Confuzed1

iTrader: (4)

Well, just called about my engine (the 400), and the dyno is done and ready for pick up!!

BUT - I was expecting a little more HP from it, but I definately have no complaints on the torque it made..... 390 HP and 490 ft. lbs. torque!!

I was hoping to get a little more HP from it (at least 50 more), but in all fairness, I did build it for 0-6000 RPM torque.

What do you think?? I don't know any specifics as to what RPM etc. because I don't have the dyno sheet yet. Can't wait to see what it'll do in the car!!

dj haf

sounds awesome dude! that car is torque CRAZY... just make sure you have the means of getting ALL of it to the street and you'll be set but yeah, i'd expect a little more hp from a 400

EDIT: i take it those numbers are crank hp, and not rwhp, correct?

Ray87Z

That seems to be down around 50-60 hp from engine dynos I've read about for the nearly exact same setup on a 400. Lotta torque but how much can you really use... Hmm. What kind of headers was it dynoed with, regular full length dyno headers?

CHP mag did a nearly identical build actually that I happened to save, same heads (w/ 9.5:1 compression on their 406) and same XE274 cam, with a Performer RPM inakte being the only difference that sticks out (your "Crosswind" is basically a copy of the RPM Airgap though isn't it?) and got 452hp @5300rpm and 509 ft-lbs @4000rpm. That was with 1 3/4" headers with no mufflers, only accessory on the engine being the water pump. For a professionally built 400 that I dropped alot of coin on I certainly would have been expecting more, but perhaps that is unrealistic... Perhaps the shop that dynoed yours used shorty headers and had other accessories on the engine and the power numbers reflect more realistically what it will put out in car, etc?? I doubt it but ask what the dyno setup was...

Aren't you the guy that the shop wiped out a cam lobe or something first trying to dyno it? I'm wondering if you didn't get hosed along the way somehow...

five7kid

iTrader: (14)

I would expect more, too.

You might be a little low on induction. Assuming 100% VE, you should have at least 710 CFM @ 6000 RPM. Common practice is to increase carb size about 10% above "formula".

I'm not very familiar with the Crosswind products. They "look" like performer style, you'd probably be better off with an RPM or Stealth type of dual plane.

Blackroc86

I was also going to mention the carb might be a touch small for that setup.

AJ_92RS

As RB would say, try something other than the chineseium intake manifold.

Confuzed1

iTrader: (4)

Thanks for the input!!...now you guys have me a bit concerned. But that's why I posted the actual results....so there's something holding it back??

I've seen the dyno they use up close, and I know the water pump is engine driven, and straight dyno headers were used. I also specified I wanted to dyno on pump gas.

Yes, the "Crosswind" intake is a copy of an RPM air gap. I had it port matched, and I also paid to have additional porting done on the heads. And, you're right again - I was the guy that had 2 cam lobes wipe on initial break-in.

I'm with ya on the HP thing. I expected more HP and perhaps a little less torque, which is why I posted this. The only thing I can think of that "may" (not sure) drop the HP figures is the use of 1.6 ratio rockers on the intake side, and the use of 1.5's on the exhaust. Would this cause a bump up in TQ and lower HP??? Still not complaining though! - Or should I???

So far as the carb selection went - both the builder and a tech rep from Demon talked me out of going with a 750 cfm carb after I described my setup. And money wasn't the object because both the 650 and the 750 Speed Demons were the same price!! They both said the 650 would be the right choice, and was plenty adaquate for the setup, and the selection chart on Demon's website seems to point to a 650 cfm also....

And AJ92 - "Chineseum???" - Could you please clarify? I doubt RB would say that in this case, because he helped me out with this entire setup!!

Sitting Bull

Every dyno is different, some significantly so. That will doubtless explain more than a little of your hp comparisons.

Once the engine is broken in, it should develop a bit more power, too.

I think the 650 is probably OK, as well. At least according to the 2nd latest CHP mag. 390 hp is a lot and just getting that power to the ground will make your 3rd gen a rocket!

AJ_92RS

Made in China.

I never said he will say it.

I said "as RB would say"..... as in using his terminology.

I'll give you my terminology so maybe you'll better understand.

You get what you pay for.

RB83L69

Me??? say THAT????? in public even?!?!? you gotta be kidding!

Seriously, I would have expected more HP and torque both. I'd have been looking for around 425/525 out of that combo on an engine stand. Tuning could be one thing holding it back, if they didn't work on the carb or the timing very much.

Post the entire graph vs RPM and fuel mixture if you have it. Often the shape of the torque curve contains clues as to why the engine does whatever it does. In particular, just the peak numbers by themselves don't necessarily tell how fast it will go; if it does, say 490 ft-lbs peak but is above 470 all the way from 3000 to 6000, it may very well out-pull a motor that does 525 peak but is down to 425 at 3000 and has a "Mount Everest" torque curve.

Confuzed1

iTrader: (4)

Ok AJ92.....whatever. I got what I paid for. I suppose if I had gotten an Edelbrock, my HP would go up. I also have a proform distributor....so feel free to call that chinese or whatever.

Not sure what I did to warrant that response from you, but if you were honestly answering the original question I posted, and you think my intake is keeping HP numbers down, then so be it.....

And thanks for all the other replies so far.

EDIT: RB, you were writing the same time I was!!

Yeah, I was expecting a little more HP out of the engine. I got this info over the phone by a girl who works there- but I'm assuming it's the peak HP and TQ she was looking at.

Air_Adam

650cfm carb? That seems a little small... I think a 750 or even a 800 cfm might suit that engine alot better.

F-BIRD'88

Did they try a750cfm carb? A regular Holley 750 or a
"lowly Edelbrock"? need to see tthe dyno sheets as
RB mentioned ( fuel curve etc) The water pump eats about 15-20hp at 6000rpm.
I also would expect more power out of that combo.
Need to know the dyno setup (acceleration rate etc)
makes a big difference.

A 750 carb is typically good for 10-15 peak hp over a 650.

kd5boc

You could also adjust your cam timing to bring the torque closer to where it would be more useful...that should give your engine a little more hp on top...

would like to see the rpm's to help with that.

Riley's35089rs+

I havent seen it yet but the builder of my motor claims 525hp with this set up. DD2000 shows about the same...I.ll be in the real world real soon,,,just waiting for some help,,,

SSC

Nope thier wrong. I'd not put anything less then a 750 carb on it, more like 800 as mentioned.

Have the builder if they did what I'm reading take the 1.6's off the intake side and have them swap the exhuast and intake rockers, 1.6 exh 1.5 int. I bet just doing that will bump the hp up a few notches.

Confuzed1

iTrader: (4)

Well, SSC - This is just frustrating to say the very least!!! Who am I supposed to listen to??? Huh??

I get good advice from people like you on the board, and I was really listening.....then I get this thing built and BOTH the builder and a rep from Demon talked me out of a 750 cfm carb!!!

But both agreed that a 650cfm Speed Demon was the way to go, and both cited something about how Demon rates cfm differently than Holley does.

I also remember telling both of them that I had never heard of running such a small carb on a 400, and BOTH said, "if you were running a Holley, then yes - you'd need a 750".

I'll double check on the rocker configuration. But I'm pretty sure it was 1.6's on the intake and 1.5 on the exhaust side....

I DO intend to talk with them tomorrow, and ask him about the low HP, and how I'm a bit dissappointed with it and see what he says. I do recall on several occasions that I was hoping for close to 400 HP - at the rear wheels.

But - as RB83L69 was saying, the "peak" HP and TQ may not be the full story.

AJ_92RS

That could be part of it. That's why I'm saying it.

The other part can be the carb, but I can't see that happening. I've read of many 450 HP engines with 650 carbs. Not saying it doesn't need to be tuned though. It could be that simple.

The other thing is (as RB suggested) the combo. That could be a "tree stump pulling" combo you have there. We'll know more with a graph.

IMHO, an XE274 is not a high RPM cam in a 406. My friend has that cam in his 355 in a '69 Camaro, and it's barely aggressive in that engine. It's only .490" lift. Those Dart heads would seem to need a lot more than that. But that's just my thoughts on it.

Honeslty, you have no reason to be upset. Those are still good numbers, it's just what happens and when that's surprising, right?

Did they advance that cam at all?

Confuzed1

iTrader: (4)

Allright AJ - maybe I just took what you were saying the wrong way. It's cool. I guess I'm a little frustrated with the HP number.

My original plan was to use a RPM Air-Gap intake, and the builder said the "Crosswind" was the same thing, same quality. He sells both. My intention was to also go with a bigger cam, (XE286H?)
but the rep from Comp cams talked me down to a XE274H since I'm running power brakes and plan to drive it 90% on the street...

So far as I know, they installed the cam straight up.

From day one, my intentions with this build was a "streetable" engine running in an RPM range of Idle-6000 with plenty of torque. Well - the Tq is there, just wish the HP was a bit better.

Maybe you're right -it's just a matter of tuning. But I was kinda hoping to get most of that out of the way on the dyno!! I figure I'll have to adjust the idle and maybe set the timing back a little after it's in the car, but that's it.

After all, I figure a dyno is the ideal situation for some good initial tuning. But since I don't run open headers and have accessories etc, I'll neet to adjust timing a little.

Riley's35089rs+

Sounds like you have done what you have sat out to do.....A "streetable" 450-500hp smallblock isn't that easy to do.
Mine will hardly be "streetable" only acc. is the alt. no power steering..no ac no heat..electric waterpump. With over .600 lift on a roller cam professionally ported Dart/Sportsman 2's. Mechanical secondaries on a 800 Holley/Contender.
I think I will be driving the 94 to the store . Light to light..you are gonna kick some a$$.

Confuzed1

iTrader: (4)

Thanks for the vote of confidence Riley's35089rs+!!

I spoke with the builder today, and politely questioned the HP issue, and I told him I thought I'd get just a bit more out of it.

He pointed out a few things, one of them along the lines of what Sitting Bull was saying about the dyno being a bit conservative. He says he's built simular engines that his competition has dynoed higher, yet he's beaten them at the track.

Also he said he could get maybe 20 more HP out of it by leaning out the secondaries a bit, but I wouldn't want to run it at the track like that.

Also he took off the 1.6 ratio rockers all together, and I now have 1.5 RR all around now. He felt that the 1.6's were causing some coil bind problems. I'm not going to argue that one since the first cam was wiped out using 1.6's....

So, I asked him about the HP/TQ curves and he said it "pulls like a big block" and the torque curve is pretty flat.

So I guess I can't complain too much - He's been straight forward with me from the git-go, and I'm happy about that.

He also added that if I really want more HP, I should get rid of the "short" cam and change it for a solid roller. He also explained a lot of other stuff, but basically he built pretty much what I asked for.

So.......I plan to pick up the engine in a couple of weeks (stupid work schedule), and I'll post up the dyno sheets then.

Thanks for the replies everyone!!

five7kid

iTrader: (14)

Sounds like the Stang hunting season is about to begin...

Riley's35089rs+

oh yeah..

Confuzed1

iTrader: (4)

I picked up the engine the other day (3 1/2 hour drive), and the S-10 had no probs hauling it, but I took it easy on the entrance/exit ramps on the highway! lol Anyways it's on a stand now.

I don't have a "graph" per say from the dyno, just a line by line printout of what the TQ/HP RPM's,Water temp,Oil press, Barom. Hg., Rel Hum. % and finally what exhaust temps were during the run. Sorry, but I don't have a scanner.

The RPM range was set from 3000 RPM's to 5500 RPM's. I kinda wanted to see like 2000 up, but oh well.

HP peaks at at 4600 RPMs and TQ peaks at 3400 RPMs. What's interesting is even at 3000 I still have 444 on TQ, and HP at 253. And TQ doesn't drop off 460 ft lbs till around 4600!!! I have pics of the engine, but too big to post here I guess.

Only thing I've heard so far as exhaust temps, is that you don't want to see any above 1400 degrees. #6 cylinder came close at 1398 degrees at 5500 rpms.

Now I need to get a bunch of nickle and dime stuff to get the engine in, like throttle brackets etc...uh - rearend, better clutch.....

dj haf

you better tell us how she runs when you drop the motor in... im betting you're gonna soil yourself on your first WOT run with all that torque, lmfao j/k

Damon

Remember that carb recommendations can also be affected by the type of intake. Old school wisdom is that a dual plane intake wants a LARGER carb than a single plane intake. How's that?

Well, on a dual plane intake any given cylinder only "sees" HALF of the carb. On a single plane it sees all 4 bores.

In my experience, I have found this to still have a lot of validity today.

With a single plane intake you would probably be OK with a 650.

On a dual-plane, no way. 750 MINIMUM. 800-850 preferred, going from personal experience. There's a reason that GM put high flowing 4bbls on even mild 305s and 350s with dual plane intakes. This is why.

The good news is that you can upgrade later. It's not critical, but you have something to look forward to in the future.

Confuzed1

iTrader: (4)

Damon - Have'nt heard you on the board in awhile! I know what you're getting at so far as carb size. The 650 they put on is jetted up. They are running it with 79-80 size jets, up from the 71-72 size that came with it new.

I explained my setup in detail to the tech rep at Demon, and told him the intake/cam combo I'm running - and still a 650 was recommended. I may change up to a 750 Holley later just to experiment.

And dj haf, I'll most likely be happy with the power (and sh*t a brick) lol - until I snap the rearend........then the fun will be over - till I get the Moser I've been eyeballin!

Riley's35089rs+

just run the stock driveshaft ...cheaper to replace!!

TA

iTrader: (1)

Confuzed:

Since you originally specified that you were going for a primarily street driven combo, I think you are way in the hunt with those numbers. Don't get lost in racing HP numbers, the torque will very capably accellerate your car. If you were reaching for max HP (like magazine guys usually to do sell magazines) you would build the combo differently. It has been mentioned here that just changing cam timing, running longer, larger diameter headers and a bigger carb will bring your HP numbers up. It will also raise your torque peak RPM, and probably decrease your gas mileage. Bigger cam, solid roller, 800 CFM is not what I would consider smart for a vehicle regularly street driven.

With 490 ft/lbs of torque, you should be spending your time and energy trying to get it to the ground without braking anything!

It's gonna go ballistic when you hit the loud pedal. My crystal ball predicts you will be forever in search of rear tires...''

Troy
So Cal

va454ss

iTrader: (1)

I have to jump on the bandwagon and say get the 750 carb.

You may give up a tad of torque on the bottom end, but doubtful.

You'll gain a bunch up top.

And it is true, you need a bigger carb with a dual plane vs single plane as explained earlier.

Plan on using drag radials everyday

Confuzed1

iTrader: (4)

Well va454ss, there's really not a bandwagon to jump on here. As I've said earlier, both the guy that built this AND Demon themselves talked me down to this 650, Money wasn't the issue. Both were the exact same price.

If you can't trust the people that make the carb, then who?? I'd never heard of it either, I figured 750 at least like everyone else here.

And I'm not taking anything from experienced guys here either when I said that. But I'll be upset if I find that a 750 cfm makes a big diff. like I'm continuing to hear......- jury's still out.

Oh yeah - Thanx TA, yeah you're right, a solid roller is a little radical for a street driven car. But I do regret not just laying down the extra smack for a Hyd. retro-roller camset. I could have gotten more lift with a shorter duration with roller, and gained a good 50 Hp plus more torque I think. Heads are ported already.

But an expensive upgrade.....

Did I mention I need to get a rearend for it?? That's my next project. Also an "expensive upgrade". lol

TA

iTrader: (1)

If you really wanted to cheap out on the hyd roller upgrade, you can snare a set of stock Hyd roller lifters from an '87 or later junkyard 5.0 (even the TBI cars had them) and the guide spider for a song. You can swap roller lifters on different cams, they are not like flat tappets where they will self destruct because they are broken in to each cam.

However, you will have used parts of unknown history in your bitchen new motor, and they will not be anything trick, just stock hyd rollers. But you are absolutely right, you can get a much more aggressive lift with them compared to flat tappets, and can get more high end power without sacrificing drivablity. I'm not sure I would be totally comfortable with this, but it something to think about.

Maybe someone on the board will set you up with his stock used (known good) roller lifters if he has upgraded, and all you would need would be the guide spider and the cam.

Good luck
Troy
So Cal

Confuzed1

iTrader: (4)

Yep - you're right Troy, I wouldn't want to throw used parts at this engine. I have too much $$$ into it to risk something failing right away.

If I had gotten the roller setup, I would have used retro rollers. I've seen people use stockers, but it would still require me to drill holes for the lifter girdle (or guide spider) since my block doesn't have the mounting holes for it. I'm not sure what would need to be done for a cam thrust plate too.....and I'd most likely have to get the heads worked again to hold up to the higher lift a roller cam would give me.

Nah, too late. I'll just have to deal with what I have for now. Most guys would think I'm nuts for spending as much as I have so far on this car....I know my wife does!!

Although the engine looks great on the stand right now, it'll look better when I get it in the car and mash the gas!

racereno

I think you had a good, solid plan based on a truthful assessment of how you'd REALLY be using the motor. The Dyno proved that your plan was successful. Your butt will tell you that you were right when you get the motor in a vehicle.

Build for max avg torque under your usable rpm range and let the hp fall where it will. You did this and I think you'll be REAL happy.