86mm Turbo Pistons For NA Motor

[GRUNTMAX]

Hi,
Oh well, I tried with the 1mm o/size valves, motor turned over OK whilst degreeing the exhaust. Then I went to do the intake, 98, oh, that a bit low, moved the roller cam chain sprocket in the slot, turned less than 360, and, oh shi*, stuck. Off with it's head, again. Ordered stock size valves, and an extra 0.76mm spring steel head gasket just in case that will reduce CR from 13:1 to 12:1.
No, I'm not changing the base gasket again, was enough drama getting all the rings in properly with the 86mm offset big block, and no, I ain't changing the pistons either. I'd like to try & stick to the 13:1 CR if possible, for the road with 68mm stroke 1580cc.

"What it is";
Ross Pistons 86mm (Turbo) Used As NA Pistons Clearance Info

Intake Valve Pocket Depth   : 3.81mm +
Piston Deck Height Clearance: 0.40mm +
Muzzys Head Gasket-Spring St: 0.75mm +
Total                      =: 4.96mm =
Web Cam Intake Valve Lift  -: 3.95mm -
Clearance                  =: 1.01mm =
1.27mm required
CHECK INTAKE VALVE HEAD DECK CLEARANCE AT LEAST 0.27mm

Exhaust Valve Pocket Depth    : 2.80mm +
Piston Deck Height Clearance  : 0.40mm +
Muzzys Head Gasket-Spring St: 0.75mm +
Total                                      =: 3.95mm =
Web Cam Exhaust Valve Lift  - : 3.78mm -
Clearance                               =: 0.17mm =
2.03mm required
CHECK EXHAUST VALVE HEAD DECK CLEARANCE AT LEAST 1.86mm

ABOVE WILL GIVE 13:1 CR

IF ADDING EXTRA 0.75mm MUZZYS SPRING STEEL HEAD GASKET--12:1 CR

INTAKE VALVE LESS THAN 0.48mm PROUD
EXHAUST VALVE HEAD DECK CLEARANCE 1.11mm

Minimum Valve To Piston Clearance

Min 0.050" (1.27mm) for Intake  @ 8 degrees ATDC

Min 0.080" (2.03mm) for Exhaust @ 8 degrees BTDC

Now, after reading "What it is" above, how much extra clearance will 8 degrees before & after TDC buy me ?????
Have re-cut the valve seats, 15 turns with Neway valve seat cutter as had 300 to 320 shims before with correct clearances.

This ain't easy you know, try doing it when ya have a drunk driver inflicted severe traumatic brain injury

[knecum]

What do you mean your not going to change this or that?  what if you have to or you'll have to change the whole motor when it blows up How do you know you have whatever valve to piston when it won't even turn over?

[sportbikeryder]

I don't even know what the question is really....

How far are the pistons in the hole?

If you are concerned about changing the base gasket, why in teh hell did you put 86mm pistons with offset bores in a motor. No offense, but you really shouldn't be messing with big boy motors if you aren't able or willing to change a base gasket. Changing a base gasket is probably one of the easiest things to do when building a motor.

When you are setting up a new configuration for the first time, I would do so without the rings installed on the pistons as well as with only light valve springs on the valves.

Also, on a new, unfamiliar configuration, only checking PTV clearance at 2 places is asking for trouble as well in my opinion.

[sportbikeryder]

Hi,
Oh well, I tried with the 1mm o/size valves, motor turned over OK whilst degreeing the exhaust. Then I went to do the intake, 98, oh, that a bit low, moved the roller cam chain sprocket in the slot, turned less than 360, and, oh shi*, stuck. Off with it's head, again. Ordered stock size valves, and an extra 0.76mm spring steel head gasket just in case that will reduce CR from 13:1 to 12:1.
No, I'm not changing the base gasket again, was enough drama getting all the rings in properly with the 86mm offset big block, and no, I ain't changing the pistons either. I'd like to try & stick to the 13:1 CR if possible, for the road with 68mm stroke 1580cc.

PLEASE tell me you did not put oversize valves in a head that was not machined for oversize valves. I really wouldn't think that would be a remotely feasible thought, but I cannot figure out why you mention you ordered stock size valves unless you were going to put stock size valves in the same location that you currently have +1mm valves.

[GRUNTMAX]

  Shock, horror. Yes, I put oversize valves in a head not machined for oversize valves. Was never told not to, I thought cutting the valve seats a bit would do it, but oviously not. Was OK when I had it set up for supercharged with 10:1 CR. But now am going for 13:1 CR NA with 395/378 cams. Would rather have the 13:1 than oversize valves anyway. That is why I have now ordered stock size valves, for more piston to valve clearance.
I've written the piston deck height clearance down 0.40mm.
Sorry, but changing a base gasket is a drama cause there is so little room between the cylinder bores. Already busted 2 x oil rings in previous on/offs. Last time was easier as used 4 x ring compressors at once. If you think 2 x spring steel 0.76mm head gaskets is a 100% no no, just tell me.

The calculations were done for TDC. I just wanted to know approximately how much extra clearance I would have at 8degrees ?

PS. Don't knock learning the hard way. I certainly am.
It's not really a (edited). It's only a motorcycle engine.

[knecum]

Your a hot mess! !!!    Its to much to try to help you.   THIS SHARK IS OUT.SORRY!!

[sportbikeryder]

Learning the hard way is not a problem. Trying to build an 86mm bore offset stroker motor with oversize valves that have stock size seats and not being able to get pistons into the cylinders isn't learning the hard way, it is just a bunch of messed up guesses that just aren't going to work together.


While it may work, two head gaskets will present quite alot of opportunity for leakage, as well as being more prone to failure due to having more area exposed to cylinder pressure. Changing the deck clearance with base gaskets is the way to do it. Your issue with installing the rings is the lack of sufficient taper at the bottom of the bores to allow the rings to enter the cylinders form the bore size.

Is the head at least ported?

[GRUNTMAX]

Your a hot mess! !!!    Its to much to try to help you.   THIS SHARK IS OUT.SORRY!!

Thanks for your kind help. At least I took your previous advise on the cams.
"A hot mess", yeah, I kind of know that. Been described as a lot worse over the past 5 years.
Sharks never used to worry me in my old job, just used to belt em in the guts with a pipe wrench

[GRUNTMAX]

Learning the hard way is not a problem. Trying to build an 86mm bore offset stroker motor with oversize valves that have stock size seats and not being able to get pistons into the cylinders isn't learning the hard way, it is just a bunch of messed up guesses that just aren't going to work together.


While it may work, two head gaskets will present quite alot of opportunity for leakage, as well as being more prone to failure due to having more area exposed to cylinder pressure. Changing the deck clearance with base gaskets is the way to do it. Your issue with installing the rings is the lack of sufficient taper at the bottom of the bores to allow the rings to enter the cylinders form the bore size.

Is the head at least ported?

No worries, advise taken. I'll save the 2nd head gasket for the Gen2 transplant victim or the next one. Yes the head is hand ported. All intake ports CC'd up at 152cc.
Just hope I'm OK with the 0.40mm deck height clearance with stock size valves. I have the Brocks valve clearance tool.

[GRUNTMAX]

Oh well, have just checked, have a 0.020" (0.508mm) unused base gasket here that will give a deck height clearance @ TDC of 0.91mm on top of the base gasket thats already on for a 11.97:1 CR.

0.91mm deck height clearance--- Enough valve clearance with stock size valves ???

0.40mm deck height clearance--- Enough valve clearance with stock size valves ???

Thanks

[knecum]

no offense you just got to much going on for me to give you help then something else is wrong and its broke or whatever!!   then you say well you told me to do this!!! you feel me??  I mean i could build it but I'M in N.J.

[GRUNTMAX]

No offence taken whatsoever. Your not the only one who advised me to go with that cam profile. You've been very helpful in the past, & I do appreciate it 
Oh well, looks like 12:1

[wildphil69]

Not to be an asshole or anything but dont you think its time to take it to a builder?

[Jay]

PLEASE tell me you did not put oversize valves in a head that was not machined for oversize valves. I really wouldn't think that would be a remotely feasible thought, but I cannot figure out why you mention you ordered stock size valves unless you were going to put stock size valves in the same location that you currently have +1mm valves.

Wow, I never would have thought of that. I thought I had seen everything.

[GRUNTMAX]

Not to be an asshole or anything but dont you think its time to take it to a builder?

Phil, the only assholes that really exist in this world are insurance company defense lawyers.
No. I don't like to incur debts.
Been reading my Racing Engine Builders Handbook again.
The good ol days;
http://www.youtube.com/watch?v=CfMdHEY9weU

Watch out for Sharks mate.
Sooner or later, I'll get it right. What do ya reckon;
11.97:1
 Intake Valve Pocket Depth     : 3.81mm +
Piston Deck Height Clearance  : 0.91mm +
Muzzys Head Gasket-Spring St: 0.75mm +
Total                                       =: 5.47mm =
Web Cam Intake Valve Lift      -: 3.95mm -
Clearance                               =: 1.52mm =
1.27mm required

Exhaust Valve Pocket Depth      : 2.80mm +
Piston Deck Height Clearance    : 0.91mm +
Muzzys Head Gasket-Spring St  : 0.75mm +
Total                                         =: 4.46mm =
Web Cam Exhaust Valve Lift      -: 3.78mm -
Clearance                                  =: 0.68mm =
2.03mm required
CHECK EXHAUST VALVE HEAD DECK CLEARANCE AT LEAST 1.35mm
 

[wildphil69]

Good Luck...i feel Debt in your future

[GRUNTMAX]

PLEASE tell me you did not put oversize valves in a head that was not machined for oversize valves. I really wouldn't think that would be a remotely feasible thought, but I cannot figure out why you mention you ordered stock size valves unless you were going to put stock size valves in the same location that you currently have +1mm valves.

Wow, I never would have thought of that. I thought I had seen everything.

Yes indeed, now you have seen everything
1mm oversize valves in a Gen2 head. No machining. Only done with Neway Valve Seat Cutter set.
Degreed up just fine with the 10:1 CR 

[GRUNTMAX]

Good Luck...i feel Debt in your future

Thanks Phil, your not very good at reading between the lines are ya, in fact, your absolutely wrong in regards to your future predictions 
http://www.youtube.com/watch?v=zV-RbmLc3Ss

.....and just to be sure, might even bung on a 0.010 copper base gasket to make up for the 14degrees & oversize valve pockets. 

[Jay]

PLEASE tell me you did not put oversize valves in a head that was not machined for oversize valves. I really wouldn't think that would be a remotely feasible thought, but I cannot figure out why you mention you ordered stock size valves unless you were going to put stock size valves in the same location that you currently have +1mm valves.

Wow, I never would have thought of that. I thought I had seen everything.

Yes indeed, now you have seen everything
1mm oversize valves in a Gen2 head. No machining. Only done with Neway Valve Seat Cutter set.
Degreed up just fine with the 10:1 CR 

I guess you now realize that putting a larger valve on a stock seat with stock size throat hasen't acomplished anything except having a heavier valve that will run into stuff.

Glad you were sharp enough to stop when the motor wouldn't turn over and took it apart to see what the problem was.  We have had customers that would push the bike and pop the clutch in gear to see if they could get it to turn over. 

[GRUNTMAX]

  Thanks Jay. I'm obviously not your only customer with a Severe Traumatic Brain Injury
Also what would of made a difference with the 10:1 CR for supercharging, is that it was set up with Gen1 Intake with offset cam pin for intake, and Gen2 Intake as exhaust. 107 n 109 lobe centres.
I like APE's Roller Cam Chain Conversion   

[GRUNTMAX]

  4th hit of the start button & 
Ran a bit hot at first, now OK. Just hope it doesn't blow up on the dyno 

[GRUNTMAX]

Oh well Next day, rode it the 20 miles home, dyno not available for a few days, so thought I'd take it back to the shed to fix a small oil leak. 10 miles, half way, changing up from 2nd to 3rd, motor stopped.     It had seized.  All that brain injured satisfaction had just gone down the drain.
A lot of bearing flecks in the oil drain off. So much for all those bearing clearance measurements. It did have all green main crank bearings.
See what it is when I rip it apart I guess.
Life's like that 

........bearings look OK
 
Time to rip it's head off ------- Again !
Learning the hard way 

[Competition CNC]

Wow.  I dont even know where to begin......

Its over whelming.....

[Penianator]

    not that your stupid....only smiley guy that points up. Lol

[GRUNTMAX]

Wow.  I dont even know where to begin......

Its over whelming.....

Look at it this way Jim,  as a Professional Engine builder, it can only increase your workload.