Dyno testing tomorrow, what will it make?

Quote:

---

Good luck with it, I don't have a clue on HP or TQ, but am interested

---

Quote:

---

What happened Cab?

---

The motor didn't make any where near what I expected The printer attached to the dyno was out of ink so the operator downloaded all the pulls to a thumb drive and took it home so he could send me the copys via E mail. He sent me a picture of one sheet he printed at home and of course I can't read it I ask him this morning to send me copys of all the front sheets, the torque and HP summary sheets, so I can look at all the reuslts to post them on here. I'm hoping he sends them to me this morning The motor started off making 500+ ft.bs from 2500 RPM to 5000 RPM and around 470 HP on the first couple of pulls to seat the rings, it was really fat(11.2 to 11.6 AFR) at WOT through the entire RPM range . We change the upper RPM limit to 5500 RPM and then to 6000 RPM finally. We leaned the first carb.(4781-7) down several times, 4 jets sizes on all four corners and I then opended up the high speed bleeds on it as well as leaned the idle mixture screws down quite a bit also. The motor liked leaner I change the plug heat range from a RC9YC to a new set of RC12YC, it liked that also, aluminum heads and 9.7 to 1 compression ratio so it will run on 87 octane regular No compression = no heat so the plugs needed to be hotter I changed the carb to another 850 D.P., 4881-2 I had and it made a little more power, not a bunch, but it was leaner(12.3 to 12.5) and more consistent on the WOT AFR all the way from 3000 to 6000 RPM which ended up making more HP and torque. I think we saw 512 HP and 550+ ft. lb on the gauges on the dyno, without the printed sheets I'm really just guessing though I'll try and post them as soon as I get them Dang baby cams don't work The car has power brakes hence the Comp Cams XE275 HL cam so I will live with the results The customer is thrilled with those reults,the motor idle at 12.+ inches of vacume at 1000 RPM I wish that I could have talk him into removing those dang power brakes so I could have put a little bigger and better cam in it, the motor has to have fuel and air to make power, more air, more power More to come shortly, hopefully

Quote:

---

The cam IMO is abit small for the combo, I'll say 510-515hp & 530-540 lb. torque.

---

Looks like i got pretty close, Don't be disappointed in those #s cab, The torque is high & thats a plus right there, I'd rather give up 15-20 HP then lose 20ft. lbs torque, 12 inches vacuum is "dead on" for the XE274H series cam, The XE284H gives around 10 inches, Its worth about 15 or so more HP over the 274, But you tuned 40+ HP out of it with just tinkering & jetting, Thats an A+ right there

Cab, what was your final jetting & air bleeds on that 850?

It'll run great!!

Quote:

---

Greg, I tested that motor with non ethanol 91 octane, not regular Sorry for the misleading comments on him being able to run the motor on regular He wanted a motor he can do burn outs in a 1969 Coronet super Bee That motor , with the proper torque converter, should shred his street tires As far as retarding the cam, all the Mopar motor I've dyno tested and done the testing at the track, didn't like the cams retarded That cam is ground on 110 LSA, I don't have the cam timing notes on that motor now but I think I put it in around 105 to 107 ATDC( 3 to 5 degrees advanced) on the intake lobes I'm anxious to see how it drives in the car I've had 446 and 452 C.I. iron headed pump gas motors( with bigger cams, similars size carbs and intakes) make more HP than this rascal did

---

Quote:

---

I have another 3.90 stroke 440 block pump gas motor I will test next month, if the money allows that On this one the RPM intake probally limits the peak HP RPM, I looked at the sheets the dyno operator sent me, there hard to read by E mail or Photo Bucket It looks like the motor made 506 HP at around 5700 RPM and 570 Ft. lbs at a RPM I can't read, I'm guessing between 4000 to 4500 RPM As far as the jetting on the 4781-2( the second carb. tested) I had 78 in the front with a 6.5 power valve and 86 in the rear with no power valve and no other mods. I'm aware of or did other than having the choke blade removed. On the first Carb, 4781-7 I did open up the H.S. bleeds to right at .028 or .031, CRS It ended up with 76 jets in the front and 74 in the back with power valves in both metering blocks like stock I think thats the jetting and H.S. bleed sizes, CRS again It really suprised me when the earlier carb did better with stock jetting than the later carb. did I guess that is why we test I will switch manifolds on the next motor, take off the RPM and put on a either a Mopar M1 single plane or my old favorite, the Weiand Team G single plane I'm hoping to get some printed copies of those results soon so I can read all the data instead of parts of it All in all it was a good day, nothing broke and it made 40 more HP than it started out with BTW, making the AFR leaner did reduce the torque but it improved the HP, at the track by using a wide ban gets the same results Leaner is faster than richer. We don't race dyno ,do we My old M.W.stocker out ran the other cars in the same class that had hot spark plugs and a rich mixtture Test, test and test some more, the spark plug and time slip is your freind

---

Quote:

---

I forgot to add the weather was horrible that day, it was raining outside, the B.P. in the dyno room was reading 26.35 most of the day and the humidity in the dyno room was 34 %, air temps where cool, under 65 F. The dyno operator pointed out that the correction factor was 118 % during the tests, he said had not seen it that bad before I've always used that dyno in the cold of winter, not intentionally, but that was when I could get the motors on it. It would be at or under 32F with a high pressure cold front blowing through I had ran into similar weather conditions down in Ontario,CA on Vrbansic Brothers DTS dyno once, it was raining outside and the motor on the dyno was down on power(by 20 to 50 HP) compared to other motors I had built using very similar parts and build specs. with better weather The customer is happy so I shouldn't be crying, should I

---

Yeah BP was horrible at 26 no doubt, That would explain it wanting less jet. If the customer is happy, thats what counts