683 replies to this topic

[micklx]

Did you get under 1.45 ?
Hope that huge front bar didn't introduce too much understeer.

[rodomo]

Did you get under 1.45 ?
Hope that huge front bar didn't introduce too much understeer.

Yes! My un-official fastest time was 1:42:92! Thats 5 seconds+ faster than last time.

My mate did un-official 1:40:60! Thats the difference 300+ laps and 15 years younger makes I suppose

Un-official as we are waiting for the results of the last stint of the day so maybe quicker?

The inheriant miss-fire reared it's ugly head again, and again it was 5h1t in the carby. We sorted it out quick this time. I am begining to wonder whether it might be dried up fuel residue because the car sits for 6-8 weeks between races?

Heath came, and went in the car in the warm-up with my mate.
He left in the direction of the station about 1 ish mumbling something about valuing his body more than his head?
Heat stroke? Gee I hope he's ok?

The car did approx 65 laps today (which works out to about 195klms around Sandown) in 10 lap stints. As it was cross entered it meant one jumped out and the other straight in then a 3/4 hour break.

The car pulls 5250rpm on the main straight @175kph compared to 3700rpm with the old diff, you only need to use 3rd and top gear.

With the tyres and suspension it handles more like a go-cart than a speed boat now.

A couple of "fixes" from the day. The top half of the gearstick came out of the rubber bush a couple of times and an oil leak developed at the rocker cover.

The car looked like a used bingo card.

[Heath]

He left in the direction of the station about 1 ish mumbling something about valuing his body more than his head?
Heat stroke? Gee I hope he's ok?

lol yes I was okay after a freezing cold shower and a few hrs spent on the ridiculously delayed, airconditioned trains.

[rodomo]

A bit of an update.

The car has still never been to Winton (Winton or bust! ) but hopefully it will get there on the 12th July

http://www.gmh-toran...showtopic=26198

I have never quite got to the bottom of the "missfire".

It comes in at about 4500rpm and continues in small farts until max revs, 6500-7000rpm, but it is a lot better than it was and is now "tolerable".

There are a few theories as to why, one is that the WW2 being a side fill float chamber starves the carby on L/H turns which is predominately the way Sandown is set out.

But!

The same problem was evident at Heathcote, 1/4 mile straight line.

On my last run of the day, the ignition fuse blew as I held the car through the gears till max revs. The fuse blew as I crossed the line.

The WW2 is being replaced first.
Details and pics to come.

[rodomo]

Bought this 350 Holley, $50.00

Sold these bits on e-bay for $31.00

Got to it with the angle grinder and burrs.

Ended up with this for $19.00


Positives : Bigger float chamber and central needle and seat. Slightly bigger than WW2. Bigger parts bucket.

I need 2 adapters to fit it which adds up to over 1" spacer.

[TerrA LX]

Grinding the top off a holley can actually decrease flow, they spent years perfecting that type of carb, secondly, throw it in the bin and buy a falcon 6cyl type weber as the butterflys open towards the motor, unlike a holley which can restrict flow on a holden 6. JMHO.

Edited by ALX76, 23 May 2008 - 12:25 AM.

[rodomo]

Grinding the top off a holley can actually decrease flow, they spent years perfecting that type of carb, secondly, throw it in the bin and buy a falcon 6cyl type weber as the butterflys open towards the motor, unlike a holley which can restrict flow on a holden 6. JMHO.

I know what you are saying, negative flow and all, but have a look at this:
http://www.holley.com/0-80575S.asp
I think aircleaner design has a lot to do with the negative flow bit.

Have a look way back in this thread at the way this manifold flows.

With regard to the Webber, I don't think that would suit the application at all.
It would be a good replacement for a Varajet maybe?

JMHO.

Edited by rodomo, 23 May 2008 - 12:52 AM.

[TerrA LX]

Oh well ur call, just make sure the vacuum port (present in both manual and auto choke holleys) is still blocked, holley usually used a flat adhesive sticker to block the port on manual choke carbs.

EDIT; did u check fuel pressure when it was missing?

Oh, forgot the smilies

Edited by ALX76, 23 May 2008 - 01:02 AM.

[rodomo]

EDIT; did u check fuel pressure when it was missing?

No I didn't. To be totally honest, the car comes off the trailer and is left.
Then it's a mad scramble to sort out the faults from the last day out in the week before the next day out.

I really think the fuse was at fault. It was a 30amp glass fuse (the only glass fuse on the car) and was blown in the end cap. I can't help thinking it was giving up at high revs prior to blowing as it may not have had a full connection to start with. (And I know better than to use them )

The fuel pump is new and is Goss and is high volume but thats not to say it isn't faulty.

Really what I am doing now is spending some time on it with "known" faults that may be causing the miss and a few "upgrades" that have always been part of the plan.

As I said earlier, the miss is now "tolerable" but I want to get to Winton and have a trouble free day (2 & 1/2 hrs from here)

[rodomo]

Bit of an update.

The car didn't make it to Winton 12/7 (again) due to work commitments.
It did however, get to Sandown on the 13th as a late entry.

An oil leak developed from the rear main seal on about lap 6 or 7 of the day, this made the car look like a 007 Aston Martin (smoke screen deployed) going down the straights as oil was burning on the exhaust. I was followed back to the pits by Mr Scrut. at the end of the stint.

At that stage I didn't know where the leak was and told Mr Scrut. that I thought it was coming from the dipstick tube and that I had fixed it.

He said "fine, clean it off and see how it goes"

At the end of stint 3 he came over and told me it was game over for the day.

I had been chasing this "weep" and had replaced the crappy import no-name chrome rocker cover and side plates with the genuine articles prior to this event. (See pics)

The oil pressure had also been dropping off and the oil light was popping it's head up from time to time. Not bad for a $350 motor though, I can't complain.

All was revealed in the post mortem and the engine is now coming out for a new "up-grade" rear main seal, competition big-ends and mains, lightened flywheel and clutch assy. (courtesy of LC69GTR ), sump and pick up mods, "modified" harmonic balancer and maybe? a different cam.

The harmonic balancer has moved about 8mm, it is 12 months old.



Aircleaner: (from previous posts)



The important things:

It has enough H.P now to make the clutch slip and I can lose it coming on to the main straight (I have to learn that the accelerator pedal is now not an "on-off" switch.

The miss has gone (I'm blaming the fuse)

I now have a new P.B. @ 139.1, previous best was 141.8.

[micklx]

It was good to see the Thunderbolt Grease Slapper in action at its home track. The cloud of smoke following it was most impressive.
I had my VH there as well and can totally relate to Robs first experience a few pages back. The first half of the track is easy enough but get to the end of the back straight doing over 200 km/h and suddenly my foot is drawn to the brake pedal and I trundle over the crest and half heartedly make my way down through the esses before getting stuck into it again through Dandy road corner.
Hopefully next time I go there I can attack that section of the track a bit more and find a second or two.

Hope the engine freshen up goes well Rob, if anyone has a hot 202 cam lying around - Rodomo needs it !

[rodomo]

Update:
The engine is out and the rope rear main seal has zero crush in the block.
I can spin it in the block around the crank

I'm putting this down to the fact that the engine sat fot 2 + 1/2 years.

When I pulled the rear main cap off, the top part of the seal was in 2 pieces, snapped like a carrot!

That solves the oil leak but I don't know where the oil pressure went as the bearings are like new?

More to come.

[MRLXSS]

I hope a V8 is going back in....

[TerrA LX]

The alloy rover

[rodomo]

No V8 at the moment. I am gathering parts to build one though, which also involves another g/box build. (I have gathered the g/box bits)

The oil pressure has been dropping off the last couple of outings and the oil light was coming on after hard braking and turning (Dandenong Rd Cnr in particular)

With the lifter bores, I don't think so but I'll check, it has no taps knocks or rattles. I'm hoping just an oil pump/relief valve issue

The sump will get some work as well.

[makka]

nothing wrong with a rope seal if you do it right, you would have done a few wouldnt ya Rob?

I owe you a PM too....

[FastEHHolden]

Check the cam gear oiler hasn't popped out.

[micklx]

As your lap times have improved and your engine has been sorted, you are spending more time at higher revs than when you started.
My guess is that there is more oil in the rocker cover than there used to be and not enough in the sump.
I would suggest slightly overfilling it with oil, and try not to look at the oil guage. That should fix the problem.

[rodomo]

Ha ha! I did that before the last time out.
It had over 5 litres in the sump!

The sump will have baffles welded in and I don't know the technical terms for the plates across the top of the oilpan and around the pick-up but that will be done too. The maximum volume will be measured in and the dipstick will be recalibrated e.t.c.

The guage has been creeping down after every outing, I new this was inevitable and the rear main failure has simply made it a necessity now.

Edited by rodomo, 04 August 2008 - 10:44 PM.

[rodomo]

Update:

The bearings were the issue as expected, the cam gear squirter is still in place.
I flexi/plasti gauged the rear, centre and front mains and a couple of conrod bearings and the were all out of tolerance. The rear main was the worst at .005"
Fortunately, the crank will see a few more turns.
You can see the wear in the pic.



I thought I'd best have a look at the oil pump and give it a "tickle up".
I gave the end plate a bit of a surface and opted for a better one from a blue engine pump.



I rubbed it on a flat piece of glass using wet and dry and kero. To do this, you move in a figure 8 movement and rotate the plate 1/4 of a turn after 10 or so figure 8 movements. This gives an even finish to what ever it is you are trying to make flat.
I wasn't overly concerned with removing all the wear but rather to remove all the factory machining marks. This way, I know it's flat and I havent removed too much material that might make it warp as I bolt it up.





Next I rubbed down the pump body to achieve a minimum clearance gear to body.
Because of the filter flange, this can only be rubbed in a straight line.
After 20 rubs in 1 direction, I did 20 rubs pushing from the other direction to ensure a "square" finish.



I was looking for .002" gear to body clearance. This is measured by how far the gears protrude from the pump body. As the gasket is .008" thick, I was looking for .006" protrusion. I took .002" off the body to acheive this.



The last mod is the relief valve limiter.
By replacing the bearings and clearancing the pump body, I should gain a fair bit of idle oil pressure.
The relief valve spring will govern the maximum oil pressure but won't give better idle oil pressure.

This mod gives an adjustment of maximum oil pressure by limiting how far the relief valve opens.
The plug has been drilled and tapped and a 3/16 UNC screw inserted to limit how far the relief valve opens. The spring hasn't been touched.
This has to be adjusted hot with a gauge attatched.



More go fast bits. Thanks again to LC69GTR for the flywheel



Next is the balancer mod.

[Heath]

Ahhhh such an informative thread. Love it, looks great mate.