Dave Robsons Challenger R/T

Dave-R · Post by **Dave-R** » Sat Aug 07, 10 11:29 am

OK so now I am interested......

Dave-R · Post by **Dave-R** » Sat Aug 07, 10 11:47 am

The thing is my heads have 85cc chambers. So I don't see how i will get enough compression for the cam with these heads. They are 88cc.

Dave-R · Post by **Dave-R** » Sat Aug 07, 10 11:53 am

My pistons....

68cc = 11.7:1
73cc = 11.10:1
85cc = 9.90:1
90cc = 9.50:1
978 grams with pin
Effective dome volume: 1.8cc
Compression Height: 2.057
Deck Clearance:-.025"

All compression ratios are based on a .030" oversize and a .039" compressed gasket thickness.

I was using a 20 thou head gasket with my 85cc chambers to get the compression.

AllKiller · Post by **AllKiller** » Sat Aug 07, 10 12:02 pm

I think you need to do some research Dave....

Straight into the 10's mate

miss the 11's

I got mine from Indy
...they call them Indybrocks, they buy bare castings from Edelbrock and build them for quality control

I had mine mild ported and big valves...i believe Blue has them on his car now.

Pete · Post by **Pete** » Sat Aug 07, 10 12:10 pm

...and loads of weight off the nose

Dave-R · Post by **Dave-R** » Sat Aug 07, 10 2:29 pm

But will need new pistons. May as well replace the rods too. Re-balance.

There is a couple of grand gone straight away. I don't even have the $300 for the pushrods let alone the £120 for the replacement tyre. You guys live in cloud cuckoo land.

drewcrane · Post by **drewcrane** » Sat Aug 07, 10 2:30 pm

Pete wrote:...and loads of weight off the nose

80 lbs i believe

ANTON · Post by **ANTON** » Sat Aug 07, 10 5:41 pm

Dave
Why buy a new tyre when the one you have can be repaired with a pull through mushroom patch. I have load here at home with the adhesive and golf ball abrasive wheel.
I have use these mushroom plugs on by bike for year and have ridden at 190mph with them fitted and never had any issues.

AllKiller · Post by **AllKiller** » Sat Aug 07, 10 6:46 pm

Dave wrote:There is a couple of grand gone straight away. I don't even have the $300 for the pushrods let alone the £120 for the replacement tyre. You guys live in cloud cuckoo land.

I dont Dave..thats why my 505 cubes isnt built yet...you dont have to do it straight away, regardless of how much you and "WE" might like it to be built.
Its a wish/want list...
I take care of what needs sorting at home etc first, this is a hobby and nothing else

I ve not even thought about the Cudas fixes needed, since it went back in the garage. £££

Pete · Post by **Pete** » Sat Aug 07, 10 6:46 pm

Dave wrote: ...... You guys live in cloud cuckoo land.

Best sell the car then, or put a 318 in it

Dave-R · Post by **Dave-R** » Sat Aug 07, 10 7:31 pm

ANTON wrote:Dave
Why buy a new tyre when the one you have can be repaired with a pull through mushroom patch. I have load here at home with the adhesive and golf ball abrasive wheel.
I have use these mushroom plugs on by bike for year and have ridden at 190mph with them fitted and never had any issues.

Clearly you haven't seen the tyre.

The side walls are melted.

Dave-R · Post by **Dave-R** » Sat Aug 07, 10 7:31 pm

Pete wrote:
Dave wrote: ...... You guys live in cloud cuckoo land.
Best sell the car then, or put a 318 in it

Probably the most sensable suggestion yet.

Pete · Post by **Pete** » Sat Aug 07, 10 7:45 pm

Well, let's face it; you are getting on a bit and your racing days are nearing an end.

I guess you should settle for a point or so less compression and make the car a nice cruiser

Light blue touch paper and retire...............

Anonymous · Post by **Anonymous** » Sat Aug 07, 10 8:06 pm

Pete wrote:Well, let's face it; you are getting on a bit and your racing days are nearing an end.

I guess you should settle for a point or so less compression and make the car a nice cruiser

Light blue touch paper and retire...............

I thought that Pete. Maybe Dave should by a nice clean straight six dart with bench seat and snogging knob on the steering wheel. You're no spring chicken anymore Dave, there is a lot to be said for beige slacks and hush puppies you know

Anonymous · Post by **Anonymous** » Sat Aug 07, 10 8:20 pm

Dave wrote:
Talking of pushrods.
My existing 0.049" wall rods are supposed to be good up to 400lbs spring pressure. My springs probably exert around 340lbs at my lift. Probably too close to the limit.

So I am going to get some 0.083" wall thickness rods instead. They should be good up to 800lbs of pressure.

Bent plenty of pushrods on that 605" , wall thickness was .085" with spring pressures around 250 closed/700 open , had Manton send me some .145" wall pushrods , seems those .045" wall pushrods are on the limit with 400lb open pressures.

Dave , mill the heads along with the pistons , still plenty of meat on the crown , job done.