MXZX Posted December 21, 2007 Report Share Posted December 21, 2007 Ok guys, I need your help on this. I have a 98 banshee with T-5's, a cool head, and a K&N pod. I am going to rebuild the engine this spring and just have some ?'s. 1st: What compression PSI can I run on 91-93 pumpgas? 2nd: Should I bore it over .050 or leave it stock? but either way it is going to be ported. 3rd: Should I pull the crank out and get It trued? Currently I have 115/120 compression. Any help is much appriciated, Thanks. Quote Link to comment Share on other sites More sharing options...
theshee Posted December 21, 2007 Report Share Posted December 21, 2007 Get the crank welded, if you are porting the motor its cheap insurance. You will have to look your cylinders over to see if it needs bored or not, if its not wore, dont bore it. Also, maybe you have one, but get a timing plate if you done have one. Quote Link to comment Share on other sites More sharing options...
91banshee Posted December 21, 2007 Report Share Posted December 21, 2007 you can run up to 150 psi on 93 and be fine ,wether or not it needs to be bored depends on the cylinders condition , if its stock bore 64mm i would just bore it 020 64 50 , yea get the crank trued and welded for sure . what dome size is in your cool head now ? Quote Link to comment Share on other sites More sharing options...
MXZX Posted December 22, 2007 Author Report Share Posted December 22, 2007 (edited) you can run up to 150 psi on 93 and be fine ,wether or not it needs to be bored depends on the cylinders condition , if its stock bore 64mm i would just bore it 020 64 50 , yea get the crank trued and welded for sure . what dome size is in your cool head now ? I have no Idea what domes are in it now, I bought it the way it sits other than some cosmetics and removing the overflow bottle. I was thinking about boring it just for some extra power, I knew that I may need to bore it if the cylinders are a bit worn on. The pistons cost the same as regular bore, and boring costs me next to nothing. Also Is the 350 a sleve motor or a nikasil motor? I'll Look at the shee and see if it has a timing plate when I pull it apart. Edited December 22, 2007 by MXZX Quote Link to comment Share on other sites More sharing options...
Washburn Posted December 22, 2007 Report Share Posted December 22, 2007 I have no Idea what domes are in it now, I bought it the way it sits other than some cosmetics and removing the overflow bottle. I was thinking about boring it just for some extra power, I knew that I may need to bore it if the cylinders are a bit worn on. The pistons cost the same as regular bore, and boring costs me next to nothing. Also Is the 350 a sleve motor or a nikasil motor? I'll Look at the shee and see if it has a timing plate when I pull it apart. Boring your motor more than it needs is not going to give you any noticeable power gains it will just shorten the life of the cyls. Now Pipes and porting it is going to be your biggest power gain. 120psi is stock compression and is good there is no reason to dig into the motor unless you need more power and porting it will do that. You can have it ported to fit the pipes you have or you can really open it up, you can always get a 4mil or bigger crank and have you motor ported for that and it will scream. Depending on where you want your power and what gas you want to run you can get smaller domes for your coolhead and a timing advance with a Ricky Stator timing plate(35 BUCKS). Biggest bang for your buck. Im running 160 psi with 20cc domes and +4 timing advance and 93 octane is working well but anything above 160psi calls for race fuel. You can have nikasil plated cyls but it doesnt come that way stock. Quote Link to comment Share on other sites More sharing options...
MXZX Posted December 22, 2007 Author Report Share Posted December 22, 2007 So basically what u just told me is that a mopar 440 has no more power than a mopar 383? Boring makes power, I know that, which is why I am considering it. Stroking the motor will cost me alot more $. I will do my own porting because we do porting on snowmobile engines as a side job. I could probabally have a deck chop cheaper than I could buy domes. My main question is Should I just port, chop the head, and refresh the top end and seals. OR, Should I port it, Bore it, and Chop the head. If the cost difference is only going to be $50. After Hearing it Im going to send the crank out to get trued and welded. Here is what I came up with so far. Pistons No matter what size of pro-lites I buy: $82 complete with 2 pistons, pins, rings, and 2 caged bearings. Piston ceramic coating: $50 Full Gasket and seal Kit $50 Crank True and Weld: $40 Head Deck Chop or new domes: $50 Boring(If I decide to): $60 Porting: $Free Quote Link to comment Share on other sites More sharing options...
Michael Jackson Posted December 22, 2007 Report Share Posted December 22, 2007 not to sound like a dick but.... why ask questions when you dont wana listen to the honest answer? ive seen many people ask about boring their cylinderrs for more "power" and the answer is always the same.. waste of time, waste of money, only gona cut down on the life of your cylinders for maybe a couple hp..thats like my friend when he got his bored 20 over for cleanup and a new topend, he thought his banshee was a 370cc now, that was a good laugh Quote Link to comment Share on other sites More sharing options...
91banshee Posted December 22, 2007 Report Share Posted December 22, 2007 So basically what u just told me is that a mopar 440 has no more power than a mopar 383?Boring makes power, I know that, which is why I am considering it. Stroking the motor will cost me alot more $. I will do my own porting because we do porting on snowmobile engines as a side job. I could probabally have a deck chop cheaper than I could buy domes. My main question is Should I just port, chop the head, and refresh the top end and seals. OR, Should I port it, Bore it, and Chop the head. If the cost difference is only going to be $50. After Hearing it Im going to send the crank out to get trued and welded. Here is what I came up with so far. Pistons No matter what size of pro-lites I buy: $82 complete with 2 pistons, pins, rings, and 2 caged bearings. Piston ceramic coating: $50 Full Gasket and seal Kit $50 Crank True and Weld: $40 Head Deck Chop or new domes: $50 Boring(If I decide to): $60 Porting: $Free boring does not make any more power on something that small your talking about stock 347cc (cc) compared to mopar440 and 383 , boring a 347 out more than nessesary gona be pretty much the same amount of power just lost all your rebuilds later. Quote Link to comment Share on other sites More sharing options...
MXZX Posted December 22, 2007 Author Report Share Posted December 22, 2007 boring does not make any more power on something that small your talking about stock 347cc (cc) compared to mopar440 and 383 , boring a 347 out more than nessesary gona be pretty much the same amount of power just lost all your rebuilds later. Im just saying boring makes power. Which is why industries make different engine sizes. .050 will make the banshee into a 369. and I can go to a .060 but there needs to be a little room to play. Quote Link to comment Share on other sites More sharing options...
Michael Jackson Posted December 22, 2007 Report Share Posted December 22, 2007 .050 over will be a 361 Quote Link to comment Share on other sites More sharing options...
zach45 Posted December 22, 2007 Report Share Posted December 22, 2007 lol do what u want... but i rode a banshee bored .100 over and it wasent noticable to a stock bore... i would rather have a stock bore... Quote Link to comment Share on other sites More sharing options...
91banshee Posted December 22, 2007 Report Share Posted December 22, 2007 Im just saying boring makes power. Which is why industries make different engine sizes. .050 will make the banshee into a 369. and I can go to a .060 but there needs to be a little room to play. makes tiny tiny tiny power increse over stock bore on a banshee , air and fuel makes power porting (profesional) porting makes power . if it dosent need boreing dont bore if it needs it do your first bore likea 64.50 020 and go from there with mods , Quote Link to comment Share on other sites More sharing options...
zach45 Posted December 22, 2007 Report Share Posted December 22, 2007 makes tiny tiny tiny power increse over stock bore on a banshee , air and fuel makes power porting (profesional) porting makes power . if it dosent need boreing dont bore if it needs it do your first bore likea 64.50 020 and go from there with mods , there you go... if you bore .050 over you just about cut the life of those cylinder in half... Quote Link to comment Share on other sites More sharing options...
dajogejr Posted December 22, 2007 Report Share Posted December 22, 2007 So basically what u just told me is that a mopar 440 has no more power than a mopar 383?Boring makes power, I know that, which is why I am considering it. Stroking the motor will cost me alot more $. I will do my own porting because we do porting on snowmobile engines as a side job. I could probabally have a deck chop cheaper than I could buy domes. My main question is Should I just port, chop the head, and refresh the top end and seals. OR, Should I port it, Bore it, and Chop the head. If the cost difference is only going to be $50. After Hearing it Im going to send the crank out to get trued and welded. Here is what I came up with so far. Pistons No matter what size of pro-lites I buy: $82 complete with 2 pistons, pins, rings, and 2 caged bearings. Piston ceramic coating: $50 Full Gasket and seal Kit $50 Crank True and Weld: $40 Head Deck Chop or new domes: $50 Boring(If I decide to): $60 Porting: $Free On a small two stroke engine, you only bore it to the next size to keep it at clearance specs. if you're a snowmobile engine builder/porter, I'd expect you to know that... 30 to 50 cubic inches is a big difference compared to 15 to 20 ccs. Most places will port the cylinder first, then bore it. If you happen to slip and make a goof...nick the cylinder with the grinder, it'll come out with a fresh bore. ONLY bore it to where it needs to be for clearance. Your motor is not real worn...to be honest. If your motor was way low on compression, say under 105 lbs, a fresh motor would make a bigger difference, you're only 10 PSI or so, give or take, from bone stock fresh, new. 82 bucks for two pistons and all the hardware must be your cost, and you must buy a TON of them because dealer cost is usually 100 bucks to 110 on a set of the pistons and all that hardware.... They retail 155 to 180 for a set of those. And please do not ceramic coat them... it's a total waste of time if it even works for pistons bought not already molybendum (spelling?) coated.... Quote Link to comment Share on other sites More sharing options...
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