The Dodge Challenger Message Board

Well in a few hours we're off to the track. We've got a few tweaks and chassis tunes to try out, including special order stiff sidewall slicks. It's going to be a hot one so I don't think well be seeing any personal bests broken this time.
Anyone from here going?
Cheers.
Tig

Not going but good luck!

will be there for the weekend as from tomorrow , like tig we have a few mods n tweaks to try out lets hope it aint to hot !! c ya at the track tig

I have heard Dave ran a ran 9.8@137 (beating his main rival) but put a hole in one piston so is out of action for a while.

Sorry to hear it Dave. Hope he didnt hurt that expensive but repairable KB alloy block. At least he beat his rival. Nice job TIG!

Fingers crossed he will not be out of action long.

Two very nice '70s pairing up together.

Hi All.
Yep we got a wounded bullet OK . Cars still on the trailer at the moment but it'll be going into the garage as soon as I've washed the dust off and changed back to street tyres.
I was racing Dave B when it happend. Going through the top there was a brief misfire then a pop. I looked in the mirror, saw no smoke, checked oil pressure which was normal but noticed I had no vacuum. The engine was still running but didn't sound right so I pulled to the side, coasted round to the return road then pulled over and stopped the motor. I noticed there was smoke coming from the breather area under the bonnet. Dave stopped and we took the bonnet off, it fired up but was breathing heavily. By then given the symptoms I knew I'd hurt it . Towed back to the pits we started logically on # 1 cylinder. Half the ground strap was missing on the plug so in went the scope, what we saw looked like splashes of molten metal. We removed all the other plugs, they all looked to be showing a good mixture with the heat band in the middle of the earth strap. I had jokingly "put in a tune" to drive round Dave B, who kept treeing me (I hate pro lights ) and come down 2 jet sizes 'cause of the heat to see how it would respond. I'm not sure if this is the culprit as all the other plugs are fine and 2 sizes down in 1700ft of air difference from last time out, isn't a radical change at all .
On a good note, we won the round of the Power Tour and got fastest Mopar with an off form 9.81 @ 137.4. To be honest I was expecting to dip into the high 9.60s in the heat, if all was well so I'm not sure what was going on. Wheelies were not there either and we were down on every increment on the ticket. Track opinions were mixed.
Anyway I'm going to get started on the car. I'm hoping the breakage isn't too bad and the cylinder liner hasn't got damaged as that is the hardest bit to fix since KB has closed the doors. I'll post pics later when I'm done.
Next time the car is out it will have some sort of AFR monitoring on it as I've been putting that off for a , if only....
Thanks for reading.
Tig

Dave wrote:Next time the car is out it will have some sort of AFR monitoring on it as I've been putting that off for a , if only....

Yep. You shouldn't leave home without one.

http://www.innovatemotorsports.com/products.php

This one in particular is a really nice bit of kit.
http://www.innovatemotorsports.com/products/lm2.php

These things sample so fast they show individual cylinders on the graphs.

I like that LM-2. You could configure one of the outputs to display the engine load, (measured in MAP Output analog voltage), as you have done with your LM-1 Dave-R.

Just taken the head off, looks like the piston has just broken up. I think I posted a pic of a piston not so long ago where there was signs of detonation. This is the same #1 Piston and it has broke in the exact same place. Combustion sigs on the chambers look spot on (except #1 of course). Looks like the previous lot of detonation has damaged the integrity of the piston and it has just let go

Note the nice even carbon covering on no 3 chamber, no detonation there.


Ouch!!!! Note the distortion on the fire ring.


Remember this, the red felt pen mark is where the damage was.

Looks like the liner is in good shape Dave.(Whew) Have you checked the head for 'straightness' lately? Whats the piston to head clearance? Are you using alluminum rods? Yes, that Fel-Pro held up quite well didnt it! (Please keep us posted as I am building an alluminum block engine and still learning about that alloy's special attention due to the expansion rate)Thanks

Unfortunately there is some scoring and damage to the liner the pics don't show it. Looks like it will clean up though. I've known these blocks go to 4.565 bore (590ci with a 4.5 crank) Though we'll do just whats neccessary, either a new liner and some pistons (it's at least 2 since I haven't taken off the even side yet and # 3 got some debris in it) or a rebore and a set of 10 (2 spare)
Piston the head clearance is .056 but we use a steel rod (Oliver). The only concession we use for aluminium is tighter valve lash when cold (-.012, .006 for the head and .006 for the block). Last time I checked it hot it worked out correct.

Thanks Dave,, and good luck at the machine shop with either a cleanup or a new liner piston ect,

Don't be scared to just bore the one cylinder. Another 10 thou bigger will not make any measureable difference to the tune, compression or balance.

hey tig thats a real bummer mate good job you cut the motor when you did but if we know you, you will be up and running soon, regards to jetting i leaned off a couple of sizes but went slower so went up 4 sizes and picked up 4 10th,s still couldnt get past 12.4 tho struggled to get my motor cool enough with the heat , best of luck matey and thanks for the offer of the starter oh and the beer

Yes Jimbob but did you beat that other '70 Challenger?

yes dave i did, he ran 13.2 i was 12.4, told him to go and buy some slicks think he might need to work on his reaction time aswell 1.24 at the pod he was getting 60ft times of 1.85ish on 3.55 rear but sunday was 1.92 each time, gona have to get me 3.91,s in i reckon and get them 11,s might stand a chance with you then

Well we've had a bit more think on whats gone on. Setting off in 2nd gear won't help (9.91@ 137.89) , Jetting down on a hot day is a no no too We've had issues with # 1 cyl for a while but we've learned that fuel distribution issues with the manifold we are using isn't unheard of . Anyway, staggering the jetting and opening the ring gap will help but best of all would be a fueling system with control of individual cylinder fueling
At the moment it looks like we need a piston, a cylinder clean up and the head skimmed. We'll know better when the engine is totally stripped and checked. Looks like we'll have to miss a meeting or two though but we will return with the potential for more HP since we may use this "downtime opportunity" to do a few earlier than planned "upgrades"

jimbob 440 wrote:yes dave i did, he ran 13.2 i was 12.4, told him to go and buy some slicks think he might need to work on his reaction time aswell

Looks like you were racing a GIRL in the photos? You big bully!

Can't remember seeing this one before?

But then again if I saw it sometime in the last few years I will have forgotten all about it.

dave-r wrote:

jimbob 440 wrote:yes dave i did, he ran 13.2 i was 12.4, told him to go and buy some slicks think he might need to work on his reaction time aswell

Looks like you were racing a GIRL in the photos? You big bully!

she is a lot lighter than me tho great couple dave and denise but then aint we all

dave-r wrote:Can't remember seeing this one before?

But then again if I saw it sometime in the last few years I will have forgotten all about it.

think pete is based around cheshire dave, its a real nice car 440 8 3/4 3.55 rear nice combo have paired up with him a few times now i reckon at some point in the year he be running 12,s, anyhow nostalgia nats is next for me for a bit more bullying

a couple more pics from garys picnic

Well, we need 5 pistons, 3 intake valves 2 exhaust valves. Both heads skimming and chamber work. New bearings and an oil pump and everything needs washing out. #1 Bore cleaned up fine.
So we're getting a full set of pistons so I'll have 3 good spares. Also trying thermal barrier on the crowns, anti scuff on the skirts. Mixture looked a tad lean on the back cyls judging by the colour on the back of the exhaust valves, funny why #1 should go, #2 looked spot on. We may run a bit more ring gap but we'll see. I run 99 jets on the back but the carb will accept a power valve.
Going off the video it looked like it was damaged in the burnout. There was a lot of smoke from the start, but the car sounded "soft" all weekend to me and we didn't make as much vacuum on the gauge as we normally did too. We'll see how it performs when it's all back together.

I'm also re-doing the old 528 as a mild 10.5:1, .650 custom roller cam, Indy -1 headed spare engine. Should be out testing it at York next year, all going to plan.

Gets expensive at this level eh?

hey tig surely with the amount you get the front wheels up that power valve will be come uncovered on the launch , seems to me mate like you had more luck with that old 528 motor

The engine is back together and in the car after a bigger than expected rebuild, hone, all new pistons, valves bearings etc etc. The combustion chambers had to be enlarged to clean up some damage so we've lost a bit of compression (though this may be a good thing). However it appears that we picked up a bit on the flow on both intake and exhaust by unshrouding the valves and with a little work on the valves themselves. They now flow an extra 10cfm ish on the intake, which is nice.
Were out at Avon in 2 weeks, I'm not expecting any pb's streight away 'till the motor beds in, usually 20 passes. If I can get it MOT'd next Saturday, I'll try to put some miles on it and hopefully break it in quicker, ready for the eurofinals @ Pod in sept.
I don't make predictions often but we figure we now have the potential to go hi 9.30's in the best air. Wether we'll see this this year is another thing.
Cheers.
Tig.

Fingers are firmly crossed for you Dave.