Well, the job is complete, at least enough for me.The 572 made good power but isn't tuned for max effort.I learned that the carbs were not the best for the application. They ended up with 140 primary and 153 secondary jets.I don't have the dyno sheets yet and I did manage to get some photos but The camera won't record sound.No big deal, i will have sprint man or someone else post them for me.I wound up with 1117 hp @ 6500rpm on pump gas at 29deg total timing.Full advance was in at 2300rpm.18 pulls were made.The pump gas reading was with 11.8 lbs of boost.On race fuel, the engine made 1166 hp with 13.6 lbs of boost.Timing was at 30 deg,tried 35 but it did not respond.Larger jets have been ordered and their absence limited the boost we could run.I really don't need another 50 hp so I think we can wait for a couple years and then make some upgrades.The engine would Idle at 850 rpm on race fuel and a little higher on the pump gas.I don't have the sheets in front of me but the torque and hp band is very broad.I was unable to use the same exhaust header as in the boat, but pretty close,2.5 primary and 4 inch collector.The collector on the boat headers have 4.5 inches.I tried it with the air cleaner and it caused it to richen up a little,which is good, and dropped the horsepower by 27 on the top end.The intermediate circuit was very fat and we changed the bleeds and even tried it with them out.I learned a bit more about dyno tuning and alot more about the carbs.The cam peaks around 62-6500 and the power difference is minimal between the three.It made 1000 horse starting aroung 5600rpm.I will see if I can get the pictures and sheet posted soon.The air fuel ratio was around 12.5 but my egt's are running on the high side.about 1430- 1470 at wot.I was told this could be the result of not enough coolant flow through the engine(iron heads).I was using a csi electric pump, I did not have my water cross flow tube for the inlet. water temp was around 160 and oil temp was at 205.Carbs made for the application would have netted the 1200 hp level.The vacuum pump worked well but I have to get an air bleed valve to regulate it.It registered 14 inches at full power and the man said he wants 10. The right side valve cover was tapped in the rear for this measurement.The air intake charge temp was between 145 and 160 deg,the intake manifold has holes in each runner for mech fuel injection,this is where we probed it. A single inlet on each end was used to feed and exit the cooling water through the superchiller. I was told to try and inprove on this to drop the intake charge temp,any suggestions welcome.water pressure was around 15-20 psi.I could feel the discharge water temp climb as engine load increased.Plugs were ngk 8's gapped at .042 and a crane box with msd coil,wires and distributor.I will continue when the dyno sheets and pic's are posted.
Man those are great numbers. Do you run the water through the intercooler first? Also if your cam is 114 lobe seperation the exhaust temp will be high. Do you have your cam specs? I would like to see them.
Malke sure when you put it in the boat ir runs up to 6,500 or just a bit more.
Congrats
Would you like to SuperSize your order?
Yes, oh, and it's to go.
That is a good report can't wait for the sheet's and the pic's.Thank's for sharing with us.Later
Cheyenne 572
del 51, i would like to probe your brain a little bit. my buddy has basically the same motor a blown 588 chevy.we were wondering what your static comp. is, cam specs, what size carbs why such big jets my buddy has two 1150's with 99's and seems to be ok. that is before he got a hold of a lee intercooler and with only 7psi of boost. also with your superchiller what size hose were you using to feed it. have been told if you use dual -12 or -16 inlets it is possible to get manifold temperature down in the low 100's to high 90's, superdave was very antimate about that. i know that is a lot of questions any info would be helpful it looks likle you are making the big power.
Thanks for the support,I am fired up.I was just hoping for a little more.I guess that is why it was dynoed to begin with.I looked on the dyno sheet for the cam specs and it said refer to blueprint sheet.So,I asked and was givin the old answer,proprietory info,"Hey, you can tell me"I wont tell anyone", you know the story.He did tell me duration was around 255 deg and 114 separation.I could degree it,but i don't want to piss him off.I cranked the motor over while pre oiling and the lift did not seem too drastic.Valve sizes are 2.25 intake and 1.94 exhaust.Merlin/jenkins 345 cc heads with 125cc chambers,cnc ported.The pistons are from CP and have a slight dish to them.I had these coated with thermal barrier and skirts were givin some slippery shit.I think the comp ration is 7.8 to 1.The intercooler was run separate from the engine cooling water.it had a 1/2 inch inlet and outlet. The outlet was necked down with a hose clamp to provide some back pressure.The out flow was very good.Todd said the Lee intercooler was a better unit than the superchiller.I would think increasing the flow with 2 more lines would work better.I can do some fiddling around and see what will work.Thanks for the input. The carbs, I bought them from holley direct about 5 years ago and had used them on my 468-871 engine.They are model 9377,1150 cfm.Get blower carbs or something with more capacity.These do not have power valves.And one more thing, pulleys,I have only 6 so testing could have been better with a larger selection.60 bottom tooth and 53 top for pump gas,11.8 boost.60 bottom, 50 on top for the race fuel 13.6 boost. I am positive on the pulley count but the second boost number may be a decimal or two off.
[ December 21, 2002, 04:38 PM: Message edited by: DEL51 ]
DEL51, Sounds like some great HP numbers you got there. I bet it was big fun watching that engine scream on the dyno.
There is no need to be dissapointed. Dyno numbers are just that, dyno numbers.
How well the boat runs is the deal
Hey unchained,it was neat! the Cops stopped by at ten after 10 to tell us to stop for the night. I worked 12 hrs for each day on my regular job and then drove an hour to the shop to begin testing. It was rough, 2-20 hour days back to back wiped me out.His muffler is a 12ft by 12ft concrete/cinderblock shed with a bunch of old tires to dampen the sound. I have some Ideas on how to improve this setup.He is in an industrial park, but has a residential neighborhood surrounding it.How is your project coming along? Are you going to run it in the same boat? I am concerned with the weight of my engine.I have 19ft tunnel, centurion its going in.I may have to play with the engine location.Can you coat the exhaust on the turbo engine?
Info, you're right. I just had a 1200 number in my head.I know the torque is what is really important as far as the pump is concerned.I may have more than what I really need.If that is the case I could slow down the blower some.I have to go and get a powerball ticket.I guess you can't win if you don't buy one.
Posting Permissions
Reply With Quote