2118 replies to this topic

[FLY_LX]

Heat issue hmm..... sounds like you need some more holes

Just kidding. great job as usual.

[neglectedtorana]

Hi Heath,

Great work as always, your dedication to doing every job extremely well is fantastic.

Regarding the stereo interference you were having, what was the issue? Was the interference causing poor radio reception?

I have had poor radio reception for a long time which isn't a big deal as I often drive with engine sound only but something I would like to improve.

Cheers, Tom

[Heath]

Thank you guys.
 
The issue was immense noise/interference through the stereo when the car was running. I guess the injectors, ignition and tacho pulses create all sorts of electrical noise, and the stereo was virtually un-usable when the car was running. I thought it was making the radio reception really bad also, until I realised that the antenna connector was unplugged, lol. I haven't tested my changes yet - so no results to report.
 
I have been busy, stressed, and sleep deprived. Had a session booked into Tunnel Vision in Dandenong for a tune on Saturday which I have been trying to arrange for a long time (his time is not cheap and he's very bloody busy... so I was trying so hard to not deliver him a shitbox).
 
It seemed that sorting out the MAP-reference to the LPG converters was potentially going to minimise pressure variation with the gas (the high vacuum condition at idle could send a signal to keep the pressure relatively low, so that it could be adjusted up for running higher pressure when I'm in a higher load situation. I knew that if the motor actually starts delivering what it should be delivering, it'll be injector-limited and this could be critical.
 
So here's the design in the valley. I figured 8 connections is a huge job, and ugly, 1 or 2 might be a bit too pulsey, but four is a good compromise.

 
I very carefully drilled and tapped some 1/8" B.S.P. threads into the throttle bodies and installed some 90deg. brass elbows into them. I felt like a heart surgeon doing this... the flanges really were not thick enough to have this fitting in them without compromising the O-ring groove, but I just managed to squeeze it into each one.

I found an old length of brass hex that already had some holes in it, put it in the lathe and cut it to what I needed, drilled and tapped the appropriate holes, and screwed in fittings.

 
Then ran the hoses to the LPG converters... I needed to convert the two upper fittings in the photo with these 90deg female 1/8" BSP elbows, but they still had have the right amount of protrusion into the converter to locate a small spring properly, and act as a centre/spigot for the spring, like the old ones did.. This involved putting the 4-jaw on the lathe and doing a bit of cutting.


 
Made up a special spanner to install these fittings... and dis-assembled the lock-offs for more clearance.

 
All done. Ready for the tuner.

 
And, I made it.

 
The day was not without its challenges. I was nervous as hell with an aching gut which made it all a bit hard to enjoy for the first few hours.

• Bolted it up to the hub dyno without issue.
• Started fine, Jason at Tunnel Vision started doing his thing, configuring it and playing with throttle response in neutral etc. before letting the clutch out and doing some low load stuff.
• Jason starts giving it what I thought was heaps (the car started getting pretty loud and revving out to the 7,000rpm which I've of course never heard it do before)
• But the car is only making like... 150, then later 170kW, I find it hard to believe that it can make that much noise and be producing less than 200kW. I wasn't sure if the dyno was set up to display figures that were indicative to him but not actual hub horsepower figures... or my car was a real dud. I didn't want to run in there and disturb/annoy him and ask questions like that, so I just let him be.
• The power slowly creeps up a bit more with each pull every few minutes, and he gets to like... 207kW. He calls me over and says that he reckons the car should get to 250kW by the end of the session. Okay... well that really is a lot less than I was hoping for, but what can I do? That is when I realise he's only using like 35, 40, 45% throttle and even I am not sure whether there's a difference between half and full throttle when you have 50mm throttles on a motor like this.
• Then he does one more pull and calls me over and says "I nearly always check throttle stroke as one of the first things, but this car is so well-prepared I didn't even bother, I'm only getting up to 50% throttle".
• I have a look and realise one of my new brass fittings is fouling on the throttle linkage on the LHS, SHIT! He reckons it's day over because the access is so bad (which it absolutely is), but I ask for some needle files and some time.
• An hour later I've shifted the linkages across (along the throttle shaft) as far as they'll go without being a problem... hard to do with the stainless water manifold installed (juggling magnets on sticks and holding allen key inserts with needle nose pliers and shit hahaha), and achingly slowly filed a nice chamfer onto the new brass fitting. My solution works and it'll be fine permanently I expect.
• Back into action. He warms it up again and starts giving it more berries. Now I realise I was only hearing a diluted version of the real induction sound. Holy shit, the noise it makes is intoxicating.
• The numbers keep rising as he does a pull every few minutes, now I'm seeing 275kW on the screen and it is leaning out at the top.
• He calls me over and says "it likes to be lean", but says he's running low on fuel pressure in these conditions; getting to 90-something-percent duty on the injectors. If the day and my motor went well, this is a problem I foresaw happening, and 275kW is better than 250kW, so this isn't heartbreaking to hear.
• He asks me to crank the pressure a bit, which I do, and it improves things, a few more kW on the screen and a better lambda curve at the top.
• We do this a few times and the numbers/curves keep getting better as he adjusts around each pull.
• He asks me to max out the pressure, which I think some of the injectors struggle with at low duty (I do not understand why, but this is my theory currently). I do this as well, and he does a few more pulls until...

324kW kW at the hubs
 
Holy. Shit.
 
Then we went for a drive. Fastest and most visceral car I've ever driven. If you can hear the big induction sound, you're chalking the tyres unless you're in fourth. 
 
Jason asked if the car had weight reduction because it was performing really well (lol, that was really good to hear someone with a well calibrated bum dyno ask that question), and also told me with an auto and E.T. Streets he reckons it would be in the low-mid 11's. Fantastic. It may get the E.T. streets at some point.
 
So the issues that remain:

• At low load situations, one bank is running lean. It was doing this before, but I think Jason fixed it up with better injector settings, which worked fine until we pumped the fuel pressure to the moon. I suspect the high fuel pressure is hurting the injectors functionality down low, but I'm just a dummy and have not tested this theory yet.
• It dropped a bit of oil, from the front and rear of the sump perhaps? Need to investigate but apparently the floor is never dry after a few hour dyno session.
• Two of the longer trumpets vibrated around so much that they broke my little welds and came loose on the dyno. A few scratches on them, and they need to be welded on better - hopefully I can do so without totally ruining the black anodising that is so close to the welded area. I checked/removed remaining loose ones and lost none on the road test, fortunately.
• My biggest concern now is that the new starter doesn't sound very nice. AND the starter gear is not springing confidently back out of engagement to the home position... it is just moving out of engagement (feeler gauge kind of distance) and sitting loosely there, it is like it needs a spring on the motor shaft, but it does not have one. It has some return-springs on the solenoid, but these are not strong enough to snap it back into the home position. It kind of sits loosely half way between engaged and home and I am not impressed.

[76lxhatch]

...asked if the car had weight reduction...

Nice!
 

There are always issues but I think yours qualify as fairly minor given the amount of work that's gone into the car, definitely testament to the preparation you've put in.

[LXCHEV]

Absolutely - great to see the meticulous preparation pay dividends. Congrats on the results! With that much power, surely low 11's at a minimum - who knows there could be a 10 lurking in this car. And Heath - you know you owe it to us all to get those ET Streets as soon as possible now and hit the strip. Looking forward to that report

 

Well done again for doing something so completely different to the norm, it's totally refreshing.

[Heath]

Short video here with a dyno pull:
https://youtu.be/8HE9RzLcG_4

[Liam S]

Nice work Heath, that would be a lot of fun to drive no doubt.


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[MRLXSS]

Congrats again mate - I hope you're not far off lots of hassle free motoring now!

[Shiney005]

Great stuff Heath.  That car is testament to you doing the hard yards and putting in some serious hours.   It is light years ahead of this old girl.

 Heath.jpg   388.5K   7 downloads

[snuff1966]

Absolutely brilliant stuff 

[76lxhatch]

Makes some nice noises

[LXCHEV]

Hey Heath - I'm curious about your latest concerns with the replacement starter. When you say it doesn't sound nice - are you referring to the starter itself turning over, or more the engagement/mesh of the starter into the flywheel? I know you did the 0.040" paper clip test (which should put it into the right window, which I believe is typically 0.025" - 0.060" or thereabouts), but maybe it still needs more/less to help with the pinion returning to the home position?

 

I fought similar issues for a long time on mine in the early days. I know SBC is different, but that mesh is so important if it's not right. I recall having broken starter pinion circlips, horrible mesh noises, chewed out driveplates x 2 (not nice when you have to mirror balance the replacement) etc. Eventually solved my problems by ditching aftermarket starters, and reverting to a cheaper factory style unit (combined with a quality driveplate).

 

Good luck. You don't want to be fighting starter problems long term.

[Heath]

Thank you guys.

 

BBQ-202 was the most simple car known to man, hahaha. Such an easy build compared to the hatch, and yeah, very different vehicle.

But through rose-tinted glasses, I will always miss and love the green machine.

 

Re: the starter, yeah, good question. So to me it sounded so awful like the gear was skipping over the top of my new ring gear, intermittently, during cranking.. I did in-fact add another shim when my friend suggested it, after I told him that it seemed mechanically loud, even though I should not have... that just made it run on the wrong part of the tooth.

 

Anyway, I had my mate look under the car while I cranked it and what's happening is that the starter is only running properly some of the time, and when it isn't, the motor's compression overcomes the starter and it spins backwards. THAT is when the sound gets really, awful.

https://www.youtube....rts/M47zP-dv8Cc

[Bigfella237]

Damn, that looks terrible.

 

When it spins backwards, is that momentarily releasing the key? Or does the starter just not have enough grunt to continue cranking the engine? Or is it possible that it's an ignition timing problem?

[Heath]

I think the starter maybe has a dodgy winding or brush and it's losing contact at certain rotational positions? (and presumably it's being driven backwards by the energy of the motor in compression at that point) I don't know how these things work.

I'm not releasing the key, and the ECU was powered down for this test, so there was no risk of injection or ignition corrupting the test.

[76lxhatch]

Bugger. Looks like there's at least 40 thou runout in the starter pinion too so going to be hard to get clearance right

[Heath]

My measurements actually suggested the flywheel/ring gear seems to have about .020" of run-out at least, which disappointed me. 

 

The video makes it look like the starter has a hell of a lot of run-out. I'm not sure if that's true or of it's just a bit loose and walks around a bit. I don't think either are awfully helpful.

[Toranamat69]

It doesn't look to crank very fast even when going the correct direction.

[Rockoz]

Check the voltage on the starter when you are cranking it.

As your battery is relocated, there may be a bigger voltage drop than anticipated.

That would explain the starter going backwards.

 

Cheers

 

Rob

[Heath]

It doesn't look like it's cranking very quickly because it's a mega slow motion video.

 

The cranking speed seems okay, like it did with the old starter, which makes me assume that this intermittent problem where it goes backwards is not related to voltage... am I being naive?

I should have checked the cranking voltage at the starter, but I did not when I had the people available.

[LXCHEV]

Quite interesting. I've experienced what I've called "kick-back" from time to time too when cranking my 383. Have never understood if this is voltage drop, engine compression over-coming the starter motor, or something else all-together. In my case, it doesn't produce bad noises or damage to teeth, so I just live with it. But I reckon it's probably doing something similar to you.

 

To answer your question - if it's cranking strong, it doesn't sound like voltage drop. Is it happening when both hot and cold?

[LXCHEV]

Here's some food for thought for you Heath: https://www.chevelle...ed-asap.220613/

Lots of talk around ignition timing during cranking (it's common for the Chev boys with high comp to retard timing during startup). Then there's talk of voltage drop / not enough current passing, also dying batteries get a mention, and too much fuel being in the chamber during cranking...

Edited by LXCHEV, 13 October 2022 - 01:19 PM.

[rexy]

I had all sorts of cranking problems with the old BBC in the ute.

To get the best engagement and cranking performance a relay was required.

The kickback was enough to pull teeth off the flexplate and break the nose off a starter.  This was cured with ignition retard on cranking.

 

Buy the best quality gear reduction starter you can.

 

 Holdens are usually stress free starters!

[Heath]

Wow, well I'm hoping I don't damage any more ring gears OR starters.

I would have bought a better "quality" starter motor if I could have found one the right shape/size. The Bosch units are NLA, and the other ones with the offset motors don't really fit.

 

Thanks for the link, Brett. Keep in mind, my ECU was off when I took that video, so I can't see it being affected by ignition timing or such. It was just cranking an air pump over.

 

I had barely driven the car, so can't comment on it hot vs. cold. Each time it made that awful noise, it was cold, because it sounded so awful that I just left the car running! Haha

 

I've been stressing about taking the car on a bit of a "test run" car camping at the Mt Tarrengower hillclimb this weekend, so I ordered another starter earlier in the week and put it in last night. Generally it sounds a bit healthier and it hasn't done the being driven backwards thing yet. Starts okay, and I'm gonna do a warranty claim on the old one. I balanced the throttles again after they went out of calibration during my dodgy dyno throttle linkage repair, and I've got the dash apart again due to the stereo power filter having the wrong wiring instructions, and me not fastening the headlight switch wiring connector well enough when I had the dash out the other day. Ooops!

 

Also vee'd out the join between the trumpets and the "clamps" (not being used as mechanical clamps any more, they just form the base that bolts down)

And fully welded. Bit of an ugly weld but it was just going to get ground down. Had to do it in a bunch of separate sections, cooling the trumpet in-between to preserve as much as I could of the black anodising.

[SHEEL]

that welding job looks very stress inducing!!!