Symphony of destruction

[rapidray]

As an engine builder I will tell all of you this: If you want to build your own engine, ALWAYS know the math on your engines! If you are having machine work done, ask QUESTIONS! Your machinist should give you EXACT numbers or he is a HACK!. Find a better machinist. And don't use too much timing advance! PERIOD! Ray.

[TheCafeKid]

I only remembered as I was writing the last response. We had put in regular once earlier but at higher altitude with no problems.

Ironically if we had been deep into the revs this might not have happened as we would have been well onto the mains.

Oi? Being high in the Revs doesnt mean your in the Mains...You can run the bike up to 9grand.. holding it there MIGHT NOT take being in the mains.... Mark off your throttle...you'd be surprised how LITTLE time you spend in the main jet...unless of course youre just racing the hell out of it from light to light.. *yawwwwn*

[Guest]

We spent alot of time at full throttle and I would not be suprised on the amount of time I spend on the needle circuit. That's what fried my motor again.

[49er]

We spent alot of time at full throttle and I would not be suprised on the amount of time I spend on the needle circuit. That's what fried my motor again.

You probably spend less time on the main jet than you realise, especially with your CV carbs.

I can certainly tell the difference of feel and response in the lower/mid range rpms between the VM carbs on the 850 and the CV's on the 1150. Sudden full throttle with VC's on a serious incline at say 3000 rpms, will only have the needle 1/3 out of the needle jet orifice for a short period. In the heat of the moment, a road rider often doesn't realise that. There is still a limit to that impressive torque of the big beasts. I notice this and the 1150 is still tuned to an airbox.

[TheCafeKid]

You probably spend less time on the main jet than you realise, especially with your CV carbs.

I can certainly tell the difference of feel and response in the lower/mid range rpms between the VM carbs on the 850 and the CV's on the 1150. Sudden full throttle with VC's on a serious incline at say 3000 rpms, will only have the needle 1/3 out of the needle jet orifice for a short period. In the heat of the moment, a road rider often doesn't realise that. There is still a limit to that impressive torque of the big beasts. I notice this and the 1150 is still tuned to an airbox.

uh heh heh heh, he said "orifice" huh huh uh huhhuhhuhuh

[49er]

uh heh heh heh, he said "orifice" huh huh uh huhhuhhuhuh

Yeah, how come that word slipped past the Administration Police???

[posplayr]

That drop in octane rating at the previous top up was "the straw that broke the camel's back". Leanness, high CR and poor quality gas looks the likely combination.

Glad you came clean with that last sentence. Confession is good for the soul!!

Spoke with Bill some more about this and it seems pretty clear he was running at an elevated CR due some combination of machine work milling the cylinders, head and the welding.

I might have been hitting 35-36 mpg at times and he hit 40 mpg which he never had previously done. We both previously would normally expect something like 32 mpg. So he was getting close to 15% better gas mileage than me.

Also at freeway speeds with roll on throttle he was getting some pinging and started running some octane booster from the beginning of the trip before we ever got to Fresno (less than 1Kft AGL and 100 miles from his house). This was even when using the 91 octane Premium. I though maybe he had some bad gas, so I grabbed a bottle as well but never used it. In fact I still had it at that last Ferndale fill-up. Maybe the reason I never heard it was because he had always added a good portion of octane booster; sometimes a full bottle.

The two times that we were forced to use Regular gas (Happy Camp and Ferndale), I was probably doing 50:50 mixes and never had any ill effects (pinging). I dont know haow much bosster he had to kick in at Happy Camp, but the last Ferndale fillup he added none. It seems clear that Bill's engine just could not survive the same octane gas as mine with what ever his higher CR was.

[first timer]

Time to carry a bottle of octane boost with you for just these occasions.

Bummer Bill really hate seeing those pics of you pistons... for a second time. Atleast now you have an excuse to go 1260.

[cruz del sur]

So sorry to see that happen to you Bill....

[rapidray]

DETONATION!!! TOO MUCH TIMING!!!!!! Ray.

[TheCafeKid]

You take a mortal man
And put him in control...

Watch him become a god!
Watch GS's heads a roll..

Just like the Pied Piper
Led Rats Through the streets
Dance like the marionettes
Swayin to the Symphony

OF DESTRUCTION...

[posplayr]

DETONATION!!! TOO MUCH TIMING!!!!!! Ray.

Ray we are both running stock timing after verifying the timing marks during the cam degreeing process.

[Guest]

You take a mortal man
And put him in control...

Watch him become a god!
Watch GS's heads a roll..

Just like the Pied Piper
Led Rats Through the streets
Dance like the marionettes
Swayin to the Symphony

OF DESTRUCTION...

I knew that was coming. I figured it would be you too.

[Guest]

Time to carry a bottle of octane boost with you for just these occasions.

Bummer Bill really hate seeing those pics of you pistons... for a second time. Atleast now you have an excuse to go 1260.

I have a 1230 kit. My buddy has the 1150 crank I need to purchase.

[49er]

Ray we are both running stock timing after verifying the timing marks during the cam degreeing process.

Ray is right. What he is saying is that Bill was running too much timing for the elevated CR with that modded head. The lower octane fuel you used, just lit the fuse.

You've really got serious timing issues when an engine starts pinging at low rpms and low loads. The safe option is to park it up until you address the problem.

I can sympathise with Bill. I made the same bad decision on one of my early rally cars. I was having gasket sealing issues after aggressive over boring. I milled some more ali off the head surface the night before a big event. I didn't have time to recheck the chamber volumes and just buttoned it up. I only managed to complete the first 8 kms before heat and detonation bought me to a halt. I later checked the volumes and found I was running 11.5-1 and trying to do it on pump gas and a bath tub chambered engine!!

The school of hard knocks is a great education tool, but it can make a serious dent in the wallet!