Dave Robsons Challenger R/T

Dave-R · Post by **Dave-R** » Mon Sep 27, 10 10:33 am

Mick70RR wrote:Dave, you should have Helicoiled those loose threads while you had the heads off. You could still do it but it but it would be a struggle with the heads on.

Didn't notice they were loose until I fitted the headers. I was expecting them to be tight with the paint in there but they ran in by hand easily.

Dave-R · Post by **Dave-R** » Mon Sep 27, 10 10:35 am

ANTON wrote:Dave
If use studs to stop the leak you could cut the header flange to slot on the stud with a large flanged nut and the you should be able to fit the headers.

Would have to custom make the nuts. But I like the idea. You guys with small blocks don't know you're born.

challenger · Post by **challenger** » Mon Sep 27, 10 7:33 pm

i know your views with studs dave, but at least with the stud it does seal the thread in the cyl head, as you know all ive ever used is studs on mine, to remove headers i either have to put 2 nuts on them and wind them out like a bolt or remove engine mount bolts and raise the motor, yes its a pain in the arse but this way ive never had one leak or come loose. also as you see in the pic ive cut the studs down small as poss so i dont have drain the water removing the header, with you having manual steering surely you have more room than me and maybe able to remove the header without raising the motor, just my

Dave-R · Post by **Dave-R** » Mon Sep 27, 10 8:05 pm

It is something I will try if all else fails.

I resist using studs because my 2-inch primary pipes make it pretty tight.

Even without studs I have to jack one side of the engine up at a time to move the headers enough just to get a socket onto the head bolts. I badly scrape the headers and steering every time.
On the passenger side (where my leak is) I have about 5/16ths between the pipes and the inner wing. But even tighter is the torsion bar. The pipes are only just clearing them (couple of mm) which makes manovering the headers pretty tricky. Although with the engine jacked up high this side does in fact drop out of the way easier if not competely (I need to remove the trans dipstick tube to drop them right out of the way).

Again the passenger side inner fender (and primary pipes) get scraped badly every tme i move the headers. Studs would make it worse without a doubt.

Anonymous · Post by **Anonymous** » Mon Sep 27, 10 8:15 pm

Yea , very difficult if not impossible using studs on a big block...............one more thing Dave , YOU SHOULD OF HELICOILED EM BEFORE YOU FITTED HEADS.

.......don't understand the paint in the thread thing.

Dave-R · Post by **Dave-R** » Mon Sep 27, 10 8:47 pm

Hey Adam. If I want to clutch at straws just humour me.

Anonymous · Post by **Anonymous** » Mon Sep 27, 10 10:28 pm

Dave wrote:Hey Adam. If I want to clutch at straws just humour me.

Sometimes you're just too honest for your own good

Dave-R · Post by **Dave-R** » Fri Oct 08, 10 3:51 pm

Pulled the spark plugs last night. Found something interesting.

I have NEVER had the exactly the same colouring on all my spark plugs in the past. There is always a couple slightly richer and leaner looking than the majority.

With these new metering plates in the outer carbs I now have 8 plugs that are all absolutely identical in tip colour.

The wideband O2 sensor told me the mixture was OK. But obviously that is an average of 4 cylinders on one side. I usually get #1 plug looking lean and #5 looking rich on that side. So when I jetted the front carb one size leaner and the rear carb one size richer I couldn't see how that could make the mixture better. Logic told me it would actually be worse.

But it did work.

Every plug is spot on. Magic.

Just got to stop this bloody water leak now.

Anonymous · Post by **Anonymous** » Fri Oct 08, 10 4:58 pm

good work dave im sure you will get there in the end

Dave999 · Post by **Dave999** » Fri Oct 08, 10 6:08 pm

if you get the option
rather than a helicoil
use a timesert or a case saver

this is a blind hole fat metal insert bigger than a helicoil
a threded hollow metal cylinder

you wind em in far enough to take the full length of the bolt and by their nature they seal off the hole like a stud
but take a stud or bolt in the internal thread.

they are usually used on bike or VW engine cases in situations where the torque you want to put on the stud is way to much for that diameter of stud tapped into alloy

fatter the stud the more the thread into the alloy can take but thats no good if you can't use fat studs due to clearance up the barrel or in the head (big bore barrels on a VW for exmaple. don't want studs exposed to combustion chamber at the head ideally you'd use 10mm but you are limited to 8

if you are limited to 8 mm studs they are going to pull out

but if you put in a 10 or 12 mm case saver.
you can crank on the torque on that stud and it won't pull the 12 mm steel case saver out which is wound in and machined flat with the gasket face
other end is exposed to sump oil so you need it sealed

kills two birds with 1 stone if your heads have enough meat to take the drilling necessary

not gonna get one in with the head on though

Dave

Anonymous · Post by **Anonymous** » Fri Oct 08, 10 6:40 pm

we use timeserts at work they work great in ally but not so sure on cast iron thats why i didnt mention them

Dave-R · Post by **Dave-R** » Sun Oct 17, 10 12:07 pm

If it does not sell by Christmas I am going to try getting the head welded.

The other head was stitch welded by Dave Hughes when he ported them and it has been no problem since.

If that works I will still have the car for sale but at least I will be able to drive it in the spring.

Guy · Post by **Guy** » Sun Oct 17, 10 1:22 pm

Sounds like a good plan Dave

Anonymous · Post by **Anonymous** » Sun Oct 17, 10 3:48 pm

Pm me your address and I'll try and get some dye penetrant and indicator sent up to you buddy, the stuff we have you'll need a black UV light

Dave-R · Post by **Dave-R** » Sat Jan 29, 11 12:27 pm

Well the car may be sold in principle but I still have to fix it and make sure it is running well for the new owner. It's the least I can do.

So it will be off with the old ported iron heads and on with a pair of stealth heads. These will be used in "out of the box" condition as they flow as much like this as my old ported heads.

I will only be fitting the matched valve springs for my camshaft and lapping the valves in. The rockers will need a little adjusting on the shims to center them exactly on the valve tips and I will need a new set of spark plugs as these heads require long reach plugs.

The big job will be removing the pistons and having the quench domes on the piston tops machined down. I can't remember how far they protrude above the deck but I need them to be flush with the deck so that with the gasket in place I will have 40 thou quench space in the head.