Messages

16

Front Engine Dragsters / Re: Front engine digger wheelie bars

« on: September 25, 2017, 09:54:19 AM »

for those running bar 2", how are you raising the bar for towing etc ? we've killed a wheelie bar wheel due to rough pits etc, would like to be able to raise it up quickly

17

Spud Miller's Cave / Re: Hilborn stack idle problems

« on: July 18, 2017, 03:34:43 AM »

Are the butterflys square in the hole.   Back off on blade shaft adjusters...loosen every blade and tap lightly with a small hammer handle or plastic screwdriver handle to seat the blade. you will hear it seat....do them all ....re tap each and tighten.
Is the idle bypass stuck???

new butterflys set at 0.002", can't see /feel any visible wear in the bores.  Slight wear in the front of the throttle shaft where the cable connects so we're looking at bushing it.  Also considering getting a sycrometer to check how even they are.

This is a stack system, so in terms of plumbing at the pump we have inlet in, primary bypass, shut off return, main line to BV and secondary bypass off the BV.  If by idle bypass you mean the secondary bypass off BV, I'm led to believe this is blocked at anything less than 25 degree throttle opening ?, so should be blocked at idle.  In terms of it's operation, coming off the burnout and run, there is no surge or stumble so we assume it's opening at part throttle to reduce the fuel pressure on throttle closure.

18

Spud Miller's Cave / Re: Hilborn stack idle problems

« on: July 18, 2017, 01:42:10 AM »

I'd disconnect the spark plug cables, one by one, trying to identify if there's one cylinder contributing more than the others for this elevated low idle. That could help, for example, to catch a vacuum leak between intake manifold and cylinder heads.

thanks will try that

19

Spud Miller's Cave / Re: Hilborn stack idle problems

« on: July 17, 2017, 08:56:36 AM »

Just re-visiting this issue.

Firing the car at home, the idle in neutral was still 2500rpm, blip the throttle and it doesn't come back down on it's own and will sit at 2800rpm until you drop back into gear.  We looked for vacuum leaks, resealed the manifold, split the throttle bodies and used new gaskets.  Fired the motor and it's no different, 2500rpm in neutral, around 1800 -2000rpm in gear.

We ran the car again this weekend and managed to get 5 passes on it.  The converter is loose enough that it can be driven at low speed and staged but I just don't like it that high.  The BV is already set at 25% and is milking oil on each run.

This is a Hilborn 2 1/8" stack system on a 421cu in SBC, iron heads, 32 degrees timing locked out.  Running the quarter it ran 9.005 @ 148mph which is the best ET and MPH on the engine from when it last ran in an altered. 

I'm launching off idle, it revs well, no stumbling, pulls hard and stays lit in the shutdown, the xxxx thing will just not idle below 1800rpm.  Where do I go next ?

20

Roo Man's Room / Re: ground clearance

« on: June 09, 2017, 01:08:57 AM »

cheers Roo, kind of hard to visualise at the chasssi kick up from the front of the motor which is where the blocks are.  I've ordered tires so will see how it goes.

21

Roo Man's Room / Re: ground clearance

« on: June 08, 2017, 03:39:47 AM »

Just bringing this one up again.  I've currently got 3.5" at the motor plate and 2.5" at the lowest point (which are actually rub blocks 3/4" off the frame rail).   I'm going from a 33" tire down to 31", so that's 1" reduction in rolling radius.   Tires are MT ET's , do you have any idea of the likely ground clearance on the 31's ?

22

Dan Dishon's Transmission Den / Re: shut down with PG

« on: June 06, 2017, 04:52:01 AM »

If the motors not running, you have no trans pump pressure.  Even if you shift into neutral, you still have components driven by the output shaft rotating at speed with no pressurised lubrication.  It might not kill it, but it won't be good for it.

23

Front Engine Dragsters / Re: Weight bars

« on: June 04, 2017, 02:37:35 PM »

No way would I move the motor out, it's purposely built to emulate a 60's digger.  I have 38lb in a weight bar, some shot to fill the axle and more lead for a weight box.

24

Front Engine Dragsters / Re: Weight bars

« on: May 03, 2017, 02:25:56 AM »

adding weights to balance the car is no bad thing, it doesn't have sufficient weight over the axle to steer at speed or with the chute out.  It was always going to get weight added, it was just a question of how.  I now have 38lbs in my weight bar and with a properly adjusted wheelie bar and some wheel speed, it should calm it down.

High gear is an option, but I'd be concerned at reaction times and trans temps.  I wouldn't do it without a valve body change to retain the transbrake and I don't like leaving off idle.

25

Front Engine Dragsters / Re: Weight bars

« on: April 25, 2017, 09:33:18 AM »

well, I had a little win today, scored 30lb of used lead for the equivalent of $12, so tonight I'm smelting more lead and going to try making shot  

My axle is a 1/4in thick, anybody see an issue drilling and tapping a 3/8th hole to fill it with shot ?

26

Front Engine Dragsters / Re: Weight bars

« on: April 24, 2017, 10:26:24 AM »

Steve Field is running about 50lb in his car, which is 148 inch, so I would try close to that best bet is have a word with him.

spoke to him last year on it, and he added the weight after the mishap off the line.  I can't fit much more out front so I think it'll have to be a box in the chassis or drill and fill the front axle.

27

Front Engine Dragsters / Re: Weight bars

« on: April 24, 2017, 10:12:18 AM »

If it is hitting the bar hard enough to break the wheel it sounds as if the bar is set too high and/or the car is hooked too well. I generally like to run the bar so that the wheel is around 1 1/2-2" off the ground but that number will vary with how rigid the bar is. I would try varying the bar height and/or the tire pressure to get a bit of wheel speed leaving and stop the car from rotating hard.

Roo

your correct Roo, it was a midnight special welded up hours before the event, bar was probably 3in off the ground and we'd run out of adjustment.  I'll get it down lower, just need to source a decent wheel for the bar

28

Front Engine Dragsters / Weight bars

« on: April 24, 2017, 03:29:33 AM »

Last time I ran my car it hit the bar pretty hard, to the extent it broke the wheel.  It's 138in with SBC shorty glide close coupled.  Motor is 420in SBC injected on alky, making c 600bhp and 500ft lbs ish.  Rear gear is 3.7 and it's on 33x10's

Chassis is CDS I have a full size battery ahead of the motor and a moon tank but little else further forward. We knew we'd need weight but hoped to calm it with 3.7 gear.  Before we go back out with it, I'm making a weight bar to mount in the front axle.  Lead shot is expensive so I'm smelting lead roof flashings.  So far I've got it to 22lb and the material I have will see it total 35lb.   

Does anyone have an opinion on how much weight I'll need ?.  If I need any more I'll have to fab boxes to sit in the chassis also.

29

Roo Man's Room / Re: Wedding

« on: April 11, 2017, 07:03:09 AM »

thought this was a welding thread with a typo ... Congrats !

30

Front Engine Dragsters / Re: Trans to Rear Coupler Play

« on: March 29, 2017, 02:05:11 PM »

It worked well for us, but it took some figuring. We remounted the whole deal three times before we settled on this. I did speak to another guy with a similar issue and he used saddles and a heavy zip tie which allowed some compliance. 

I think it's really the door car guys who suffer most  in this regard. Wider rear track, more torque reaction and a solid mounted trans just becomes a stressed member.  Use a stock glide with a thin bellhousing and they start cracking bellhousing.  Then they hack them off for a Ultrabell, problem masked.