View Full Version : blower motor
gyellow88
02-21-2011, 04:26 PM
Hey yall,
I have a few questions regarding a current engine build! Iam building a 540 chevy with a gm 8-71 blower! As of now I just have the block,blower and carbs. Iam going with an eagle 7.5-1 blower rotating assembly and a custom grind blower cam from comp. Iam trying to make 12-1300hp on race fuel but if need be (with suggestions) i could run alky inj. my main question is what do you guys recommend for heads? i have heard since i will be making all my power from the blower that i dont have to go crazy with the heads? some say i could run stock 454 heads with some work done to them? It is a strictly mud racing truck so the engine doesnt get run often or for very long! I look forwrd to hearing suggestions. Thank you very much
kwkracing
02-21-2011, 06:05 PM
your not going to make a 1200 with 7.5 to 1 static compression and a 8-71 blower. your blower is to small. compression is to low and you will need some nice heads
reddog358
02-21-2011, 06:16 PM
Here is a couple of points of interest you may want to consider while building your motor.
1200-1300 hp with a 540 using an 8/71 will be hard to do with that low of compression unless you have a super nice hi helix 8-71 blower. You could use some N2O to help get there with the above combination using race gas. Done this before with a 355 small block running a 6/71, made about 1050 hp which was good for 5.00 in the 1/8th.
If you want to run injection and alcohol, you will need to bump up the compression to at least 12- 12.5 still using the 8-71. As far as heads go, if weight is not an issue, some iron square port heads will work fine, alum heads will be better if some N2O is used. Stick some 2.250 intake valves and some 1.9 - 1.94 for the exhaust in the heads. A pair of Dart 360s would be a good head to run. Hope this helps a little! Let me know what kind of specs are on your cam. Later
blowninjected540
02-22-2011, 03:00 AM
Just built my 540 made 1347 hp on the dyno. 12 to 1 comp, dart 380 pro 2 heads with 871 with 11 lbs of boost. on alky. you are really pushing the eagle rotating assembly to its max at 1200 hp (would go with better stuff)
gyellow88
02-22-2011, 05:58 AM
so what rotating assembly do you guys think i should go with? and the cam sepcs i wont know for a little bit cause i wanted to get my head setup first! And blown injected 540...you made that much power on just 11pounds?? i was thinking i would have to run in upwards of 20plus pounds ??? Thank you guys for the responses i greatly appreciate it
bbchevy
02-22-2011, 07:06 AM
If You Go Injcted Alcohol?You will Need @ least 11.0.1!
Thats Your BEST DEAL!
Callies Crank,BME Alu.Rods,J&E Pistons.Buy the Crank already Double Keyway Cut for a Blower Hub.
I Used the DART 360's for Years,They work!Just be CAREFUL you DONT End up with Someones Elses JUNK.............?
Cam 114* Lob Sep,325-335 Duration,anything in the Mid 700's Lft,up to .800.I Personally Dont like that much,but Hey?
Heres a Deal of OLD?
Broke my GOOD Alu.Heads Years Back,Thru on a Set of Port Matched w/Good 2.250 Int Valve,990 GM Cast Heads.And Picked up almost a FULL Tenth?
Hope this Helps?
Later
G 8)
i have a beretta with a 871 bds stage 2 blower no strips, afr 335 heads,714 solid roller,509 ci.8 to 1 comp with 2 dominators on race gas,15 %over on blower,have only made a couple passes the best was 8.15 165ant that was a shut off run at about 900 feet,so of you use some of the hp to weight formulas it says motor is about 1100 to 1200 at flywheel.
bbchevy
02-22-2011, 10:36 AM
i have a beretta with a 871 bds stage 2 blower no strips, afr 335 heads,714 solid roller,509 ci.8 to 1 comp with 2 dominators on race gas,15 %over on blower,have only made a couple passes the best was 8.15 165ant that was a shut off run at about 900 feet,so of you use some of the hp to weight formulas it says motor is about 1100 to 1200 at flywheel.
?
If You Shut it OFF @ 900'and still went 165MPH.....?Then You would have been WELLOver 200MPH,That would been a Good 1 to keep the Pedal MOUNTED!
What was the Lifting Reason..........?
Later
G :?
running through the converter hit the 8000 limit chip
kwkracing
02-22-2011, 11:53 AM
bme aluminum rods, ross pistons, big dart or brodix's, a teflon stripped blower, enderle bird catcher and 12.5 to 1 static compression and you will start throwing axles and driveshafts in the mud, lol. Tell us how much you plan on spending?
gyellow88
02-22-2011, 12:38 PM
imm runnign 2.5ton rockwell axles so breaking axles is not a problem haha. But all the setups you guys are running sound really reasonable! Im not running for a timeslip like you guys are so being on or off 11hp wont hurt me too much so if i could push high 1000 or low 1100s i would still be really happy so im not on a strict motor setup! i will be running a 454 block and ike i said it will be a race truck so it barely gets run and wen it does its for a maximum of 5 minutes! so any other suggestions is greatly appreciated!
blowninjected540
02-22-2011, 02:56 PM
so what rotating assembly do you guys think i should go with? and the cam sepcs i wont know for a little bit cause i wanted to get my head setup first! And blown injected 540...you made that much power on just 11pounds?? i was thinking i would have to run in upwards of 20plus pounds ??? Thank you guys for the responses i greatly appreciate it
With 20 lbs of boost it shoild be around 1500 HP, running a callies crank,olliver rods, diamond gas ported pistons, comp custom gride cam, buy it right the first time. I read this Quote: " ONLY A RICH MAN CAN AFFORD TO USE CHEAP PARTS" Not calling eagle parts cheap but if you are looking at that kind of HP, better parts are gooder.
gyellow88
02-23-2011, 06:59 AM
i completely agree!! i dont want to go cheap the first time! blowninjected 540 can i pm you with some other questions? youve been a big help!
promod45
03-19-2011, 05:28 PM
before you buy crank look at howards cranks they are really good, they are made here in states and machined by callies and the price is alittle cheaper for the same quality crank..good luck