Unleaded Fuel

[trikesrule]

The greenies have struck and we now have to run unleaded fuels. This has led to a spate of blown head gaskets through out the field. Some guys have reduced compressions and accepted the drop in performance. Some have gone to using Ultimate with Octane Boosters. None have brought reliability back like we had when we could use Avgas with Tolulene etc. Suggestions Please.........trikes

[1200Datto27]

Do you have to run "Commercial" fuels? can you use race fuels? Martini Racing has some good mixes available in 102 and 110 octane that are CAMS legal. Otherwise I have good results (better than Avgas and any other pump fuel) running Optimax/V-max with Nulon Pro Strength Octane Booster.

[ian_w]

Sunoco do a good range of race fuels: http://www.sunocoinc.com/Site/Consumer/RaceFuels/

NASCAR are switching from Sunoco Supreme leaded to 260GTX unleaded in 2007. Octane number drops from 112 R+M/2 to 98. Apparently there are no problems, engines are 12:1 CR.

Instead of reducing CR why not back the ignition timing off a couple of degrees if you think you are getting detonation?

What type of engines are you talking about?

[trikesrule]

Engines are inline six running 13.4:1. Am using BP Ultimate (98) with Nulon Pro Strength Octane Booster. Last Friday we tested entire ignition system. Renewed coil, module, entire dizzy, 6 out of 7 leads and the wiring loom between coil to dizzy (it was hanging on by one strand) and replacd all plugs because they were fouled. Whats the best why to clean petrol fouled plugs? We can run after market fuels but getting it here in Tasmania is a problem. Ignition is set (on dyno) at 27 with a two degree margin. Total is 32 degrees and it's all in by 4000.....trikes

[Al Weyman]

Sod setting ignition on a dyno, I did that once and lunched a nice 400 SB Chevy

[Notso Swift]

See my post in you other thread, you know Trikes, you only ned to ask a question once

Only place in Tas to get good fuel is Devonport Performance Tyres & Fuels, run by Scott Kent (who's family happens to own the Mobil Distributorship)... they aren't cheap, 1200datto. Add 50% to mainland prices.

Best thing to do with fouled plugs is thow them away, because they are never the same. Some people heat them, some blast them, but for $10 each just put some new ones in, because, like I said, they are never the same.

[1200Datto27]

I never said that the fuels where cheap (though compared to the likes of ELF, they are), just that they are good. I have found that whilst you can cut corners and save yourself a few $ in fuel, how much does doing so cost you in engine damage?

[johnny yuma]

I assume you're running an HQ ? 14:1 was always the point at which you
might get fastest lap but the head gasket was likely to go.Maybe you've
been through the good luck......
Did you calculate the compression ratio by filling each combustion chamber
with oil and comparing it to the swept volume?
Depends how precise your measurements are,maybe your ratio is higher than
you think? Time for another head? When the old original 98 octane leaded
Super disappeared in Sydney at least 10 years ago,my bog standard 186
HT Kingswood pinged without cure on any new pump petrol available,and it
only had 8.8:1 compression.Never blew a gasket,though.It pinged much
more when it was hot-how's your cooling system?

[trikesrule]

Hey Johnny Not sure what and how our engine man measures cc but I trust him. This cars not a HQ but the little bit of info I've squeezed from people here and there has led me to model our engines after what the HQ' run. I've heard that the HQ top runners are O-Ringing the block and bumping the compression to 15+:1. This engine is in a pink Bomber here in Hobart. The cooling system is improving year in year out. Race temp is 145 to 165 depending on the laps. On the dyno hp goes away when the ol girl goes over 173. We run Water - Wetter it's great stuff and we gained 6hp at the R/W' just puting that in the radiator. I don't reckon I can justify another head to this teams owner at the moment. ?I'm pondering the merits of an O-Ringed head. If we have to buy in hi-octane race fuels O-Ringing the head may well be the way to go. What are your thoughts guys? Hey Al how did the dyno lunch your chev. I'm curious. We use dyno's to test things and to make sure the ol girl is right to go for the next meet........trikes

[johnny yuma]

Crikey trikes I know Sydney is not on the "mainland" but what is a pink Bomber?

When the head gaskets go, is it oil in the water,water in the oil,and watery gunk out the exhaust,or less symptoms? Might help in isolating the problem-although usually it's the dreaded "combination of factors"

In my experience if the blow is cooling system pressure it gets into the oil galleries and the combustion chamber. If its compression ratio driven I'm
not sure where or in what piston it's more likely to show up but you'd think
if all C/Rs were equal it would be almost random if as you say the cooling system is good.

[trikesrule]

Hi Johnny LOL Sorry a Bomber is a speedway class that has a passenger. It's a pretty big class nationally. Our car a VK Commodore is pinky/crimson. So you may see it from time to time in a mag. Last gasket blew on the manifold side straight out the side sort of between #1 and #2. Missed the water jacket altogether. That made me think it is a tension problem (new studs not cycled properly). What are your thoughts?.......trikes

[trikesrule]

Hey Johnny your HT probably only needed a new set of springs in the dizzy so it didn't advance up so quick. Did u try that?........trike

[Al Weyman]

Hey Al how did the dyno lunch your chev. I'm curious. We use dyno's to test things and to make sure the ol girl is right to go for the next meet........trikes

It was EDA's dyno and we were getting about 470bhp and a similar amount of torque and massive torque at about 2000rpm onwards, one of the guys suggested 'swinging' the dizzy to try to get more topend BHP, the owner warned against it, I did not listen and bang it detonated several pistons and that was it, a lesson learned.

Tell me more about this passenger race, I'm interested and I will tell you why. I have suggested here amoungst other places that to (A) share the expence, or (B) assist in getting a sponsor or (C) give your mechanic more involvement that prehaps we should look at taking co-drivers in race cars, call them spotters or what ever you like, they do it rallying (far more dangerous sport IMO, it claimed poor old Peter's life after years of circuit racing) and also in motorcycle and sidecar racing so why not for circuit racing saloons etc.

OK I will get me coat before the flack arrives! :-)

[R59]

Al, you obviously swung the dizzy to far and too fast, and probably at top end. There's not much point at doing it at any more revs than the mech advance hits peak (what ever that is with a MSD dizzy).

With my little 4 pot 1600cc vauxhall lumps, it was at around 4500rpm.

Now, when I went fully mapped, that's a different kettle of fish!!

The advance map looked like a mountain range!! Scary amounts of advance at times.

Al, without a lunatic in the chair, sidecar racing wouldn't make it past the first turn!!

If you look up Tom Delaney on google, there's a site that show's a painting of Tom racing at Brooklands with his mechanic alongside. Then an up-to-date shot of Tom at Silverstone, on his own. Both in the same Lea Francis Hyper.
And there's another character the racing world misses.

How times have changed.

Rob.

[johnny yuma]

trikes--ran the info about gasket blow between #1 and #2 past a couple of ex-racer-entrants at work.They found it unusual,but just shook their heads at 13.5:1 compression.One thought a minor loss of surface on the face of the block or head may be a factor, and had a surprising suggestion of a smear of araldite,or if deeply pitted hammer in some copper then araldite.
Has this motor blown the gasket in other ways ?

the old HT was a budget daily driver but I did have a spare dizzy floating around which I tried but it ran the same-and the pinging exactly coincided with the first fillup with non 98 octane leaded.

Sounds as though overheating of coolant not to blame,anyhow.

[trikesrule]

Hi Johnny The old araldite trick. Yea they tried that before I came along. (old school stuff that). Cured their problem I'm told. U see two seasons back they did gaskets left right and centre (yep that many). Last season in my first season we blew none (no araldite). There are better glues than araldite for gluing the head on thats for sure. I turned up to do the preseason thing and there's a new 12 port head held with head studs in place of ol Mr Reliable. The team owner lent last seasons head to one of his mates (now wasn't that nice of him) and he's blown a gasket at three out of four race meets so far. I'm not telling his mate ****. The engine builder is reading (and lol) this as I type. He's leaning toward a MLS gasket glued on with Hyloma, cycle the head studs correctly and back the timing off a bit more. I'll sort the fuel and the track set-up. We're racing new years Eve. My first car was a HT Ute, black, lowered, flaired guards, 14 x 9 up front 15 x 14 Mickey Thomsons on the rear. 327 chev coupled to the mandatory 9" and a Turbo 400. Pretty std stuff. Best it ran was 13.1 at Surfers Paradise Qld. Oh and in the right corner of the tail gate it had FORDS SUCK. lol.........trikes

[trikesrule]

Al Bombers are a full contact speedway class here in Australia. Safety Gear: The passenger has to have everything the driver has plus a couple of grab handles. Insurance / License is the same as the driver. In the car there is a white flag that must be secured and be in reach of either two people. This is used in the case of a injury to either person in the car in case of an accident. If this is waved the raced is red flagged / stop immediately. Simple and very popular. Oh and a inside mirror. .....trikes

[johnny yuma]

I've heard they don't make 12 port heads any more so hang on to it.
Are they rare in Tassie?

A mate at work owned "MR.JUCY" an orange XD Falcon with orange interior
[street registered] 351 lots of trick bits got it down to 12.1 at Eastern Creek,was hungry for 11s but it was stolen from his driveway silently in early hours and never seen again.As a Holden man I'd say that Ford didn't suck in fact it frightened me the way the acceleration never tapered off and everyone stared at you !! Never blew a head gasket either...

[trikesrule]

good bit of fun when their that quick Johnny. Sorry to hear about MR JUICY. Thats the pits man. Had my ute in 78-9. Was quick for it's day. Dad used to help me heaps. Had to get our last two 12 ports from the north island. Yep good low k ones are getting hard to find. I have one left........trikes