Author Topic: 1080 dragster bench racing  (Read 1179 times)

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Offline gschuld

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1080 dragster bench racing
« on: November 18, 2015, 10:14:23 AM »
There has been some great information, mostly from Frankie ;) (dragracer), on getting into the mid 10s with an ET Street restricted class bike.

I'd like to dive into fantasy land for a bit and "bench race" a full slick sohc dragster.  Let's take Benton's D&K dragster that he picked up from David Morgan this summer.  It was drag raced every year for nearly 35 years straight since David bought it in 1978 and retired it in fine running form just a few years ago.

It has run everything from a stroker crank RC 73mm cast block 1160 motor on gas to the 12.5:1 compression 890 motor running on methanol it retired with.  It ran consistent 9.80s and mid 130s mph with the 890 motor for years bracket racing it.

The chassis is a 1975 D&K 72" dragster.  5.5" slick on it with long ladder bars.  All up weight should be around 350lbs minus fuel and rider.

So let's say Billy makes use of that 73mm bore RC cast block he picked up recently and puts together basically a clone of Frankie's motor, 327 cam, but with a vintage ported but totally reworked K head.  Back cut gears, good clutch, etc.

So the D&K chassis, 5.5" slick, long ladder bars, with an old school 327 cammed 1080 big bore motor with 10.5:1 pistons running on good non oxygenated race fuel.

How would you set it up and how well could it perform, say, under the Man Cup Pro ET rules (they allow wheelie bars and slicks)

George

PS.  And yes, I'm just trying to start trouble. ;D

« Last Edit: November 18, 2015, 10:31:54 AM by gschuld »

Offline dragracer

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Re: 1080 dragster bench racing
« Reply #1 on: November 18, 2015, 10:47:59 AM »
I see no reason why that bike shouldn't run high nines given the use of todays electronics, carburetion and a decent set of wheelie bars built specifically for the wheel base of the bike. I've often wondered what numbers my engine would net in a wheelie bar chassis. I'd then be able to leave the line full throttle off the two step while the bike is on the bars through the 60'. I'd guess low 1.30 to high 1.20 something 60' times and low 6's in the 1/8th mile. Bill bought a decent looking stock chassis wheelie bar bike not long ago. That's the type set up I'd like to try one day. Lay downs worked great back in the day but they soon realized that sit up bikes with proper crank to axle dimensions worked 100% better.

I'd say go for it George. If I didn't already have 4 wheelie bar bikes in the shop already, I'd be on the Honda path myself.

Offline gschuld

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Re: 1080 dragster bench racing
« Reply #2 on: November 18, 2015, 11:02:58 AM »
Don't look at me like that Frankie :o.  ....;D, I have other plans that will take me far away from the dragstrip scene.  It would just be great to see a vintage sohc dragster or two back out there.

George
« Last Edit: November 18, 2015, 12:04:37 PM by gschuld »

Offline dragracer

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Re: 1080 dragster bench racing
« Reply #3 on: November 18, 2015, 12:42:10 PM »
Don't look at me like that Frankie :o.  ....;D, I have other plans that will take me far away from the dragstrip scene.  It would just be great to see a vintage sohc dragster or two back out there.

George

Brother George,
If you just come out and make 2 passes down the dragstrip with us, those other plans would go straight out the door. Just ask Wilbur. He's been a faithful member of Bill's pit crew from day one. He also crewed for me and the wife once at Bradenton and did a great job. This last race, he made a decision to actually race his very nice street bike. No, Wilbur didn't try to break into the 10's or set any records. He instead, set his mind on learning how best to get his bike down the track consistently to turn on the win light. He was hooked after the first pass. He lowered his ET's every pass and eventually won some rounds. I don't think you'll ever see Wilbur standing on the sidelines again- he's addicted and there is no rehab for drag racing. I really felt good seeing Wilbur sitting patiently on his bike in the staging lanes- seemingly formulating in his mind how he was going to go through every motion of his upcoming run. He had a determined look on his face and did one hell of a job for his first race on his bike.

Get an SOHC bike ready and join our enthusiasm.

Offline bear

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Re: 1080 dragster bench racing
« Reply #4 on: November 18, 2015, 03:38:46 PM »
Don't let Frank turn you to the "Dark Side" George.
Stick with us road racers mate.

Still looking for your pics Frank.

Cheers,
Brian
The older I get the faster I was.

Offline gschuld

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Re: 1080 dragster bench racing
« Reply #5 on: November 18, 2015, 04:25:05 PM »
Don't worry bear, my main focus is still on the turns. 8)  I am working on a , well, creative situation...

So for curiosity, once you introduce full slicks and long ladder bars, the benefits of the weight shifted forward on the more modern upright/extended swingarm layout is reduce somewhat compared to the dragster layout right?

Certainly in ET Street, where no bars are allowed, the more aft weight bias of the dragster chassis would present a serious disadvantage regarding wheelie resistance.  I get that.  But for a slick/long ladder bar setup it shouldn't matter as much with only +/- 100 RWHP correct?

George
« Last Edit: November 18, 2015, 04:33:03 PM by gschuld »

Offline dragracer

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Re: 1080 dragster bench racing
« Reply #6 on: November 18, 2015, 05:49:23 PM »
George, here's a picture of my pro ET/super comp bike. Stock frame with raked frontend, double club foot swingarm. It even had the stock steel tank, cut down stock seat pan and duck tail on it.

The bike ran 5.40's in the 1/8th mile and 8.80's in the quarter mile.   

Offline POPS 911

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Re: 1080 dragster bench racing
« Reply #7 on: November 19, 2015, 04:38:38 AM »
FRANK in the 10's :  Tell these dream builders about them car tire, slider, NOS, TURBO [ Kenny Schwartz ], two step, throttle stopped , " GOT BRUCE KZ ", Canada racer Conapacki  a racers who run those 5.10 in the 1/8 being dead on = a guy with a 8.21 was 11 on the run sheet Sundays MAN CUP in the 8.20 class of killers ...... These folks are DRAGRACERS with many win tickets and passes down 1320'. Never seen a person get a win ticket on the MSP DYNO  brought to the track at PRO-STAR. Did anyone bring a DYNO to the MAN CUP races this season ????

Offline POPS 911

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Re: 1080 dragster bench racing
« Reply #8 on: November 19, 2015, 05:41:32 AM »
FRANK 10'S: Get on e-bay type in 231699296441  could be a heart transplant for a tired SOHC750