definitely true. If you have the motor built and tuned right everythings going to last longer and be more reliable. The SCAT stuff is good for it's price point.
 

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Chilly..........I just got off the phone with MSD, and finished ordering my 11 grand chip........


In all seriousness, whatever the dyno shows the 418's makin' power to, is where she'll go to. Only behind the seat (ass dyno), will see where the HP/TQ falls off. I do not fear in any shape/form/manner taking a small block, (even one of epic 418 proportions)
way past 7500. Again, it isn't like it's THERE all day long. Just a dozen or more times every weekend, (and when I fire it up in the garage to piss off the neighbors!!
(good one Chris)
 

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From Eagle, it only costs $275 extra to have it internally balanced. (at least that's what mine cost back then).........



and it feels so smooth /vibration free @ 11 grand
 

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Discussion Starter #19
romer has it that scatt makes 2 differant cast crank and one steel crank??????????????
and people go for the low cost scatt and it does alot of flexing??????????? this is what I've heard at the track last summer any shed any light on this or is it just BS.
Alan
 

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Discussion Starter #20
that's what I was trying to find out you hear so many stories about it. I think If there no built right they blow up. my 2 cents
Alan
 
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