Well,, it did not blow.. but it was quite a bit down on HP (IMO).

The dyno operators were not much help..

460ft/lbs at about 4500.


That was with no exhaust, electric drive waterpump, and 110race gas. EGTs were in the mid13s for most. Some were higher but no more than 80degrees. The BAD vic jr had slightly better egts than the performer rpm.

BSFC was around upper .4s except at the top.
First pulls (1 and 2) are vic-jr with pretty lean jetting
Pull 3 is a dyno-shop holley HP750 that had been on 600+ motors (a little lean up high but slightly better lower numbers).
Tried more timing,, seemed to pickup only 3 or 4hp going from 35 to 39.

Slightly cooler plug for pull 9.
Switched to the performer rpm for the last pull.
Cylinder leak was about 5 to 6 percent.

Download the Win-dyn viewer at http://www.superflow.com/support/sfviewer.exe and you can read the files at dyno

Seems to go to about 445 at 5200 and just stay about there..
Probably going to check the cam centerline.. I could only think that its excessively advanced with that curve.

 

I'm sorry you were disappointed. It's not easy building a carbureted streetable engine that pushes over 1.2 HP/ci. Lots of people think it's easy as falling off a log- until they try it. I build ONLY street motors and I have been where you are. All I can say is- keep at it. I've built motors that looked killer on paper jsut to make less power than some "throw together" combos that shouldn't have worked nearly as well as they did. When you get to where you are now I've found that the right cam is usually where the big power is (assuming the heads are capable of flowing the HP you really want). You may well find that a cam with some very unconventional looking specs makes a world of difference. Single pattern cams, cams with real tight LSAs, and other stuff that seems a bit counter-intuative.

Not being up on your particular engine I couldn't comment much further.

 

if you're really that disappointed with it, i'll take it off your hands.

 

the cam specs are -
Camshaft - Cam motion hydraulic roller

lift .596" intake with 239 degrees duration at .050"
lift .603" exhaust with 245 degrees duration at .050"
109 lobe separation angle
Rev Kit - AirFlowResearch -Hydra-rev
Rocker Arms - Competition cams – ProMagnum 1.6 ratio p/n 1305

CM said it would pull a 400 to a 6000 rpm HP peak with Track1 heads. It most certainly should not be flating out at 5200.

Im to the point that I might not put it back in the car. Ive got to many projects to deal with now..


I might pull a head off and have it flowed and at least CC a chamber or two.

Here are some specifics of the tests

COLUMN AVERAGES

Test: CB40608 - vic jr
Corrected Power
Range: 4100 RPM - 6000 RPM

EngSpd: 5050 RPM
STPTrq: 439 Clb-ft
STPPwr: 420.7 CHp
VolEff: 94.6 %
Fuel A: 94.9 lb/hr
Fuel B: 95.5 lb/hr
BSFC : 0.483 lb/hph
WtrOut: 160 degF
OilOut: 0 degF

COLUMN AVERAGES

Test: CB40608
Exhaust Temperatures
Range: 4000 RPM - 6100 RPM

EngSpd: 5050 RPM
Exh1 : 1345 degF
Exh2 : 1332 degF
Exh3 : 1280 degF
Exh4 : 1293 degF
Exh5 : 1253 degF
Exh6 : 1235 degF
Exh7 : 1332 degF
Exh8 : 1302 degF

COLUMN AVERAGES

Test: CB40610-perfrpm
Corrected Power
Range: 4100 RPM - 6000 RPM

EngSpd: 5050 RPM
STPTrq: 447.9 Clb-ft
STPPwr: 427.9 CHp
VolEff: 97.4 %
Fuel A: 97.6 lb/hr
Fuel B: 98.3 lb/hr
BSFC : 0.493 lb/hph
WtrOut: 154 degF
OilOut: 0 degF
COLUMN AVERAGES

Test: CB40610-perfrpm
Exhaust Temperatures
Range: 4000 RPM - 6100 RPM

EngSpd: 5050 RPM
Exh1 : 1193 degF
Exh2 : 1313 degF
Exh3 : 1324 degF
Exh4 : 1352 degF
Exh5 : 1360 degF
Exh6 : 1246 degF
Exh7 : 1207 degF
Exh8 : 1315 degF

 

You're not too far off. If I had to guess I'd say either you don't have the right valve springs in it (or they are not correctly installed) and are borderline floating the valves. Or you are having ignition problems- nothing really wrong, but a weak link somewhere that's not giving it the Wheaties to get the job done in the upper RPMs.

Valve springs are VERY critical with a roller cam. A rev kit won't make up for the wrong springs or springs that are improperly installed.

Also, let's not forget the simple stuff- did you monitor fuel pressure while making the runs? Wouldn't be the first time a high HP motor outran the fuel system. And could also explain your lean condition in the upper RPMs. Gotta have a gague on it so you know you're holding constant pressure under ALL conditions and RPMs. Trying to tune around an inadequate fuel system is sure to have you chasing your tail for a long time.

 

well.. the springs have 125 seat. At about 350open. Never had a problem with floating in the car or otherwise even above 6000.

They checked the fuel flow several times on their meter, they can tell when its not keeping up.. and there was no indication that it was running out. They also checked the little 3gal tank in the dyno cell,, (which Im not sure how that works),, but it was also staying full).

The fuel pump I saw built on the superflow was based on a magna-something or other and they flow ~400gph..

Fuel flow in lbs per hour never exceeded 230 lbs-per-hr (about 40gph).

Well,, their igntion was an MSD7 and i was using my distributor. A comp 9000 unilite.

After rejetting.. it was actually rich on the topend. BSFCs were in the .55 range.. needed leaning of highspeed airbleeds probably.

Im not disputing the possible conclusion there is some type of physical problem (valve timing or otherwise). but it should have shown up with some type of EGT anomlie. When ever that stuff happenes your going to likely see a big change on at least one cylinder... and that never happened..

 

Post on a message board at www.chevytalk.org and they could help you out more. go the perforamnce section at the bottem of the message board selection.

 

You need a much tighter lobe seperation, from what I've read recently. I forget what mag it was, but they did a comparo w/ a 406 similar to yours. Going from a 110LS to a 106LS gained them around 20-25hp. They went on to say that a 350 would have preferred a 110LS. These tests dealt w/ carbed motors.

 

Oh yeah, what heads are you running? That's kind of important too.

 

http://www.chevytalk.org/threads/sho...&Number=513745

 

The plan originally was use a LSA that would allow vacuum for power brakes (IE not much lower than a 110). I doubt that a 4degree lsa change would get 50+ hp. Changing it from a 109 to a 106.5 in engine analyzer produces the following results.

Increase in torque from 528ft/lbs to 531.
loss of hp from 563 to 555.

It would probably require about 7degrees more duration at 050 to provide a 6000 rpm peak with a 106lsa.

edit
I added 6degrees duration intake and 7 ext to the EA SIM. Torque was 530 and hp was 566 (only up 3hp from the existing cam specs).

The heads are brodix track1s. They flow 270 intake out of the box and about 200 ext.