aliveagain
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posted September 17, 2006 10:52 AM
Detonation looks to be the culprate.Very small warpage on the head but a definate leakage between cylinders of flame travel.I can see on the head gasket where the water followed around the cylinder seal and then got in.I'll have to wait until Monday to see what Billy Carlquist can do.My spark plugs kept fouling out and I hope sealing between cylinders will aleviate that.
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krexken
Zone Head
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posted September 17, 2006 01:27 PM
I recently did a head gasket job on a dry shot assisted 1270. His was a victim of a bad chamber patch job and one too many stages of the juice. It also has the big assed studs with no neck down. Can't say I'm a big fan of them yet especially since they make it more difficult to pull the head with the motor in the bike. I torqued them to 55ft/lbs as per the seller. I've seen several big bore 12s missing pieces of the piston around the valve reliefs but it didn't seem to be hurting anything. Also common for the top ring to loosen up and the second ring to tighten up in the groove. Weird that you're experiencing detonation without the spray but it sounds like your compresson ratio is too high or you need to back off the timing or both. Or, as said above, bad injector or something else really weird. What kinda piston to head clearance you runnin?
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aliveagain
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posted September 17, 2006 05:39 PM
I have 40 thou.pth clearance.When I was having it mapped,he told me he thought it was starting to detonate in the midrange.At the time I had it set at 2* advanced,so I brought it back to stock setting.I really believe getting the gasket to seal right will solve thepreignition,fouled plugs and coolant leakage.Ok those with the big bores and stud kit,what torque range are you using?
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aliveagain
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posted September 18, 2006 02:24 PM
On further inspection ,it was confirmed that it was detonation.I was told not to run pump gas anymore.He recommended new rings and will deglaze the cylinders.Pressure test the valves for leakage and true up the head surface.I was shown where to look on the piston to see if the other pistons were starting to go(basically between the rings and valve reliefs).Showed me the 6 digit # to order the rings because they are not listed.Cometic is making 2 new head gaskets for me.I also replied on Entropy's post about using Tim Marren in Oxford Ct. 203- 267 -3835 to go over the fuel injectors.Hell of a day and learning curve.
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entropy
Moderator
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posted September 18, 2006 03:11 PM
AA: when they true up the head you may wanna think about adding a .005" copper base gasket to keep more or less the same quench. Just a thought.
Another guy with a science fair project, I love it! 
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aliveagain
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posted September 18, 2006 07:25 PM
entropy,what do you torque your head bolts to?
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entropy
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posted September 18, 2006 11:15 PM
quote:
entropy,what do you torque your head bolts to?
OEM bolts, round of 17ft-lb, then 43ft-lb (as per manual)
don't lose the faith, AA, you WILL solve this!
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Y2KZX12R
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posted September 19, 2006 03:52 AM
Pete, you might want to try using the stock head bolts and put a little moly paste between the head bold and washer so you get proper bolt stretch before reaching the recomended torque value. Lubing the bolts is very often overlooked by most people, and its very important. At least use some engine oil if you dont have any moly paste.
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entropy
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posted September 19, 2006 03:56 AM
yep,
LIGHTLY oil threads and moly grease on the bolt head & washer.
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aliveagain
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posted September 19, 2006 08:17 AM
I think last time I used assembly lube on everything before torqueingWhy abandon the cylinder studs now?Billy said it was the detonation that blew the head gasket.I must admit,it was alot harder to install the cylinder with the studs in.
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entropy
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posted September 19, 2006 08:43 AM
My question is: Why use the studs if the OEM bolts work just fine?
BUT, if you already are using studs and have good info on what tq it takes them to stretch the right amount, easiest to just keep using 'em, eh?
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aliveagain
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posted September 19, 2006 08:48 AM
Earlier in the year, I was chastized for using the bolts over and over again and was told it is weakening the casing threads every time I assemble and take apart the motor.
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entropy
Moderator
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posted September 19, 2006 08:51 AM
ah, so you bought studs instead of new OEM bolts.
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TRNorBRN6001
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posted September 19, 2006 09:25 AM
It would be nice if ARP made a run of head studds for the 12 like they do for the Busa.
Those crazy Busa guys have bolts/studds that torque down to 85 ft/lbs. Guess that should keep most any straight head/block on tight enough for most applications.
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aliveagain
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posted September 19, 2006 10:21 AM
When it was being explained to me how much pressure is built up during detonation,I wondered if that might be why the #3 rod snaps.Even the wrist pin seating was showing alot of wear.
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Y2KZX12R
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posted September 19, 2006 01:21 PM
Pete, the studs might not be the problem. But if this has happened 2 times and the block and head are true and you used a new gasket both times then it points to the studs.
Have you calculated your static compression exactly?
Bills right about detonation causing a spike in cylinder pressure. Instead of a nice burnning flame front traveling across the chamber, the air fuel charge "pops" as an entity quite often but not always before the piston is at tdc. So instead of a steady increase in chamber pressure as the charge gradually burns, it all burns in an instant and causes very high chamber pressure.
Not having seen the parts me self i'll assume you had detonation, and i'm sure Bill is right, he has seen the result of many, many detonated to death engines.
If you can give me a few numbers i can figure your static compression ratio for you.
Chamber volume (with the spark plug and valves your using now)
Head gasket (compressed thickness)
Deck height (with the block torqued down)
Piston dome volume. (usually a neg. number -3.8cc etc)
Stroke
Bore
The last two are the easy ones 
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aliveagain
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posted September 19, 2006 01:58 PM
It was also with pump gas which was causing the problem both times.The last time I had a piston that had marks just starting to show.First time was with the bolts and this time had the studs in.I don't know the differance between your motor and mine and why I need the go-go fuel and not pump.I wouldn't have a clue as to how to measure those stats altho ,I'm sure my brother does.
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osti33
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posted September 19, 2006 02:08 PM
 Edited By: osti33 on 19 Sep 2006 15:09
quote:
If you can give me a few numbers i can figure your static compression ratio for you.
Chamber volume (with the spark plug and valves your using now)
Head gasket (compressed thickness)
Deck height (with the block torqued down)
Piston dome volume. (usually a neg. number -3.8cc etc)
Stroke
Bore
The last two are the easy ones
That negative is critical!!
Ask me, and Y2KZX12R how I know. 
Thanks again. 
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Y2KZX12R
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posted September 19, 2006 05:14 PM
I run super from whome ever and I dont have any detonation problems with my 1375. But i'm also running about 13 to 1 not 13.5 to 1. We both have stock cams so cranking compression will be a tad higher.
Ryan, its easy to mix that up.... I still get confused. thats why its nice to have someone else to confer with. I call Bill on stuff I've done many times but havent done it in years and years.
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Y2KZX12R
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posted September 19, 2006 05:35 PM
Ryan, did you read (2-17) that i sent you?
http://powerlab.mech.okayama-u.ac.jp/~esd/comodia2001/2-17.pdf
You too Pete, It will help you understand how and why shit hits the fan when people dont have enough octane for a given engine setup.
Its the main reason I cringe and dont perpetuate the "low octane is better" stuff you hear. Ya know, the "use the lowest rated pump fuels for these bikes" stuff. I have seen alot of junk parts and engines from detonation. The problem is you will never hear detonation if you have an aftermarket pipe. It takes about 1-4 seconds of severe detonation and the whole engine is fucking junk. Mild detonation and you just have to overhaul the engine and spend money and time to fix it, if your lucky.
Anyway, theres more stuff here http://powerlab.mech.okayama-u.ac.jp/~esd/comodia2001/contents01.htm and theres books and alot of other stuff on the net about this stuff if you really want to make your brain hurt.
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osti33
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posted September 19, 2006 06:11 PM
quote:
Ryan, did you read (2-17) that i sent you?
http://powerlab.mech.okayama-u.ac.jp/~esd/comodia2001/2-17.pdf
You too Pete, It will help you understand how and why shit hits the fan when people dont have enough octane for a given engine setup.
Its the main reason I cringe and dont perpetuate the "low octane is better" stuff you hear. Ya know, the "use the lowest rated pump fuels for these bikes" stuff. I have seen alot of junk parts and engines from detonation. The problem is you will never hear detonation if you have an aftermarket pipe. It takes about 1-4 seconds of severe detonation and the whole engine is fucking junk. Mild detonation and you just have to overhaul the engine and spend money and time to fix it, if your lucky.
Anyway, theres more stuff here http://powerlab.mech.okayama-u.ac.jp/~esd/comodia2001/contents01.htm and theres books and alot of other stuff on the net about this stuff if you really want to make your brain hurt.
Jim,
Honestly I haven't done much other than glance at it. I haven't had time. It is on my list of things to do as soon as I get time. I hope to sit down and read it over the weekend. I will have to read it in the morning when I am fresh otherwise I will end up hurting my brain. lol.
Ryan
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ALIVEAGAIN
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posted September 20, 2006 05:24 AM
Twas a little over my head
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psycho1122
Pro
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posted September 20, 2006 06:54 AM
I also run 91 Pump Premium Fuel (Cheveron) on my 1270. Up to this point, with over 13,000 hard miles on this set up. I have not run into any detonation issues. I run +4 on a Muzzy advancer and No Base Gasket with the piston kit.
However, there are a couple things I did to help minimize the possibility of detonation:
-Tight quench area: .027
-I carved or "widdled" away at all the sharp points and edges on the JE's relief cut outs. Then I smoothed them out with some tootsie rolls.
-Next, I had the tops of the pistons (above the rings) bead blasted to give a "Teflon like" surface for carbon deposits to evenly build up on. This provides a thermal barrier.
-Finally, I ensure that my map is never over 13.2-1 A/F ratio.
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entropy
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posted September 23, 2006 10:31 AM
Pete,
I talked with the guy who does my dyno work about studs. That shop fields 2 mojo turbo busas (with studs) and they know motor work.
I told him of yr situation and he immediately said ditch the studs, go back to OEM. Apparently you have to be very careful with the tq on studs. They use REAL high numbers...
He said that incorrect (too low) tq on the studs would cause the head to "rattle" because they need to be stretched like an elastic in order to keep a constant pressure on the head gasket. It's not just the tq number, it's more the stretch which keeps the headgasket from leaking between cyl.
I don't know shit about this stuff; just passing on what I was told...
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Y2KZX12R
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posted September 23, 2006 04:59 PM
I agree 100% Karl.
Pete, I would use the stock bolts that you have on the shelf.
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