Topic: Terry's new new redneck K0 "Special"..........

[Terry in Australia]

That probably makes sense Trevor, but don't tell Grant Roff (Groff, Spannerman, et al) as he has a bee in his bonnet about 98 RON fuel being "Snake Oil" even after I wrote an article in AMCT a few years ago telling him how my fuel economy increased by around 10% simply by running 98 in my Triumph Rocket III, which he at the time agreed with, then changed his mind, apparently, when he started a new anti 98 rant a few months later.

I never pay that much attention to bike journo's anyway, he may have been a qualified bike mechanic 50 years ago, but he's more of a "Captain Google now", and lost me completely when someone complained about poor running with their CB750K7, and he suggested that they check the diaphragms? On a K7? D1ckhead.........

[PeWe]

Same with my car that was designed to use 98RON. Possible to use 95 with power decrease written on a sticker inside fuel refill hatch. Why buy the version with more power and reduce it?

I read several posts by people using same model of car and engine version with turbo. Fuel consumption increased with 95. Mostly commuter people that could measure very equal. The difference in the 5-10% range.

My car has modified program and must have 98RON to get the improved torque, hp. (Turbo can get higher boost)
I noticed lower consumption when I changed to Shell V-Power from Statoil 98 fuel 5 years ago. Especially city driving. Usually around 0.1L/10km less I can not explain. Refills over several years. Same use of the pedal

Everyone should try at least 2 tanks of higher octane to the SOHC bikes as a test. Not much more money.

[grcamna2]

That '98RON',does it work-out to the same 98 octane as required for very high compression engines ?
The fuel numbers here aren't that high:regular 87 octane and premium is mostly 91 octane.

[PeWe]

You need 93 in USA to compare 98 RON.
I guess Shell V-Power will work everywhere. It had 99+ before over here, reduced a few years ago to 98+.

From internet:
If a fuel is 98 RON then it will be 93 PON -> 93 PUMP
If a fuel is 95 RON and 87 MON then it will be 91 PON -> 91 PUMP.

Yes, too low octane in higher compression engines will harm it. Pinging, detonation.

I have never heard about damages caused by "too high" octane fuel, only opposite.

Modern high power engines have another design to use 95RON. Maybe chamber design?

[Terry in Australia]

Yep, I read an article on the way fuel octane rating is measured differently in different countries, so from memory, the lower numbers in the US equate to higher numbers in Oz? I don't know about Sweden but I'm gonna guess from Per's post, that it's the same as Oz Bill?  

[PeWe]

It would be nice if lots of CB guys all over the world could use Shell V-Power 2-3 tanks, then back to the old lower octane fuel and feel the difference.

I have learned that improvements can often be more obvious when going back to the old and feel the degradation.
In Europe RON, 95, 98 and 98+.
Shell V-power might have 100 somewhere, not in Sweden.

(E85 102-105 due to all ethanol)

I saw 100 RON in former Jugoslavia many years ago (80's). Maybe Italy too.

We had earlier (until the 80's if I remember correctly.)
Regular (93/94), Premium (96/97) och Super (99/100 octane RON).

[Trevor from Warragul]

I never pay that much attention to bike journo's anyway

I had a similar thing happen with Derek Pickard.  He was looking at the Mikuni carbies on my Morini 3 1/2.  I explained how I chose the Mikuni needle by comparing the physical dimensions with the Dellorto needle, until I had a really close match.  He then phaffed on about how that was very unscientific, and not the right way to do it, and couldn't possibly work.  I then gave the bike a very casual kick, it started, and settled to a steady low idle.  I put on my helmet, and rode away, revving the bike crisply through the gears...   

[Terry in Australia]

And while we're on the subject, today was a "bonus ride" day for me. My big boy left for Sydney at 0730, so the wife woke me up to say goodbye, and he was off up the highway.

That meant that the driveway was clear, I was sick of pulling apart my DT1 engine that was more rusty mud than it was usable parts for my RT3, so I decided a ride was in order.

DT1 engine 7 by Terry Prendergast, on Flickr

DT1 engine 4 by Terry Prendergast, on Flickr

Thinking about high octane for high compression engines, I read another article about adding a cupful of Acetone to a tank of gas to increase the octane by a few points. I tipped around 400ml into the full tank of 98, and while I didn't notice any real improvement, the bike did run very well.

Now as you all know, I can eat pies every day, but just for the sake of a change, I did a 150 miler to Yea, via Whittlesea, and Kinglake. There were heaps of bikes on the road, mostly Harleys and Adventure Bikes (you know, those big trail bikes that are never actually ridden off road?) and I got a lot of waves and nods, which was nice.

I stopped in Yea for lunch, and a disappointing repast it was, went to a "Charcoal Chicken" and didn't want to wait for something to be cooked, so had the only thing ready, the two oldest dim sims in Yea, or possibly Victoria, but it was nice sitting under a tree in the park watching all the bikes go past. I think there was an all female bike club in town, as just about every bike (Harleys, Sports Bikes, Cruisers, Adventure Bikes etc) was ridden by a girl. Not too hard on the eyes, even though they probably weren't that interested in guys..... I had a missed call from Spotty, who told me that the next time I'm in Kinglake I should stop at the gas station there, apparently they sell 105 RON fuel.

K0 Sunday 31 Jan 2021 3 by Terry Prendergast, on Flickr

K0 Sunday 31 Jan 2021 4 by Terry Prendergast, on Flickr

Back on the road again, I stopped for a pic from a spot I hadn't been near for many years. It's near a lookout, so while I was taking a pic of the old beast,

K0 Sunday 31 Jan 2021 9c by Terry Prendergast, on Flickr

A guy wandered over to admire my bike, and offered to take a pic of me with it. Why not?

Terry and K0 31 Jan 2021 by Terry Prendergast, on Flickr

I chatted to him for awhile, we didn't exchange names, but I'm pretty sure it was a guy called Bob Rosenthal, the current president of the BMW Club of Victoria. I've only met Bob once before, but he told me today that he has an S1000RR and a F750GS, and he looked familiar. Bob was a big time racer back in the day and a bike journalist, I really must go to more meetings....... 

The old beast has now done 952 miles, so I think it's time to drop the oil and filter, and hopefully very little metal will come out with the oil. So far, it's going great, I'm a happy boy.

K0 Sunday 31 Jan 2021 9e by Terry Prendergast, on Flickr

[grcamna2]

Terry,when Bob saw you with those red boots,did he think you were a 'hot shoe'/performance rider,rather than a former BMW 'Touring dude' ? 

[Terry in Australia]

Ha ha, he probably thought I got them from a man with no legs!

[PeWe]

I really miss rides just cruising around on nice roads, eat somemething.

Those boots to charm ladies!

Did you open the cases on this engine?
 An oil pan off and clean inside and pump restrainer might be actual too. Always fantastic feeling to open oil pan and find nothing!
Good fresh gasket does not need to be replaced.

[Alan F.]

Ha ha, he probably thought I got them from a man with no legs!

I've been thinking this all along!


Terry I'm very happy this bike has been such a success for you and such a joy to ride. It's certainly been inspiring and I want to thank you for having us all along.

I'm wondering, are there attributes of this bike that likely stem from the combination of parts you've used that could be applied to later bikes? The pistons you've used and the cam for instance? Are there other parts that seem to contribute to the 'extra fun nature' of this bike? Or is this just the nature of a K0 by design, and everything afterward grew differently? I'd like to hear your opinions.

Can these combinations have the same or similar effects on even an F2 or K8? Or am I going overboard?

[seanbarney41]

Yeah, I am thinking those domed pistons added a noticeable amount of power.  I have always been under the impression that improved performance was more affected by compression than displacement, to a certain point anyway.  Those pistons also would explain the bike's thirst for high octane.

[PeWe]

Try to convince you again about a compression test with those pistons.

Static compression vs cam overlap.
I guess closer to 200 PSI with those domes.
CB750 stock 140-150 PSI, right?

[Alan F.]

...I've never bothered to measure the compression, but the domes on the CB77 pistons were so high in the little K0 combustion chambers I was more worried that something was gonna hit... I didn't build this engine for performance, but I think a combination of the high comp pistons, the electronic ignition, the Delkevic pipe, and (possibly) a little more duration from the K0 cam has given it a little more "oomph" than another stock CB750 engine.

[BenelliSEI]

Terry.... You mention “time for an oil and filter change”. That’s when I appreciate the open filter cartridge on the CB750. I let it sit in a tray, on some paper towel overnight. If there is anything amiss, you can always spot the clues, deep in the paper folds! I’m sure you do the same.

For standard spin on filters, I have a cutting tool for removing the outer metal housing. But it’s a
messy, dangerous job! Sometimes the old designs are more useful.

[754]

Yeah, I always  run the oil over cardboard , then wipe out the filter housing,   and check for debris..
 So spin on  really is not a real advantage to me. . I think the fin canister or Smooth style is clean looking..

[Medyo Bastos]

Sometimes the old designs are more useful.

... and new is not always better!


Sent from my iPhone using Tapatalk

[Terry in Australia]

Thanks guys, I'll drop the oil and filter this week and see what I see, my oil drain pan is bright yellow, so if there's any metal in the oil I'll see it right away, and I'll take John's advice and cut open the filter for a look-see. I can't see the need to drop the pan, I built this engine from a pair of bare cases that I scrubbed until I could eat my dinner off them, and all the other big pieces had been vapor blasted, so unless somethings fallen out of the mechanical gubbins, I'm expecting the oil to still look nice and clean.

I can't remember whether I used Castrol 4T or Penrite motorcycle oil, but I've always been happy with Penrite, (Aussie oil company since the 1920's) so that's what'll be going back in it. I don't think my compression tester has an adapter small enough for a CB750, and those two middle cylinders are a pain to get to, so I don't think I'll bother, but Sean is correct, higher compression allows an engine to more efficiently burn the fuel/air mixture, giving it more BHP, providing you use a higher octane fuel, and you've got a nice fat blue spark to ignite it.

Installing those CB77 pistons was definitely a bonus, there's a company in Britain that makes 4th oversize (61mm) pistons for CB77's, so I may use another set in the next engine (the K1) if I don't go the big bore route.  

[grcamna2]

Terry,you got any pics of a container of Penrite motorcycle specific oil? I want to learn what goes into it and what rating it has;I may visit a person in AUS some day and take motorcycle trips,who know?

[Terry in Australia]

No worrries Bill, I'll take a pic later, and you're welcome to drop in and see me when you come to the magical land of Oz, for a tour on a CB250RS, perhaps? I've been doing more wheeling and dealing this morning, and a 1972 Suzuki 125 "Prospector" is headed my way in a couple of weeks, and the T350 tomorrow, geez, I'm becoming a real (2) stroker!

Ok, and after only 10 weeks or so, my K0 fuel cap and petcock have finally turned up! I've sort of fallen in love with my old faded original paint K0 tank though, so I might just install the fancy tank for some "centrefold bike porn", then put old faithful back on for future rides. Maybe the fancy tank can go on the K1? We'll see.........

K0 fuel cap and petcock by Terry Prendergast, on Flickr

[Trevor from Warragul]

I've started using Penrite, and it is an excellent oil.  I recently rebuilt the clutch on my wife's 2001 Honda VTR250, and filled it with Penrite MC-4ST V-Twin 20W-50 full synthetic.  The motor is noticeably quieter.  However, the same oil made my 1978 Honda CBX starter motor slip.  A quick change to Penrite MC-4ST premium mineral soon fixed that.  These oils are advertised as "full zinc" (exceeding 1200+ ppm levels), which is a definite plus.

[grcamna2]

I've started using Penrite, and it is an excellent oil.  I recently rebuilt the clutch on my wife's 2001 Honda VTR250, and filled it with Penrite MC-4ST V-Twin 20W-50 full synthetic.  The motor is noticeably quieter.  However, the same oil made my 1978 Honda CBX starter motor slip.  A quick change to Penrite MC-4ST premium mineral soon fixed that.  These oils are advertised as "full zinc" (exceeding 1200+ ppm levels), which is a definite plus.

That Penrite does sound like excellent motorcycle oil.I usually run Shell Rotella 15/40wt. pure dino truck oil as it has the Jaso MA2 additive and I can get a 4)qt. bottle for just shy of $15.I have also found Valvoline dino 4-stroke(Jaso MA2) 10/40wt. standard motorcycle oil in our big box store not far from me for just a bit less than $5 a qt.

[grcamna2]

No worrries Bill, I'll take a pic later, and you're welcome to drop in and see me when you come to the magical land of Oz, for a tour on a CB250RS, perhaps? I've been doing more wheeling and dealing this morning, and a 1972 Suzuki 125 "Prospector" is headed my way in a couple of weeks, and the T350 tomorrow, geez, I'm becoming a real (2) stroker!

Ok, and after only 10 weeks or so, my K0 fuel cap and petcock have finally turned up! I've sort of fallen in love with my old faded original paint K0 tank though, so I might just install the fancy tank for some "centrefold bike porn", then put old faithful back on for future rides. Maybe the fancy tank can go on the K1? We'll see.........

K0 fuel cap and petcock by Terry Prendergast, on Flickr

I would certainly make sure to meet you and your wife Terry if/when I visit Australia.
I would like to get a CB250RS if I could get it back here after a purchase/tour.

[PeWe]

The oil thing as my K6 got too.
Starter can slip but not the clutch despite high torque numbers.

Happened when mixing in 20W-60 Red Line synthetic I bought when we had >30C summer.
Starter motor the stronger CB900 DOHC might affect a little too.
After that I mixed various oils into my own brew. Red Line for the high amount of zinc.

Last change Eurol HD Synth oil.
I'll see if it will get some Red Line added. Depends on how gear box will feel like.