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Hi guys I'm new to this forum and help would be greatly appreciated, I currently have a 2001 S&S 113 evo witch is basically all factory S&S besides a Mikuni hsr45 carb and manifold. I currently have the engine torn down and am on the hunt for a set of high compression Pistons I have target ratio of 11.0:1+ . I plan on running an ev84 .640 lift camshaft with some head work as well. Could anyone point me in the right direction as to who to call or talk to ? I do realize this is a high rpm, large lift cam high rpm power is what I'm shooting for. Thanks guys!
 

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Venolia pistons will make up a pair to any ratio you want. The 640 is a decent cam, I use one in a 113 as well... if you really want some high end power, look at the 631 cam since you are buying pistons anyway, add about a +12cc dome if you have the 92cc heads that should be on the 113
 

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Venolia pistons will make up a pair to any ratio you want. The 640 is a decent cam, I use one in a 113 as well... if you really want some high end power, look at the 631 cam since you are buying pistons anyway, add about a +12cc dome if you have the 92cc heads that should be on the 113
Terry,

I was able to go from 10:8-1 on my S&S crate motor to 11:3-1 to run a Woods 9F cam with just headwork. Lower end and pistons are untouched. Is the domed piston a better route? I assumed Flatop Pistons were better for flame propagation. Then again, his motor's apart too..... Different methods same result I guess
 

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Basically the total chamber volume needs to drop to 86-88, (my bad on the +12cc above math error), to use the 631 cam.. I'm not familiar with the woods cams, they do not work with my builds. (Woods cams increase the lift and shorten + move the duration around to cause a compression increase in engines that do not have the compression to sustain the longer duration). Woods cams also lower the use able rpms, not by alot, but, if you notice woods cams win dyno shootouts, I don't see a lot winning national racing events, a couple hundred rpms on the track mean the difference between winning and losing, on a dyno where the hp is, isn't as important as having those extra useable, rpms. The s&s cams from 631 up as well as the Andrews from ev81 and up grinds win races.they are difficult to set up, but worth the trouble if you are a serious contender.
I do not like milling heads, or cylinders to raise compression, I use these to bring the assemblies into blueprint specs. If I gain a bit of compression, cool. The flame propogation issue is moot in a chamber that open, and a tiny dome won't matter, if it does, dual plug it, problem solved. Also the really large cams for large engines have a high, long period of overlap, milling moves the valves closer to the pistons,
Venoila pistons are not off the shelf, one size fits all, they are machined to your exact specs, provided by you, you specify what you want. About 2 weeks later, they arrive.. defiantly not cookie cutter pistons like so many on the market that come to mind. These pistons are works of art, if you've seen prepped and fitted as many pistons as I have, these are awesome.
 

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Yep terry they are the 92cc heads, I had a feeling I was going to need to order a custom set. I am going to be drag racing the bike. I am also not a fan of shaving the heads I've just never ordered custom Pistons before kinda need someone to hold my hand hahaha
 

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I've done that before, with a different carb. Is this going to be street and strip? If you have the room a set of B2 heads is the shizznit!!! They do not clear in stock frames though, bummer.
If you do this, you will have a monster 113... look at the 631 cam, it's a power producer. Also the Andrews ev81, 84.and maybe the 88. All do wondrous things with a high comp. 113.
I use the 640 in a street motor, it's not bad, the 631 is better, lol, more power and a few more rpms.
The venolia's only cost a out $100 more than stock.
They are an easy to work with company, and will help you through the ordering.. go as small an over bore as you can, I would go like .005 over max.
Do this engine right and have a monster, do it wrong and have a 1 run wonder.
Pm me for help if you need it.
 

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Nice to hear you are going to drag race your Harley.
What kind of bike, and any details would be great.
Are you going to run this on the street as well?

113" is a great all around EVO platform to work with. Depending on how hard core you want to go, and compression and heads used, you can go more radical on your cam profile as well.
 

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Thanks for the insite terry!! I taked to Ron at axtell yesterday he seemed to think we could use one of his Pistons to get the compression out of it. This will require machining the head for a twin cam style piston. Witch I'm ok with.I do agree with his theory on the dished piston to help with detonation and tuning. Thoughts?

Morris the bike is a 1998 flht I tore the whole thing down last winter and rebuilt it, prettied it up new bushings berings suspension wheels ect. Went to chain drive with a Barnett scorpion clutch ( witch I still don't think is 100% diled yet ) the transmission is stock other than a Andrews input shaft (see how it holds up) I will be riding this on the street. I'm never 2up and I don't ride it like a touring bike haha. I'm not looking for a tourqe monster I want her to make power to 6500-7000 rpm. And hey if she granades then we'll go back to the drawing board. Hahaha
 

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Thanks for the info terry much appreciated, what kind of numbers are you seeing ?
:corn:

I don't race but have friends who do. Nothing sounds finer than a hi compression big twin idling through drags or a 2:1 meg then WFO through the lights......

Watching where this goes.......
 

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And don't forget these! Or......really really respect your rev limiter

 

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Terry,

I was able to go from 10:8-1 on my S&S crate motor to 11:3-1 to run a Woods 9F cam with just headwork. Lower end and pistons are untouched. Is the domed piston a better route? I assumed Flatop Pistons were better for flame propagation. Then again, his motor's apart too..... Different methods same result I guess
Flat tops have better flame propagation. And detonate less, so you can run more spark advance. To get around that with big domes, you can fire slot them or run dual plugs.
 

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Well honestly Axtell makes great products, however, buy a piston that is wrong and modify it to work??? The balance will be off right off etc. I would use the venolia's, if I were doing a complete engine Axtell may be my source. In this case, I would not consider their pistons. For many reasons. There is 1 other manufacturer that will make the pisrons for you custom, the price is about $100 more than a stock set of S&s replacement flattops. I know a couple S&s techs, they, off the record, will recommend what I'm telling you, or they will recommend getting a set of their unfinished dome pistons and have them machined to your needs, it will cost more take longer, and be a total aggrivation.
A high compression 113 and larger only need about 25-28° advance, any more and the motor will be damaged at high rpms. Ask me how I know, lol. .flame propugation, yes, a concern, can be corrected with dual plug ignition, if it is a problemm, use the Pistons and the correct cam, I will give you a 95% chance there will be no issue. and pick up a couple extra ponies in the meantime, free.
Carrillo rods, nice on a dragster, the s&s rods will be plenty strong for what you are doing.
Pwmorris is a man to listen to in building large performance engines, he knows big engines, having said thwt, listen to those who's experience is limited to smaller motors, well, large engines are different, with different needs, listen to those who build the big ones if you are doing under 100", the small motor tech advice is useful.
Detonation can be controlled in the large high compression engines by choosing the correct camshaft, and the piston dome and chamber should be smooth as a babies butt, not a sharp edge, high spot, and should be mirror polished, this eleminates detonation sources, and reflects heat back into the chamber, i have found this extremely beneficial in very high performance engines.. since you will be on the street a lot I would not use the 631, or the Andrews 88.
You must remember, everyone who has or makes pistons will attempt to sell their products, they will have something they think they can make work, it will cost as much as the custom made for you engine pistons and take just as long...the operative words in this are, "we have something we think we can make work". Ehrn you hear that phrase, and have this as a last choice, nothing else will work, do it, when you can have the exact product you need made for the same price??? No brainer, to me. I have nothing to gain with my advice, the Axtell salesman, does.
Getting 11/11.5-1 compression, can be achieved, how, with a 92cc chamber, and dished piston, how? ? Oh yeah a thin gasket, and milling the heads, honestly ????
I would just buy the right pistons now. The Axtell salesman is trying to sell you a low compression kinda OK running motor, when you can have exactly what you want, with a phone call and supply the correct info.
He is trained to talk you into his product, and away from a credit over 11-1, because the majority of guys will buy the absolute wrong cam, and push the ccp past 250, it's just a cam change away from the right or wrong setup.
My 113 s&s evo has 11-1 compression, the stock .043 gaskets, the heads have not been milled, the cylinders just enough to insure perfect blueprint spec. I use a 640 cam, with 28° total timing arriving at 1800 rpms, single plug heads, with the compression release holes plugged, cylinder pressure is about 190, courtesy of the camshaft selection, is starts easily with a stock starter, and battery with heavier cables, and makes 137hp, I only know the hp, because so many of my customers wanted to see what my motor made compared to all their motors I had built for them, I had a dyno at the shop, I did not overuse it, lol. The exhaust system is a restriction to the rpm level it can attain, it does not have enough flow capacity for the 113 to run past 62-6300 rpms in 5th gear, I knew this going in, I was good with it, since I was not going to race this engine, u have another exhaust that will allow 7k, if I want/need it..
Don't make mistakes and bad choices right now, for the price of a pair of pistons, boring the cylinders .005" a set of gasket, and a cam, you will have a screaming 113" machine, that won't break, unless you over Rev it..make sure your ignition can be adjusted to 25-28 degrees advance at 2000 rpms, and you will have the bike most will wonder why it is quick.
This is all math, do it yourself, do not let a salesman do it for you, it will be spun to make their product the right one for your engine. Do the math.
OK I've just given out more info than I normally would on an open to the public forum, if you want anything further from me, PM me,,
Discussing is nice, sometimes helpful, but honestly ,the short list of big engine builders is about 5 on this forum, with another 5-6 that have incredible engine building knowledge, but limited to smaller engines from what I see, so enjoy, and I will help, but I'm finished in the open section, tricks of the trade kind of things. You may know someone with one of my engines, they just smile when someone wants details of their engine builds, lol
Anyway it goes you will have a pretty quick engine,. In building engines, there is no real right and wrong, there are only so many ways to arrive at the desired results, the more experienced builders have made the mistakes and successes and remembers both well.
Math is the answer
 

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Thanks for the knowledge infusion Terry. I enjoy technical info even though I only get 75% of it
 

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Well honestly Axtell makes great products, however, buy a piston that is wrong and modify it to work??? The balance will be off right off etc. I would use the venolia's, if I were doing a complete engine Axtell may be my source. In this case, I would not consider their pistons. For many reasons. There is 1 other manufacturer that will make the pisrons for you custom, the price is about $100 more than a stock set of S&s replacement flattops. I know a couple S&s techs, they, off the record, will recommend what I'm telling you, or they will recommend getting a set of their unfinished dome pistons and have them machined to your needs, it will cost more take longer, and be a total aggrivation.
A high compression 113 and larger only need about 25-28° advance, any more and the motor will be damaged at high rpms. Ask me how I know, lol. .flame propugation, yes, a concern, can be corrected with dual plug ignition, if it is a problemm, use the Pistons and the correct cam, I will give you a 95% chance there will be no issue. and pick up a couple extra ponies in the meantime, free.
Carrillo rods, nice on a dragster, the s&s rods will be plenty strong for what you are doing.
Pwmorris is a man to listen to in building large performance engines, he knows big engines, having said thwt, listen to those who's experience is limited to smaller motors, well, large engines are different, with different needs, listen to those who build the big ones if you are doing under 100", the small motor tech advice is useful.
Detonation can be controlled in the large high compression engines by choosing the correct camshaft, and the piston dome and chamber should be smooth as a babies butt, not a sharp edge, high spot, and should be mirror polished, this eleminates detonation sources, and reflects heat back into the chamber, i have found this extremely beneficial in very high performance engines.. since you will be on the street a lot I would not use the 631, or the Andrews 88.
You must remember, everyone who has or makes pistons will attempt to sell their products, they will have something they think they can make work, it will cost as much as the custom made for you engine pistons and take just as long...the operative words in this are, "we have something we think we can make work". Ehrn you hear that phrase, and have this as a last choice, nothing else will work, do it, when you can have the exact product you need made for the same price??? No brainer, to me. I have nothing to gain with my advice, the Axtell salesman, does.
Getting 11/11.5-1 compression, can be achieved, how, with a 92cc chamber, and dished piston, how? ? Oh yeah a thin gasket, and milling the heads, honestly ????
I would just buy the right pistons now. The Axtell salesman is trying to sell you a low compression kinda OK running motor, when you can have exactly what you want, with a phone call and supply the correct info.
He is trained to talk you into his product, and away from a credit over 11-1, because the majority of guys will buy the absolute wrong cam, and push the ccp past 250, it's just a cam change away from the right or wrong setup.
My 113 s&s evo has 11-1 compression, the stock .043 gaskets, the heads have not been milled, the cylinders just enough to insure perfect blueprint spec. I use a 640 cam, with 28° total timing arriving at 1800 rpms, single plug heads, with the compression release holes plugged, cylinder pressure is about 190, courtesy of the camshaft selection, is starts easily with a stock starter, and battery with heavier cables, and makes 137hp, I only know the hp, because so many of my customers wanted to see what my motor made compared to all their motors I had built for them, I had a dyno at the shop, I did not overuse it, lol. The exhaust system is a restriction to the rpm level it can attain, it does not have enough flow capacity for the 113 to run past 62-6300 rpms in 5th gear, I knew this going in, I was good with it, since I was not going to race this engine, u have another exhaust that will allow 7k, if I want/need it..
Don't make mistakes and bad choices right now, for the price of a pair of pistons, boring the cylinders .005" a set of gasket, and a cam, you will have a screaming 113" machine, that won't break, unless you over Rev it..make sure your ignition can be adjusted to 25-28 degrees advance at 2000 rpms, and you will have the bike most will wonder why it is quick.
This is all math, do it yourself, do not let a salesman do it for you, it will be spun to make their product the right one for your engine. Do the math.
OK I've just given out more info than I normally would on an open to the public forum, if you want anything further from me, PM me,,
Discussing is nice, sometimes helpful, but honestly ,the short list of big engine builders is about 5 on this forum, with another 5-6 that have incredible engine building knowledge, but limited to smaller engines from what I see, so enjoy, and I will help, but I'm finished in the open section, tricks of the trade kind of things. You may know someone with one of my engines, they just smile when someone wants details of their engine builds, lol
Anyway it goes you will have a pretty quick engine,. In building engines, there is no real right and wrong, there are only so many ways to arrive at the desired results, the more experienced builders have made the mistakes and successes and remembers both well.
Math is the answer
I know this thread is 5 years old but Terry where did you get your pistons for the 11.0-1 113" S+S build? Do you have a part number or a set for sale? Thanx in advance, Andy
 
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