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Topics - Dunc the Funk

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1
Dan Dishon's Transmission Den / Driveshaft UJs
« on: May 19, 2023, 02:04:25 PM »
Hi, I'm looking at replacing UJs as I'm fitting a stronger yoke & one is a little worn. They're 1350 style.
The toughest looking ones seem to be the solid steel ones, sold by Jegs & Summit. They list parts by Dana Spicer, Inland Empire & Strange that all look the same. Cheaper from Dana Spicer though.
On Jegs these are:
Dana Spicer 094-5-1350X $24
Inland Empire 537-5-1350X $35
Strange 873-U1641 $38
Our current ones look like these: 890-961350 $56 (complete with red seal band) which have held up well. Maybe I should get them but the others 'look' better quality.

Anyone got opinions on these or recomendations on something better?

2
Roo Man's Room / King pin / spindle bushings
« on: July 16, 2022, 09:59:40 AM »
Hiya

I need to get the king pin bushings replaced on our drop tube axle. I've taken the worst one apart, the kingpin was held in with a grub screw & it all came out easy. The kingpin mics at 0.75" & does not appear to be worn. The bushings are 0.75” inside diam & 0.75” length with an extra 1/16” flange on the bottom one to take the vertical load. The bottom one is shaped like a hollow top hat, fitted upside down. The top bushing is a simple cylinder.

Can anyone tell me where I can get replacement bushings from or what car these may have been off originally?

3
Front Engine Dragsters / Blower restraint straps
« on: March 21, 2022, 11:05:04 AM »
Since our car is not running nitro and not a funny car it's pretty unlikely our blower restraints will ever be exposed to a serious fire.

But is there any technical advantage in fireproofing from silver restraints over black nomex ones?

4
Dan Dishon's Transmission Den / Rearend gear ratio advice wanted
« on: December 30, 2021, 09:56:32 AM »
We have run 7.5s in the quarter at around 180mph this season & we are wanting to go a bit quicker next season.
We have a powerglide, 3.7:1 gears & Hoosier 33x15x15 tyres. We are now crossing the finish at near 8000rpm, which is our current rev limit.
I'm thinking of going to 3.5:1 or even 3.4:1 rather than winding the motor higher.
What gears/rpm do you folks use and what diameter tyres?

5
Altereds / chassis mods - length vs suspension?
« on: November 11, 2021, 10:11:50 AM »
Since we removed the coilovers from the rear of our car & made it solid, it launches FAR better. However it is now prone to bouncing in the shutdown area or if the driver has to get off the throttle in a hurry without pulling the chute first.

The wheelbase is 113". I'm thinking there are two ways to go which might improve the situation:

1. Extend the wheelbase to 125" & replace the beam axle with the modern triangulated axle mount system.
2. Keep the wheelbase short but add front suspension (most work I guess).

Any opinions on what would be best?

6
Altereds / First drive in my altered!
« on: September 22, 2021, 05:04:29 AM »
On Friday I finally elbowed my driver out of my car & did a launch, a half pass then more-or-less a full pass. I'd tuned the car down a bit, blower 3% under instead of 3% over, 25 degrees of timing instead of 35, lot of rear wing. Even so I got a 1.15 60' & 5.45 to the 1/8th. 1/4 ET was 8.99, slowing to 122 as I groped for the parachute lever. What an awesome experience! I knew the acceleration would be brutal but didn't know it would feel so good!

I can't add any pictures as this seems to stop the topic from being created (tried 3 different browsers on 2 pcs).

Next day the driver is back in the seat for our races, I tuned it to 2 more pbs, 7.52 then 7.50. We were hoping to get into the 7.4s but the speed was not good, we think the valve springs are getting tired.

7
Spud Miller's Cave / Reducing boost - reduce fuel?
« on: August 26, 2021, 11:40:42 AM »
Currently we run our blower just 3% over, 33 teeth on the crank & 32 on the blower. This gives us about 15psi of boost. I want to reduce the power for a newbie driver (me) and I have a 26 tooth pulley. If I put that on the crank & the 33 on the blower that's 20% underdriven. I will also put the timing to 30 or even 28 degrees & add more wing angle. Should I take a guess at taking some fuel out of it or leave the tune alone then lean it if I have to?

8
Altereds / Back on track at last
« on: June 24, 2021, 12:03:44 PM »
At the end of 2019 we'd had enough of our MSD 10+ not playing ball at start-up. So we fitted a 7AL just to test, it seemed to work. At the end of May 2021 we got back to the track at last. With the motor freshened up by me, some new 6' long wheelie bars also by me, ladder bars dropped a hole & a better wing I was hoping the car would work better. It took me a whole weekend to get the tune leaned enough to burn ok with the 7AL, people were literally telling me it couldn't be done. However the driver said it was much more under control now so I persevered. We ended the weekend with a new PB (just) 7.94 @ 177. Two weeks later we're back to the track with some more jets & pills from Good Vibrations, got the hat/port split better & we ran 7.778 @ 175mph! Well pleased with that. Next job - ditch the coilovers, make the rear solid mounted & lower.

9
Altereds / Front caliper seals?
« on: March 16, 2021, 02:04:22 AM »
I have just noticed that we have a leak on one of our front brake calipers since it's been stood. The leak is from the centre of the rear, it looks like a narrow part of the piston protrudes and that's where its leaking. The single piston floating calipers came with the car & are probably quite old, I believe they are from Strange. On their website they show a seal kit that fits "all" their single piston calipers (B1260RK) and this is retailed by Summit. Can anyone confirm if this kit should work or where else to look?

I tried to post this twice yesterday with photos but it didnt work so I'm leaving them off for now.

10
Altereds / What axle oil to use?
« on: March 14, 2021, 08:02:42 AM »
I'm just putting the 9" rear end back together & thinking about buying some 85w-140 for it. I was wondering what you more experienced folks use, for example is Lucas mineral Heavy Duty ok or should I step up to, say, some Red Line synthetic?

11
Matt Shaff's Engine Shop / Gear drive runout?
« on: June 07, 2020, 03:53:49 AM »
Hiya, just checking some stuff before re-assembly. Last year we had the cam dowel come out & I found that the hole in the gear drive cam hub was oversize. I removed the cam, drilled the cam hole larger then reamed it & the hub larger, fitted a bigger dowel & it ran ok. I thought I really ought to look at gear backlash & runout while I have time & the motor is fully apart. Rotating the crank & cam with the gear drive bolted down shows no tight spots but the backlash does change a bit during rotation. I removed the cover again to check runout on the cam gear. It's a maximum of 4 thou (or +2 to -2). Anyone know if this is ok?

12
Matt Shaff's Engine Shop / Rod bearing clearance
« on: May 23, 2020, 02:39:46 AM »
My local machine shop checked our crank & gave it a very light polish. The guy said the rod journals are at standard. The bearings used by last year's rebuilder were standard (Clevite CB-743HND) and the previous year's builder were one thou thinner (CB-743HXND). The rod manufacturer (MGP) says we need 3 to 3.5 thou clearance. I assumed that when we first got the engine it had been set up loose for traditional thick oil so that seemed ok. Anyway I used fully synth 10w50 the first year & 15w50 last year with no major issues.

This year I ordered King CR 808HPND in standard but before fitting I thought it would be a good idea to check clearances with last year's bearings. I only have Plastigage. Everything was dry & clean & correctly torqued. I was surprised to find clearances were between 1.5 and 2 thou. Now I could use Clevite thinner bearings as above or King equivalent (STDX type) but firstly availability is not so good and secondly 4 of the bearings will still be a little tight at around 2.5 to 2.75. My question is would it be better to have a thou or two taken off the rod journals now then I can use the bearings I bought & not have the same issue next rebuild? I'm planning on using 10w50 oil as the crank is already set for 3 thou.

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Matt Shaff's Engine Shop / BBC Main Stud Life?
« on: May 16, 2020, 09:18:40 AM »
On a blown methanol 517ci BBC with 4 bolt steel main caps on an iron Gen IV truck block with aluminum rods, probably around 1000hp and operating at 7000-8000 rpm max, what sort of life expectancy would you give the main studs e.g. in terms of rebuilds, seasons, runs?

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Matt Shaff's Engine Shop / Cause of fretting on main caps?
« on: February 07, 2020, 01:11:46 PM »
We only put 13 passes on our blown methanol BBC last season. I was surprised to find serious fretting had occurred on caps 2,3 & 4. 4 was loose in it's register.
As far as I know this did not happen last season when we probably did 20 odd passes. Is there anything I should think about with the tune that may have caused this?

15
Matt Shaff's Engine Shop / Removing crank hub spacer
« on: November 18, 2019, 05:14:33 AM »
My BBC has a steel crank hub with a large-flanged bolt. In front of that there is an aluminum spacer for the blower pulley to sit on. The bolt will not go through the outer part of the spacer bore where it steps down. So in order to remove the hub I need to remove the spacer which seems to be a press or interference fit on the hub. I've been thinking of applying heat with an electric heat gun to expand the aluminum and also fabricating some kind of 2 legged puller that will fit. Anyone got some tips on removing the spacer?

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