476 replies to this topic

[Struggler]

Thanks everyone for the kind words, I appreciate it.

[Struggler]

I ended up backing off on the crush a bit so they could do their job properly but I do feel this is a temporary fix. Will probably turn up some alloy items one day.

[Struggler]

Where are your uppers mounted ?

 

As mine is a UC I used the factory mounts, I assume you have some sort of aftermarket bracketry ?

[Struggler]

Here is another video I just found.

 

Check the LHF wheel when the car leaves at about the 40 sec mark.

 

http://www.youtube.c...h?v=EV0HlgUS9uc

Edited by Struggler, 29 May 2013 - 08:54 PM.

[Struggler]

Been a while since an update so here goes.....

 

First up a couple of pics from the APSA meeting.....

 

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Now we have that out of the way.....

 

I finally decided to get rid of my block mounted mechanical fuel pump and go with an electric one.

 

I purchased a Magnafuel 500 secondhand off eBay and really should have known better. After phone calls to the US and a heap of new parts I got it back together and running. I removed the fuel tank and got a -12 bung welded in and replaced the horrible plastic filler cap with a weld-on aluminium item. Made up a nice bracket to hold the pump/filter combo up and wired it in with a couple of relays. I used a single -12 hose to the pump and reused the single -10 to the regulator. I'm still using the -4 bleed from the regulator back to the tank and the pump has a separate -8 bypass that had to be plumbed back into the tank. As a precaution I now have 2x -8 rollover protected vents.

 

I gave the pump a bit of a test run and must have pumped about 10L in about 30 seconds ! This thing pumps some serious fuel volume ! Hooked it all up and adjusted pressure to 7 psi at the carbs so will see how this goes now. Pressure was rock solid, unlike the mechanical pump which was all over the place.

 

Not really sure when I will get to the track next, hopefully they will announce a Test'N'Tune soon and I'll give it another stab. As well as the fuel pump change I will also take a spare set of recessed tip spark plugs and see if this helps my miss in the top end.

 

Here is a pic of the revised boot with the new pump.....

 

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[fatslr]

Great work Andy I see you have got the bonnet secured now too lol

[Struggler]

Thanks guys.

 

Yes Garth, added another pair of pins to the centre of the bonnet. A bit late though, it has a small tear on the leading edge. Not too worried, I guess it makes a cool battle scar !

[Struggler]

Wow ! Almost 6 months since my last update.

 

I have been pretty busy with other stuff and didn't get the car back to the track until the rained out Nostalgia meeting in November. I also tried to get to another Test'n'Tune but it too was rained out. I finally got to a meeting on the 20th December (another Test'n'Tune) and got a few passes in.

 

First a bit of background. At the APSA meeting I was running slicks which definitely picked up the cars 60' times but the drivers side tyre rubbed itself to death on the forward guard lip and I couldn't reuse them again. This meant going back to the Drag Radials. The fastest the car had previously gone with the Radials was 9.72 at 137 so I guess this is a fair baseline to test any changes against. I still considered the car to be running rich which is what was causing the top end miss/blubbering so recently pulled the carbs apart again and made a few changes, the most significant was dropping the jet size down to 150 in all corners from 160/164. Sounds like a big change but its not really for an alcohol combo. I also cleaned up the idle considerably with some air bleed and transfer slot revisions.

 

First pass was a write-off with ridiculous wheelspin requiring me to back off totally and trundle away.

 

Next pass was still a little skatey off the line but still managed to power on for a 9.65 @ 141. Engine ran cleanly the whole pass and maintained fuel pressure as it should. A definite improvement over previous runs.

 

Before the next run I removed the baby 6"x2" air cleaners and fitted a Shotgun styled forward facing alloy scoop (Thanks Brett !). I had long considered the tiny air cleaners a restriction and was keen to see if removing them showed any improvement. Out I go and reeled off a 9.48 at exactly143 MPH. Bearing in mind the Drag Radials are a good 2 tenths behind the slicks in ET this means the dirty old 350 is making some serious power and the air cleaners were in fact a restriction but not as bad as I had initially thought..

 

Now for the bad news.... the engine had developed a strange blow-by problem at idle after the first pass. On the return road it was quite noticeable below about 1500rpm but once the engine got revved up it seemed to dissipate. After the last pass it looked like the engine was on fire it was that bad. I pulled the breathers and both sides of the engine looked like chimneys on a steam engine. Due to oil-downs and rain the meeting was canned so I couldn't get another run even if I wanted too. I loaded it up and came home.

 

The next day I fired it up to get it off the trailer and the problem was immediately evident. A walk around the car at idle confirmed I was at least one man down in the firing order on the passengers side of the engine. I drove into the garage and started pulling spark plugs and doing a comp test. They were all good, around 160psi, until I got to No.7. He struggled to show 20-25psi and that was only after a few rotations. I pulled the valve cover and checked the lash, it looked fine so I connected an air line to a fitting I use to pressurize the cylinder via the spark plug thread. No air rushed out the carbs or exhaust pipe, it was all the crankcase....

 

Bit of a mystery why the blow-by goes away at engine speed but I have a theory as to what has happened, will pull it down to confirm when time allows but suffice to say it isn't going to get any better !

 

While washing the rubber off the guards before storing the car I also noticed the sway bar rubbers had failed, exactly the same as Mumbo has described above. I will need to have a good look at this as well.

 

I will also add I think I have found the limit of the standard UC front disc and caliper combination. I usually have to wait about an hour between passes and this gives the brakes plenty of time to cool down before they are called upon to perform again. After my first aborted run I cruised straight back to the start line and had another go. It was exactly 6 minutes between passes. I had a seriously nervous moment after crossing the MPH beams and trying to slow down ! I did just get the car to make the turn in the braking area but my front rims were black from dust and the brakes stunk ! Time to look at a front brake upgrade I think.

 

I would have refitted the N/A 406 for Summernats but unfortunately I lent the convertor for that combo to a customer and can't see any reason to fit it to do a few laps of the fairground and then have to remove the gearbox again when I wanted to race it. Damn my generosity !

 

Not really sure where to head to from here. If I fix the blown combo I'm sure I will need to fit the parachute, trans shield, blower restraints etc required to legally race the car in this form. If I fit the 406 then I will feel like I have wimped out a bit but there is still heaps of fun to be had with it (it still ran a couple of 9's and has room for further development).

 

Anyway I will post pics once the engine is apart and I can confirm or disprove my suspicions as to what has happened. If I can find some online pics from the meeting I'll get them up too.

 

Thanks everyone, hope you all had a great Christmas and enjoy the New Year !

[Stinga]

feels like only a few months ago i saw it at the last summernats. i have the solution for you... give it to me??

 

one vote for keeping it blown here.

 

not blown blown, but blown blown. if you know what i mean

[Struggler]

As I mentioned at the outset, the blower and drive are on loan from a mate. I only own the manifold, carbys and pulley adapter !

 

I have spoken to the owner and he too is keen to see it back together with the blower perched on top !

 

I do have a heap of work here at the moment, most waiting for the holiday period to end. Once I get some of that out of the way I will move ahead on this beast.

 

For now I have decided to swap my Summernats entry over to my old VH SL/E. It has been sitting idle for the best part of a year and could do with a drive !

[LXCHEV]

Glad to hear the shotgun scoop had helped propel this beast of yours to a 9.48, haha, that's awesome!

 

Good luck with your next move forward... so many options

[Struggler]

I honestly expected to pick up a bit more than it did but yes, it did make a difference !

 

Have some stuff to do first but will get around to sorting it out.

 

Watch this space !

[Struggler]

I got an opportunity to remove the engine yesterday, ripped it out and pulled the heads off..... it's worse than I thought !!!!

 

Looks like No.7 has pinged itself to death, possibly by being way too lean, not really sure why just yet but it looks a little messy, molten piston everywhere !

 

All the others look perfect so why just one cylinder would detonate this badly is a mystery.

 

Hope to get the sump off and pull the pistons out in the next day or two and investigate further.

 

Now for some good news, I put a For Sale sign on my VH S/LE at Summernats and moved it on. Got a bit more room to move now and a slightly smaller mortgage.

 

 

 

 

 

 

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[warrenm]

That's a bit nasty looking. Is that a machine mark in the valve pocket or has a valve touched?

[Struggler]

Mumbo, block had already been bored excessively and another bore has ballooned out so it is off to the scrap yard !

 

Warren, well spotted ! All the intakes have touched the pistons. I thought I had enough spring pressure but it appears the added boost is giving them a work out !

 

Here is a look at the piston now its out of the block.....

 

 

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[Tiny]

Christ the bearings are good... Shame about that piston!

 

On one cylinder only?... Quite Odd!

 

And a rear cylinder! Usually rear cylinders get a bit richer because the mix gets shoved backwards in the manifold due to the acceleration, and also the mixture doesn't come evenly out the bottom of the blower (Due to the helix on the blower rotors) hence why they are tending to offset the blowers on the fuel cars to allow the mix to enter the manifold more evenly!

 

How did 8 look? Did it show ANY signs of similar leaning?

 

Interesting stuff! It's a real shame mate, Maybe time for a WORLD or DART block? - high deck... drop the comp a bit... boost it up

[Struggler]

I have been asking around (as my knowledge of blown alcohol combos isn't 100% ! ) and it seems that instead of leaning out it may have been so rich that unburnt fuel has got down under the ring and detonated, lifting the ringland. If you look closely you can see what looks like oxy cutting right down through all the ringlands. Once oil gets into the chamber it drastically reduces the octane rating of the methanol and it will ping away.

 

This would make sense and agrees with your thought of the rear cylinders running richer in a blown engine (which I was aware of). This was the only cylinder with any damage or signs of detonation.

 

I'll be discussing it with some experts next week, I really want to know what has gone wrong before deciding on my next move.

 

I'm still fascinated that the car ran its best times with this damage !

Edited by Struggler, 19 January 2014 - 08:24 PM.