Now that I've got your attention, I've successfully removed the heads and on doing so found a peculiar sight. Now I'm no stranger to engine internals, been a mechanic for years. But I've seen something new today. Each piston, in the centre of it's crown, has a nipple sticking up about 3/8th of an inch and about 7/16th in diameter with a small recess in it's centre. What the doodadds is that all about ? The only thing I can deduce is that it aids 'swirl' as the incoming gas/air mixture enters the cylinder. Please put me in the picture oh wise ones. Looking forward to cracking off the manifold bolts tomorrow, maybe I should choose a better word than crack when I'm dealing with cast iron. O.k, I'm outta hear, got some beer to drink and good woman to erm...........................................................................
Those "nipples' that you call them are actually made to help promote the swirl combustion process.If you also notice,you have angled spark plugs.All Buick engines(with the exception of the Nailheads) have angled spark plugs.These are also designed to aid in producing a swirl effect thereby increasing horsepower.When you replace your pistons,you will not have these "nipples";you'll have valve reliefs instead.
I had always heard that those 'bosses' in the middle of the piston's top - were left there as a 'cost saving measure', since machining them down flush would have been one more machining step. The current TRW/SpeedPro/Sealed Power forged pistons have them removed. Seems like the 90* sharp edge on the boss 'might' be a 'hot spot' and a potential source of pre-ignition.o No: It would be nice if there were any swirl benefits though.
Does anyone know if these can be ground off with the pistons still installed? Or, is it best just to smooth them out with a die grinder?
Nipples Nipples? are we talking about the Janet Jackson Superbowl half time show?......ooops sorry, wrong thread ou:
Why grind them off? The only thing that will do is lower your compression. If you have to do a rebuild anyway,replace them with new pistons.
These are forged replacement pistons in a good engine. Grinding them off would eliminate hot spots and help eliminate detonation, I would think.
I've never seen these "nipples", anyone have a picture of em (not of janet jackson, I already have one of those :Brow: )?
NIPPLE SHOTS Careful what you ask for.....for you may surely get it:Brow: Miss Bowling Green 2003 has what you are looking for.... If this was'nt a "G" rated site I'd post her picture :grin: that was taken in the News Inn parking lot! Peace WildBill but she still don't beat the "Time Slip Girl" from a couple nats earlier
Something tells me the jewelry would create some pretty bad hotspots. So for the record, I recommend not putting jewelry on them!:shock:
always, after a long hard day, I can find something on this board to make me laugh. Keep it up.:grin:
what the heck have I started here? you lot are all barkin` mad, glad to hear it though. The motor has gone back together, should be startin it up soon. bye for now. Dave.
those "stars" really help create addtnl swirl. If properly attached they actually spin when the motor is running and add MASSIVE swirl and tumble to the mixture. Kind of like having a turbo for every cylinder! The "Jackson Swirl Inducer". Patton
