738 replies to this topic

[Bruiser]

It’s pretty weird that all 3 of you are having the same problem at the same time
Was it all ok during the real hot spell we had a couple of weeks ago?
Perhaps the extra compression you picked up with the small chamber head
means you are right on the edge of needing to run on 95.
9.9:1 is pretty decent for that cam
You could try pulling the timing back a degree or 2, would help the pinging
and slow the idle a bit too which might fix the deiselling.
Worth a try, anyway, can always be put back if you take note where it is now
Seems a shame to mess with the tune seeing as you just paid for a dyno session
unless they didn’t get into sorting the fuel and timing thoroughly enough?
Could give them a call and see what they can do.
What do the plugs look like now?
I think too rich (and/or too lean) can make for high combustion chamber temps
which has a part in deiselling too. Fact-check me here
Not too hard to experiment with the SU mixtures either, could try giving them a 1 flat tweak
Rich, and then lean to see if it helps at all. Don’t forget to take note of where you started again though
All just thinking out loud here, Warren might be right about the fuel

Maybe they’ve watered it down for the long weekend - (even race fuel??)

[S pack]

It’s pretty weird that all 3 of you are having the same problem at the same time
Was it all ok during the real hot spell we had a couple of weeks ago?
Perhaps the extra compression you picked up with the small chamber head
means you are right on the edge of needing to run on 95.
9.9:1 is pretty decent for that cam
You could try pulling the timing back a degree or 2, would help the pinging
and slow the idle a bit too which might fix the deiselling.
Worth a try, anyway, can always be put back if you take note where it is now
Seems a shame to mess with the tune seeing as you just paid for a dyno session
unless they didn’t get into sorting the fuel and timing thoroughly enough?
Could give them a call and see what they can do.
What do the plugs look like now?
I think too rich (and/or too lean) can make for high combustion chamber temps
which has a part in deiselling too. Fact-check me here
Not too hard to experiment with the SU mixtures either, could try giving them a 1 flat tweak
Rich, and then lean to see if it helps at all. Don’t forget to take note of where you started again though
All just thinking out loud here, Warren might be right about the fuel

Maybe they’ve watered it down for the long weekend - (even race fuel??)

Hey Bruce, TMK, lean mixtures are more likely to cause higher cylinder temps and dieseling.
 

[Bruiser]

Cheers, Dave

[claysummers]

Thanks fellas. Thought about trying E10 but unsure if it is safe.

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[yel327]

Probably not ideal with a steel tank, unless you have put a KBS kit through it. Probably wouldn't hurt to give it 20L and give it a blast then fill back up with 98 and run that through.

[claysummers]

Ah, yes. It’s hygroscopic! It’s so dry here currently, now would have been a good time, but the tank is near full and showers tomorrow?


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[claysummers]

Pulled this dissy from an injected black motor.

GMH pn 22017790. Bosch numbers on it also.

From my measurements it only seems to have like 12 degrees of mechanical and 6 vacuum. Can't be right?https://uploads.tapa...d698fc280f.jpg]

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[IMG]https://uploads.tapa...07addf1a5a1.jpg

Edited by claysummers, 04 April 2024 - 07:02 PM.

[claysummers]

WTF?
Photos

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[Dr Terry]

Pulled this dissy from an injected black motor.

GMH pn 22017790. Bosch numbers on it also.

From my measurements it only seems to have like 12 degrees of mechanical and 6 vacuum. Can't be right?https://uploads.tapa...d698fc280f.jpg]

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[IMG]https://uploads.tapa...07addf1a5a1.jpg

Yes, but they are "distributor degrees" they need to be doubled to become "engine degrees".

 

So, 24 deg mechanical, plus 12 deg of vacuum, plus 10 deg initial timing would be about right.

 

Dr Terry

[yel327]

9230064720 is a proper VK EFI dizzy. Specs are:

 

Centrifugal starts 1200-1300.

9-13deg at 2000-2100.

16-20 maximum at 5000.

 

Vacuum starts at 140-200mm Hg.

Finishes at 300-370mm Hg.

Max vacuum advance 11-15deg.

 

Total advance 27-35 deg.

 

It is a very different advance curve to the VH carby engines.

[claysummers]

Ah-ha! Thank you Dr Terry. Makes sense now. This should enable me to give it a bit more initial and less total.


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Thanks for the specs Byron


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[Bruiser]

Did you find an answer to all your deiselling and pinging problems, Clay?

[claysummers]

I think the dieselling was down to over fuelling of centre carb, sorted by adjusting float height thanks Bruce. Still a slight ping audible 3/4 throttle up hill 1800rpm plus. I probably shouldn't be pushing it under load at those revs in any case. This dissy should sort the issue, when I get around to swapping it over.

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[claysummers]

Bit of elbow grease should add a couple of HP

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[claysummers]

Now I've got the brakes operational, I've been able to do a test run with the new dissy. I set initial timing at +10. The pinging at 1500 - 2000rpm has gone, but off idle it will give one loud ping if taxed. I will back it off to +8 and play some more.

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[claysummers]

Backed off to +6 initial and still pinging below 1000rpm when severely taxed. The tank is low so I will try some fresh 91, but it looks like I may need to try 95 or 98. I heard the 98 octane rating degrades over a week.

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[warrenm]

Forget about 91, it's only good for your lawn mower. 95 or 98, I use 98 as I have 10.8:1 comp never had issues & use little fuel, it'll b

[claysummers]

Forget about 91, it's only good for your lawn mower. 95 or 98, I use 98 as I have 10.8:1 comp never had issues & use little fuel, it'll b

Yes, I will more than likely end up on higher octane, but I will try half a tank of 91 first.

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[Rockoz]

I stopped using anything but 98 in anything I own that runs on petrol a long time ago.

Started when I spent a lot of time trying to get a whipper snipper going.

Turns out before we had E type fuels one of the local servos was doing his own formula.

Took the snipper to mates workshop and he mentioned how many small engines were coming in with dramas and that fuel was the issue.

Changed the fuel and it started first pull. My shoulder was happy.

 

I was commuting from Wollongong to Singleton weekly for a period and did back to back tests on fuel in 2 different cars.

Although 98 was more expensive to purchase, it worked out cheaper in the long run to use 98.

 

With my VE SS at the end, I would fill up on 98 before leaving Wollongong, do the return trip as well as the commutes to site, plus running around between swings on a single tank.

 

On 95, I filled up in Wollongong and was near empty at Liverpool on the way home. Used around 1/4 of a tank more than the 98.

 

Since then I havent bothered with anything other than 98 unless I am near empty and nothing else is available. Then I just put in enough to make sure I can get to a 98 supply.

 

Cheers

 

Rob

[claysummers]

I did the economy test when I had the low comp head and twin strommies on this motor. Willunga Echuca on 98 and return on 91. Consumption numbers were identical to 0.1mpg. The computer and knock sensors on a modern car enable you to make use of the higher rating to sharpen the tune on the fly, which is pretty handy stuff. It means you can still safely run on fuel with a lower octane than optimal for your engine.

But there are no more calories in higher octane fuel, so you can't benefit from more octane than the tune requires. They are all the same fuel with or without certain additives. The octane boosting additives seem to deteriorate entirely over weeks as well, so if you fill up with 98 and don't drive for two weeks you now have a tank of 95 or even 91. Fuel stabiliser additives may alleviate this and I will definitely be giving this a try.

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[yel327]

E10 or 98 or 95. Made no difference to my Hilux or my Ram. Same economy for normal city and highway driving. I run 98 when loading them up aka towing as under load it gets you away from detonation. Ram wants 98 every few tanks as eventually it'll ping but I think that putting some fuel system additives would do similar - I think it's more the additives in the dearer fuels makes a difference rather than the octane rating, keeps the combustion chambers cleaner. Hilux had to have 98 once supercharged, but it had a detune switch that allowed it to run on E10 or 95 if it needed to. I never run 91, nothing seems to like it, even the mowers. The fuel degrades too quickly, I always add stabiliser to the Suzuki and to the cans for the mowers and only use 98 on those as by the time you finish it, the fuel is probably only as good as 91 anyway. I often reckon the times I get bad detonation in the Ram on any fuel, even had it on 98, is when the fuel is stale. High volume outlets like Costco I don't seem to have issues, but if I buy fuel from country towns it might be stale?

[claysummers]

Since the dissy change, I've been experiencing bad pinging 1000 to 1300 RPM, as well as occasional spluttering or missfiring 1/4 throttle 2000rpm. I put 98 plus this:With no difference.

Plugs, rotor, cap, leads look good and timing seems correct, +6 initial, mechanical cutting in about 1250rpm, maxing about +35 with a decent rev, not recorded but probably around 3500 to 4000 at a guess. I just noticed that the rear header is still leaking. I have yo chase up a decent gasket. I don't like the one I got, which is quite minimalistic. I hear Rare Spares has an extractor type one, so I will grab one on Friday.

The distributor shaft appears to have excessive end float, which eables the dissy gear to ride u the ca gear, and I am wondering if this is causing the timing to advance when the engine is under load. I should have examined it more carefully before installing it. I've only got a Gregory's for the VH as reference but I should be able to resolve the end float or else reinstall the old dissy.

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[yel327]

Just checking and it might be a stupid question or I should remember. But do you have a HEI coil with 12V feed?
Incorrect/poor spark could cause the misfire and also pinging. It may not even be the coil or dizzy but a bad plug, incorrect gaps or even plugs too hot. Trying colder plugs might be worth a go?
I do remember having pinging issues on a triple SU HQ 202 also due to a vacuum leak on the runner next to an extractor leak.

[claysummers]

Fair question Byron. Coil and dissy are factory VK Electronic Injection 202. I’m pretty confident I’ve found the problem, being the excessive end float in the shaft. I just need to shim between the body and drive gear and get the lash to a few thou, and all should be good.


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[RallyRed]

Regarding the manifold gasket...the ducks guts are the ones HSD in Melbourne sell. Think they make them for 9 and 12  port and they are grey  motor guys as well. Cant beat those gaskets.