KRE head swap dyno results
 

Another attempt to get some solid swap numbers went to the wayside. The dyno showed 452 RWHP at 5650 RPM. But the rpms and power was jumping all over the place. After making various adjustements and 8 attempted pulls we called it quits. As soon as the secondaries opened things went goofy.
The consensus is my torque converter can't hold the power against the dyno and was slipping intermitently.
The only other parts that changed besides heads was new push rods. Timing and Q Jet rods were different.
These numbers show a 77 RWHP increase from a well ported 6X-4 head to the 310 CNC 74CC KRE D Ports dynoed on the same machine.
I wanted to swap to 1.65 rockers and see results but things just weren't working right. I have another cam to swap to this winter and am looking to still be on target for 500+ RWHP to start next season.

Hmmm, exciting and disappointing at the same time! What convertor are you running (assume a conti 10'')?

Yeah Continental 10". I have emailed them to see if it's normal for a power change of 100+ HP could do this since it was made for less power.

nice numbers ron!!! I am sure they will come up even more next year with the cam change to take full advantage of the 310 flow!

Yeah, those numbers were still with the 1.5 rockers as well.

can you post copy of your dyno printout graphs w/numbers from before to after now ?

I didn't print one from today as the needle was all over. i have the one from 2 weeks ago that we had the same problem and it showed 430. I changed rods and timing and opened the caps on the cut outs for todays pulls. I will try and post them now.

Ron H

I do not think it is your vehicle that is causing your problem. I believe that the load control on the dyno is not tuned properly and cant hold the extra load. I have run on a Mustang dyno and have seen unstable loading.
I would find a differant dyno before I would suspect your torque convertor.

FWIW,
Karguy

Yeah we tried a few things to get it to work. The dyno guy said he had a similar problem with a turbo Jag. The converter was slipping.
This is a dyno pack machine. I can't help but think it was the dyno brake not being able to hold on and was slipping causing the problems.
I can't get my scanner working hopefully I will have it by the morning.

Ron - I didn't realize you selected the 74 cc heads - what compression iron vs al.?

John

''6x heads have a 93cc chamber. KRE's are 74 cc. 9.4 to 1 to 11.1 to 1 change. 6x heads never had the crossover plugged. But I did plug the crossover on the intake.''

Brought it over from the first thread.

Ron, what's the rest of your build look like? Gotta be happy with that kind of power for sure! (Well, at least I would be)

I hate gynomometers.

I am not a huge fan of them right now either.

75 455 .030 over, Stock crank, CAT rods, SRP Pistons, U/D Solid 247/255 @ .050 110* LSA .525/.540 lift, !.5 HS roller rockers, KRE 74 cc D Ports, RPM Intake, Cliff's Q Jet, Pertronix Dist with MSD Cap and Coil and 6AL box, 2 Step , Doug's headers, Continental 10", TH400 with a kit, Ford 9" with 3.89 gears, 33 spline Moser Full Spool and Axles, 3" Pypes exhaust With Cut Outs and Race Pro Mufflers, CSR Electric water Pump, Alum Rad with Dual Fans, Centerline Auto Drags , Skinnie fronts, M/T 275/60/15 Drag Radials, QA1 Coil Overs front, Summit 3 way Adjustable rear, Calvert Racing Split Mono Leaf Springs, Slide A Links, Full interior, Full Steel except Fiberglass Hood, 8 Gal Fuel ell, Mallory 140 Fuel Pump, -8an lines, Battery In trunk, 100 Amp 1 wire Alternator.
This winter U/D 255/263 Solid 108* lSA .540/.556 cam and 1.65 rockers. Freshen bearings, rings, fill the block, maybe upgrade Rods but I think they will be OK.Add a windage tray and crank scraper, new Oil pump.
Rebuild trans and add a brake. Send in Converter to match new combo.
Completely strip car, blast, clean up rust, install Roll Bar, Paint.
Hopefully go racing in Vegas/Phoenix mid-end of March?

We have very similar combos,Im curious to see what yours dynos at with the 1.65s ,thats going to put you really close to .600 lift.

I will be if the HS 1.65 rockers are 1.72 as many have said they are. that would put me at .593 after .026 lash intake and .610 exhaust with the other cam. I really wanted to see how much more power i'd make swapping them with my current cam.

452 is good power am also interested to see what the other upgrades will do. You are running more cam that what I have now (HR288). Shame there isn't a track for you to test on also. Thanks for keeping us informed.

Tom

Actual HP...
 

Ron, I was surprised when I ran the numbers so far! Your 452 RWHP comes in at 587 FWHP! This is assuming a 23% driveline loss.

Is this correct? If so then the combo seems to be working! I'm not sure if you can make the 650HP you seek without going roller? Ron wrote... " I wanted to swap to 1.65 rockers and see results but things just weren't working right. I have another cam to swap to this winter and am looking to still be on target for 500+ RWHP to start next season." The reason I say this is 650 minus 23% is 500.5

I think it's very possible to get 600 FWHP as there are a few guys on PY getting there! Congratulations and keep up the good fight! Good luck! JD

I am calculating 18-20% loss. 510 RWHP is my goal and with 20% loss that's 612 on the engine. If it's 18% loss I would be 601.8 on the engine.
This is with an RPM intake as well.
To make more I definately would need more cam, carb and intake volume.Probably bigger headers as well.