40mm Motorbike carbs on a triton (2.6L Astron)

[Billsy]

hmm. yeah that could be an issue. but i guess you wouldnt know till you tried.
on the other hand, was welding up and machining back the cam out if the wuestion? may have to remove some head material to get the clearance, but ive seen it done on other engines.

[Superscan811]

on the other hand, was welding up and machining back the cam out if the wuestion?

Again, chased up that avenue but at $100 a lobe, it's a bit much..

Modifying the rockers or dropping the cam towers were the only "relatively inexpensive" options, and seeing that I can do the rockers myself, guess which option worked out the cheapest (excluding my time of course).

On that note, I started and finished boring and bushing the rockers today..



You can see the height difference where the rocker shaft goes through. As the top of the rocker is in compression and the webbing going over the top of the rocker bears most of that load, removing 3 mm from the top is do-able and relatively safe, I hope...

I've also left a pad that can be machined down to correctly space the rocker.



You can see from this picture how the bush has been moved straight up with respect to the tappet. That is required to ensure the rocker and tappet are parallel to the valve at 1/2 lift.



All I need now is for the 19mm reamer I bought a few weeks ago, to turn up.


Cheers.

[Superscan811]

Still no reamer. Priced one (not off Ebay) and they want over $100 +GST

Decided to install a Digital temp controller for the thermofan.

The mechanical one was never switching on and I found out why, its lowest setting is over 90ºc. With the digital one, I can set it between -50º to 110º and also set the hysteresis (difference between the temp it will switch on and off).

Very easy to program and the instructions are in ENGLISH not ENGRISH .

Temporarily mounted the unit in the engine bay, but will move it into the cabin when I decide to tidy up the wiring..


I glued the sensor to the inlet manifold, right near the thermostat housing.

Seems to work well.


Cheers.

[Superscan811]

Put the Triton on the Dyno today and it made a whopping 72.7kw at the wheels . That's around a 15% increase on a stock standard engine.

It was running way too rich. Wide Open Throttle and at 3000rpm, the air fuel ratio was around 13.4:1 which is perfect, but by 4000rpm it was 11.7:1, and at 5500rpm it was 10:1.

When I get the jetting right, I should be getting at least 80kw at the wheels. With only the carbs and ignition, on a 100% stock engine that has done 360,000 kilometers, that's not bad (oh, and getting much better fuel economy to boot)..



Cheers.

[InsaneTD]

Seriously considering trying to do this to my car. I'd love improved economy and improved power.

[efisig]

Was it at unigroup? My mate Ziggy there was telling me about a triton he worked on today and I thought it sounded like this one

[Superscan811]

Was it at unigroup? My mate Ziggy there was telling me about a triton he worked on today and I thought it sounded like this one

Yep.

[DriveBy]

Stirling work, can't wait to see this with the head work and tydying up all done! Bet there's going to be alot more than a 15% bump when you're done
Bottom end rebuild and balance later in the year??

[Superscan811]

Stirling work, can't wait to see this with the head work and tydying up all done! Bet there's going to be alot more than a 15% bump when you're done

The 15% increase is compared to a new engine. It was around 24% increase on the way this engine was running.
On my old Sigma wagon, with a standard bottom end and just a standard M7 head, with a mild cam, and approx 8.6:1CR, I had over 84kw at the wheels.
With a bit of luck, with the High Comp M8 head with approx 11:1CR, 100kw at the wheels should be achievable.

Time will tell.

Bottom end rebuild and balance later in the year??

I'm in the process of building a few High Comp engines and a turbo engine with all the goodies, forged rods and pistons, larger and lighter valves etc... etc...
The triton will become a useful tool to run them in, and as a good comparison to gauge the difference strengths of each engine.

It will be fun..




Cheers.

[A112H]

[Superscan811]

The 15% increase is compared to a new engine. It was around 24% increase on the way this engine was running.

Just went back over the standard engine specs in Redbook and according to them, the engine had only 79kw when new, not 85kw like the sigmas.

That means it was a full 24% increase, with no internal engine mods at all, just carbs and timing.

It also runs 8.8CR with the good flat top pistons (zero deck height ) so the new CR will be approx 11.5:1

Bit the bullet and bought a reamer so if tomorrow is fine (raining here atm) I should have the head on early next week.

Cheers.

[Scorpma82]

ur CR will make the car far more powerful...and it will have better fuel effeciency again

curious to see how much better the results are

[Superscan811]

curious to see how much better the results are

Me as well..

Well, it should be up and running tomorrow, removed the old head and it was in surprisingly good condition.

Very little carbon buildup, and the pistons are the same.


Hadn't touched either the head or pistons, that's how they were when I removed the head.

All the bores are good, no scores, and only a minor lip at the top.

The pistons, as you can see, are the "high comp" version, with the raised center section approx 0.4mm above deck.

Decided to also removed the silent shafts because their guides were all stuffed, back to the aluminium.

The new head on and cam degreed in. Set the tappets .002" less than the hot setting and will re-check once the new cam is properly bedded in.

Basically I just have to bolt in the radiator, fill it, crank the engine over until it has oil pressure, then it's time to bed in the cam. Once that is done, it's time to test the beast..


Cheers.

[DriveBy]

Did you tidy up the valve reliefs/mild port while it was off? be awesome to see what gains you net next

[Superscan811]

Did you tidy up the valve reliefs/mild port while it was off? be awesome to see what gains you net next

I'm using a M8 head that had a bit of work done to it.

Ported, OS valves and seats, Behive springs etc...


Just couldn't resist using my rocker cover



Seat of pants dyno says it's got a lot more go but I ran into a bit of a problem, it wouldn't rev past 6000rpm.

Found the problem.
The MegaJolt has a soft rev limiter setting I hadn't seen. It drops the advance to 0 100rpm before the set limit.

Will test it out tomorrow.


Cheers.

[geezer101]

Very nice Superscan. Numbers on a sheet of paper don't mean much, it's all about how it gets it to the ground. How's the initial throttle response?

[75glnt]

Haha! This. Is. Awesome!!! XD

[Superscan811]

Very nice Superscan.

Haha! This. Is. Awesome!!! XD

Thanks..

How's the initial throttle response?

FUN.. Needs a lot less pedal to maintain speed, approx 20% less.

The only down side is the change in induction noise. Sounds beefy but I liked the previous throaty sound more.

Hopefully I'll get a vid tomorrow and post it up. Let the people decide..

Cheers.

[yno26galant]

maddd im liking it

[Superscan811]

maddd im liking it

Me too..

Just a short vid to compare the noise


Cheers.

[75wagon]

[bruggz351]

x2

sounds noice

[geezer101]

It's got a 'euro-tuned' sound to it, like an old school M3 BMW. Sounds like it pulls hard and smooth Superscan

[A112H]

[Superscan811]

Thanks guys, appreciate the feedback..

It's got a 'euro-tuned' sound to it, like an old school M3 BMW. Sounds like it pulls hard and smooth Superscan

The video didn't pick it up too well but the exhaust has more of a crisp popping sound to it, which now drowns out the induction noise

Have some plans to improve that..

The fueling is getting a lot closer but it could still be better. Above 5000rpm at Wide Open Throttle, its' running 13:1 which is OK (13.5 is optimal) but by 6300rpm its down to 12:1, which is way to rich.

The main jets are currently 1.425mm but tomorrow the 1.35mm jets will be going in.

Cruising and light throttle, it's now running around 17:1 which again is very lean, but it's not getting any lean surge or missing so it should be fine to run at this.

On the last dyno run, the guy commented that the engine seemed to be able to handle the very lean condition on light throttle. This is what helped the improved fuel economy, even though it was running very rich at high RPM, WOT.

A bit more tinkering and hopefully get the water injection running before I dyno it next time, and lets' see what she makes.



Cheers.

[Superscan811]

I'm very happy with the air/fuel ratios currently, just wanting to dial in a bit more timing when I finish the Water Injection setup.
Currently WOT max advance is 26º and the ignition map is static above 40% throttle. Anything more and I get a lot of detonation...

20 second log of cruising at 100kph, on a flat section of road. My AFR's are around 17:1 with no issues.



This is a 10 second log of 2nd gear WOT run from 1700-6700rpm. AFR's ar a bit lean under 3500rpm but there is no detonation.

The rev limiter kicked in at 6700 (drops the timing back to 0º), hence the "blip at the top of the graph.

Another interesting thing to note is that the manifold vacuum at 6700 is greater than 95% atmosphere. This means that the carb/manifold setup is generating very little parasitic drag on the incoming air.

Will have to get it Dyno'd both before and after the water injection to see the differences.




Cheers.

[Superscan811]

MAJOR SETBACK on Wednesday night.

Was heading up north, just got to the end of the freeway, looked behind me and couldn't see a thing for the smoke.

Thought I had holed a piston or something similar. Ended up being No:2 exhaust valve guide doing a disappearing act.


Absolutely nothing there.

There was no damage to the bottom end at all. It looks like the guide fragmented and went through the exhaust. VERY LUCKY. Even the valve and seat are fine so the head is salvageable.

Thanks to the huge effort from one of the SG members, we were able to get the ute back up and going on Friday.

Currently the ute is running with the old standard head (with 2mm shaved off it) and the standard cam. There has been a very noticeable drop in power and it doesn't want to rev past 5800.

Looks like the High Compression engine now has high priority over the other jobs.




Cheers.

[geezer101]

Sorry to hear about that super - at least that black cloud had a silver lining and it hasn't damaged anything else in the process.

[75wagon]

Looks like the High Compression engine now has high priority over the other jobs.

Think of it as, you finally have some direction now on what is the fastest way forward.
Too many projects clouds ones judgement.

Just hurry up and get one car finished
All of these side projects are just keeping you further away from you're ultimate goal.
For a bloke who loves Scorpions I've never seen you in one yet

Dave...

[BAD-SIG]

If you ever decide to sell these motorbike carbie kits for Astron engines, let me know!