Thread:

New blower questions

This must be a low rpm deal..??

I ran a 565 @ 12% over with a stripped 14-71 and a 200hp shot of niitrous all on 92 pump gas and a water meth kit coming on at 6psi..... rann killer and zero problems!! 88-92 jets in a pair of 1250's and 27 on timing!!

Originally Posted by whiskeybent hondo

Now that the smoke has cleared on that other bad deal,.... (most of you know what im talking about) I visited Don Hampton a few weeks back and gave him a deposit to build me a brand new 14-71!

Why a hampton 14-71?

1) Hampton is THE O.G. blower guy

2) Out of all the blower manufactures I called,.. Don was the coolest guy to speak with. Lee at littlefield was a close second, but the straw that broke the camels back is #3....

3) IMO Don Hampton has the best looking blower on the market.

4) Hampton dosent make a 10-71 to replace my old one. If im going to change my distibutor to a crab anyway I might as well go straight to 14-71. Plus a 14 will be better for a future build

Ive got a blown 496 BBC, eddy rpm rec heads (soon to be darts), isky #rr-652 cam on a 112 grind set up on a 108 center, 8.5 to 1 comp, bds comp manifold, Twin holley dominator # 8896 stage three carbs with 96 jets square, 32 degree timing.

I know that nothing is linear, but here is my thinking: I ran my teflon stripped 10-71 @ 10% under. Im not sure what the boost was but accourding to mooneyham it was on the edge for pump gas. It ran great. The new blower is not going to be stripped. These are just rough calcs but...

10-71 is roughly 469cuin X .10 under = 469-46.9= 422.1 cuin
14-71 is roughly 522cuin X .18 under + 533-93.9= 428 cuin

For LAKE bench racing purposes only, lets say the above calcs are close.

Here are my questions:

1) If I back down timing to say 28 degrees, could I turn the 14-71 a smidge faster than 18 % under?

2) The motor is already pig fat...but how much more boost can you get away with by setting it up fat for pump gas?

NO!... I WILL NOT BUY A SMALLER BLOWER

-Whiskey

Lil E, just one question. We're you hitting the bottle last night?

You guys can't compare a 565 to a 496 here. They're not even close.

Lil E, just one question. We're you hitting the bottle last night?

LOL...

Originally Posted by whiskeybent hondo

Nope just thinking about boats instead of doing something more productive like sleeping.

Were you hitting the bottle last night?

p.s. sorry I wasnt able to come by the BBQ

We hung around the house after Joe and Chelsey left....BBQ was fun....today, I'll work around the house and start playing with the new stuff for the motor

Originally Posted by whiskeybent hondo

This is the point of the thread. If you run a big blower on a small motor like mine what can you get away with? I have seen where guys back off the timing, fatten up the carbs and get away with turning the blower faster.

My uncle had a 468 with a hi helix 14-71, 7.5 to 1, dart heads, and its lived for over 10 seasons. The new owner saw over 15lbs on pump gas and no intercooler. The only explaination Ive recieved of why it works is the motor has no timing and its way rich.

My question is ,..I know Im running another point of compression compared to the above example, but how much boost can you get away with by backing off the timing and giving it some extra fuel?

thank you

There's a big difference between 7.5:1 and Dart heads and your 8.5:1 and the Eddys. You can't say "I know I'm running a point more compresion BUT..." Yes, you are, and that's significant.
Boost is only a reference to restriction and you're going to make a lot more bost a lot sooner with your set up than Danny did. 6# boost on your engine will not be the same as 6# on his. You're basically trying to put a 1471 on a street engine with w big lazy cam. The cam is going to help bleed off some cyl pressure but you're still going to have to underdrive the heck out of the blower. Timing and fuel are all part of the game but totally dependant on the combination.
You're taking on a bit of a challenge here. It's usually a good idea to learn to swim a little before jumping in the deep end. I dunno...call me crazy...

Originally Posted by blownboosted

This must be a low rpm deal..??

I ran a 565 @ 12% over with a stripped 14-71 and a 200hp shot of niitrous all on 92 pump gas and a water meth kit coming on at 6psi..... rann killer and zero problems!! 88-92 jets in a pair of 1250's and 27 on timing!!

That 27* deal.....any particular reason? I was taught that number 30+ years ago on several completely different set-ups and have heard that number from several different sources over the years. They only thing i have noticed is pistons seem to begin to rattle a little at idle in a street car/decent muffs situation.
Sorry for the thread jack....not really

Like most lake/river boaters the wow/bling factor is a big thing. I am not going to comment on the boost #s or anything mechanical..I also have a hampton blower. It meets my needs and I would be really be happy with it if the case would not grow fur every time it gets a little water on it. Water spots are a bitch to remove. Don't even think about putting your cover on the boat...out of all my prep to go to the water, I spend more time cleaning the case. The end plates and covers are easy to maintain. I thought the case oxidizes from the alloys that are used. For me I would never use a hampton again in the marine enviorment..just my 2 cents...I still have it, I just don't like it for the reason I stated.