sCREamnClones
New member
I'm pretty sure that the ONLY place you'll 'see' a couple (2,3 or 5) grams make 'any' difference what so ever, will be in your pocket-book when you pay your bill!
Piston Rule
- Thread starter DirtRacer7
- Start date
You don't need a dyno to tell you the difference. Just your butt will tell you when it shakes your teeth out at a given rpm. I would think you would know this if you raced stock cars as you claim. As for as more power it won't make much difference, but it will live a lot longer when things are in balance for a given rpm range. Even on single cylinder engines I have had the driver tell me he feels the difference on engines that we are not allowed to balance.
sCREamnClones
New member
Again....the discussion is of 'grams', Not 'Oz's! NOBODY's butt will feel that either! If ur talk'n '227' grams, 'maybe' we can talk abt it!!
definitely not momentum.
now (IF) you were allowed to run a titanium wrist pin and a lighter piston wouldn't you think your rotating mass would run with less resistance .weight is horsepower no matter where its at whether its in the motor or in the seat. why do they give specs on rings? thinner lighter rings, less drag and a freer mass. one answer could be weight. Answer this, why is there a minimum weight on the valves? It's not rotating mass it just lightens up the valve train. I'll take a lighter piston, ring , pin and rod any day.
DynoDon
Moderator
I thought I was asking a simple question. The reason I ask the question was because when I was trying to get the retainer measurement thrown out of the rules due to the controversy with the .815, It was told to me that the rule needed to stay because of the weight of the retainer. My question was to that statement " show me a dyno that will show me a H.P. gain from a retainer that weighs slightly less than another being that there is hardly any weight to begin with. " That was the basis of my post. I can see it in an 8 cylinder engine but I want to know if there is a Dyno on the market that will show it in a small single cylinder engine. 60 years? You are telling your age. lol
on this I have to agree with you don (you to screamer!!)....when your talking about a 4, 6 or 8 piston engine, then weight of the rod/piston/wrist pin is VERY important. its necessary to balance the crank and pistons to each other to achieve that balance. when you have a single cylinder, I would think that balance wouldn't play AS IMPORTANT part....it's all still important, just not AS important. more important is getting the crank to slide through the oil (as in knife edging it) and making sure that the rod gets lubricated to prevent galling and worse, a very large and unwanted blow out! balancing the crank in a single cylinder engine can be a very helpful thing, but trying to balance a single piston/rod to the crank seems excessive. understanding this, I don't think that weight is going to play or be a factor. power is produced in the upper part of the engine and your using the bottom end to transmit the power produced to the clutch, to the gears, to the axle, to the ground...as we don't have a counterbalance shaft in these engines, you are already going to get vibrations, but I don't think it's going to be enough to rattle your back teeth!
balancing any engine regardless of 1 or 12 cylinders is a complicated and time consuming effort. at our level, with our engines, it could almost be counter productive. I didn't build my motors last season with any thoughts of balancing anything. I bought the part, slapped that puppy in and fired it up. didn't worry about shaken, rattlin or vibratin.....I was more worried about launching that stupid thing into outer space and taking my arm and other body parts along with it!! and I ain't found a track yet that don't vibrate the crap out of my backside.....either in a car or a kart!!!
like I said earlier....long as it goes round and round and up and down, I figure that I dun did gud!!! that is unless it makes the gawd aweful bangin noises........
just my thoughts!!
balancing any engine regardless of 1 or 12 cylinders is a complicated and time consuming effort. at our level, with our engines, it could almost be counter productive. I didn't build my motors last season with any thoughts of balancing anything. I bought the part, slapped that puppy in and fired it up. didn't worry about shaken, rattlin or vibratin.....I was more worried about launching that stupid thing into outer space and taking my arm and other body parts along with it!! and I ain't found a track yet that don't vibrate the crap out of my backside.....either in a car or a kart!!!
like I said earlier....long as it goes round and round and up and down, I figure that I dun did gud!!! that is unless it makes the gawd aweful bangin noises........
just my thoughts!!
I would agree that the lighter reciprocating mass of the lighter piston, rod and wrist pin would offer some sort of advantage over a heavier one, but when your talking about a few grams like i mentioned, the power improvement will hardly even be noticeable, whether you measure it with your butt or the dyno doesnt matter. Who is going to think that a hundredth of a hp is going to make the difference? For the kind of improvement your looking at gaining with the lighter components, its not even worth the time your wasting handpicking thru all the parts and weighing them to find the lightest. That is wasted time that would be better used on working your tires or making sure your chassis rolls freely and is setup right. Ill take tires and chassis setup over a hundredth or even a tenth of a hp any day of the week and twice on sundays lol
Don I know you probably have a bushel basket full of retainers in your shop. grab a hand full and run a comparison on weight and record their thickness. what is the difference in weight of the lash caps, tall vs short? I'm surprised there isn't a min weight on all these parts.
DynoDon
Moderator
Probably the direction we are going, it won't be long. There is no doubt that the engines that are out there for $1100.00 has the lightest of everything and a bunch of machine work in areas we don't even consider including parts!!! Did ya ever wonder just how many really legitimate light parts there are on the market? I have weighed several retainers ( I do not have the numbers in front of me ) but there was not enough difference that convinced me that we couldn't lift the measurement that we now have.
but, in all seriousness, isn't this getting too far down in the weeds? the difference in grams or micro grams on the lash cap? retainers are retainers are retainers....they don't produce any power or make a difference if you have one that is measured at .15 or .16....they hold the springs in place...nothing more, nothing less. the only thing that you have to concern yourself with when it comes to a retainer is that it's thick enough to hold the spring in place and that it hasn't worn to the point of failure.
sorry....I don't want to be the cause of or prolong a disagreement, but we should be more worried about whether a piston produced for our use has the necessary thickness on top so that it can withstand the chamber pressures without failure and that it's heavy enough so that the rod doesn't pull the dang wrist pin out! and trust me, when I was looking at buying a wiseco/billet rod combo, a very good friend showed me a piston that was one step away from a catastrophic failure....the wrist pin holes had elongated, cracked and where probably seconds away from failure.
sorry....I don't want to be the cause of or prolong a disagreement, but we should be more worried about whether a piston produced for our use has the necessary thickness on top so that it can withstand the chamber pressures without failure and that it's heavy enough so that the rod doesn't pull the dang wrist pin out! and trust me, when I was looking at buying a wiseco/billet rod combo, a very good friend showed me a piston that was one step away from a catastrophic failure....the wrist pin holes had elongated, cracked and where probably seconds away from failure.
Actually, different thickness retainers can help with getting your installed spring height within spec mikey
It always surprises me when so many will argue about 1or 2 oz of oil, ring tension, ring end gap, making horse power gains. Heck knife edge the crank that does not come any where near oil in a liquid form, all that has done is lighten the rotating mass. Weight savings no matter how miniscule add up. If you put enough effort into checking all parts there is a benefit, it is the accumulated effort, not saving .01 of a gram on the piston but the accumulation of savings that make the difference.
The difference between a good engine and a great engine is attention to detail.
The difference between a good engine and a great engine is attention to detail.
youngengines
Member
I have weighed several retainers, and lash caps with no big difference found. I haven't found any thing special between the casting numbers of the heads (according to the dyno) either. With clearances set up where I want them, carb tuned right, they all make roughly the same power, again ..my results.
youngengines....i trust your results and advise.... when it comes to building these things, i'm not even up to the amature level yet. this ast year was my first. we didn't loose an engine due to our building them. we had one with a cracked block that we didn't know about and i had the exhaust studs pull out of the head, but not a cause of workmanship.
youngengines
Member
Thanks, and keep up the good work too. Good luck on the upcoming season!!!