557 Dyno Results

How does 784 Horsepower at 6,400 rpm and 731 lb.ft. of torque sound.557,10:5.1 Compression,Victor Intake,Quick Fuel QFX 4700 1050 Carb,Aluminum Super Cobra Jet Heads 419 cfm Intake at .800 lift and 266 cfm exhaust at .800 lift,Hooker 6224 Headers 2" primary and 3 1/2" collector.

Thanks Mark.

I dunno....sounds a little weak to me

Sounds pretty good! Any specific reason for the 10.5 compression ratio?

Charlie

Charlie,

This was a build in the Fastest Streetcar Magazine,they plan on driving the car on the street.I imagine that's why they went with the lower compression.They put a Nitrous kit with a 350 horsepower shot and ended up making 1,242 horspower and 1,208 lb.ft.of torque.They used VP Q16 fuel for the nitrous dyno pulls.

Later Mark.

Mark,That sounds pretty good to me.I have a 552 with P-51 Charlie heads and ported intake by Charlie.My motor is 10.0 with small 726 lift Lem cam in it.When Lem and Jet Boat Bob set this motor up for me ,I also wanted to be able to drive on the street and to cruise ins,plus beat the hell out of it on the track.They came up with this combo which neted 744 hp and 712 ft of tq.I run a new 1150 hp.Yes with a bigger cam,and 14.1 I would have ended up with about 895but I really want to be able to drive and enjoy this on the street.Oh ,and I'm set up for a fogger system also.Michael

The guys who dyno tested the engine said they didn't think it would make 800 horsepower with the compression they were using.They did say with a tunnel ran and another carb they could have made 800 horsepower or more on motor.

Later Mark.

The only existing cast tunnel rams for the CobraJet or OEM style heads are 40 year old Offys and Weiands. Neither of them in stock or fully ported form, are any better than the ported Victor or unported TFS Street Mafia intake manifolds with single Dommy carb. I've done a good bit of dyno testing with Blake C. last year and with Dave F. two years ago in that regards.

It is going to take a welded and highly modified Weiand 2 X 4, with maximum porting, epoxy and flow testing to order to possibly beat the single plane TFS Street Mafia or fully ported Victor single carb manifolds. Much more money than the average racer would want to throw at them. On big problem with the tunnel rams, is that the runner taper is all wrong.

In regards to that 10.5:1 magazine engine that was dyno tested, IMO the biggest and best change would come from giving it some more compression.

Charlie

10.5 would certainly be a conservative compression ratio with a roller cam. However, if nitrous was intended to be used regularly, maybe 10.5 is not all that low.

Not sure how a nitrous assisted 557 would hook up on the street

Would a 12.5-13.25:1 CR be better on this engine?

I hear the bigger the bore and the longer the stroke the easier it is to get a higher CR( a 557 has a +.080 overbore and a 4.5 stroke right?)?

Don't know OP doesn't say but I figure Street/Strip.

Street/Strip is what I want but am too $hort right now.

the OP doesnt own the engine . those specs are from a magazine he read

DanH is correct this isn't my engine it's in the May 2011 Fastest Street Car magazine.It's actually bigger then a magazine,it's like Race Pages that NMRA publishes.

Later Mark.

Not worth a shit Mark without cam spec's LoL Just Kidding, Great Info.

I was looking around a the Weiand Stealth 8021 intake Dyno Numbers and this popped up.

its only 11 years old!

That's true. We seem to almost be back to SCJ heads with the parts shortage. Also Dominator intakes seem to be scarce. I was looking at the Stealth Domi Dyno combo and I saw Mark's thread pop up first on my search on my Google search and they even had 2021 next to it for some reason. Yes I did see it was 2011, so.

Thought it was pretty cool they made that kind of HP with so little compression.

I also bumped Blakes question on the Stealth/Domi deal he said he could not beat with his stock Victor on the smaller engines back then.


https://www.429-460.com/t2627p25-bbf-intake-shootout


Anyway some of the new guys might enjoy it, or want the info and I did not think the old tread police cared.

Here's another 557 low compression Nitrous build.

TFS 325's, Mafia Intake Unknown Roller Grind, 102N pill 95F pill. 93 octane. 754HP Motor 1080HP Spray.


https://www.youtube.com/watch?v=gvYI6RQpaWc

If you saw it great, if you didn't enjoy.