Free yellow banshee Posted October 31, 2013 Report Share Posted October 31, 2013 I have a stock stroke crank with ported cylinders. I am also running a cool head with 22cc domes. I want to put some 21cc domes in. I don't think the crank is welded and I have no idea how many hours are on it. My question is if I put a +4 crank in (with spacer plate) will it throw my port timing off? I know everybody is going to say get the cylinders ported again and get some custom cut domes. I really would rather not go through all that. It's a trail bike and I'm just looking for a little more bottom end. Also I want the piece of mind that a fresh bottom end will give me. I'm at sea level and haven't checked compression yet. Any ideas on the crank? Quote Link to comment Share on other sites More sharing options...
do-work-son Posted October 31, 2013 Report Share Posted October 31, 2013 Why not just send your crank out have it welded or put a stock stroke hot rods crank back in it for the piece of mind factor? Quote Link to comment Share on other sites More sharing options...
sprinklerman Posted October 31, 2013 Report Share Posted October 31, 2013 I have a stock stroke crank with ported cylinders. I am also running a cool head with 22cc domes. I want to put some 21cc domes in. I don't think the crank is welded and I have no idea how many hours are on it. My question is if I put a +4 crank in (with spacer plate) will it throw my port timing off? I know everybody is going to say get the cylinders ported again and get some custom cut domes. I really would rather not go through all that. It's a trail bike and I'm just looking for a little more bottom end. Also I want the piece of mind that a fresh bottom end will give me. I'm at sea level and haven't checked compression yet. Any ideas on the crank? ^^Trying to understand the logic here,, you say "I know everybody is going to say get the cylinders ported again and get some custom cut domes. I really would rather not go through all that."...... but you are still asking what we think ,,why? 99% of the people ( who know anything 1st hand) are going to say EXACTLY what you already know they are going to say. Does that answer your question? Not trying to be a butthole,but you really do already know whats going to be suggested..or are you hoping SOMEBODY will tell you what you want to hear? Like i said, just trying to understand the logic of your question. Quote Link to comment Share on other sites More sharing options...
Free yellow banshee Posted October 31, 2013 Author Report Share Posted October 31, 2013 ^^Trying to understand the logic here,, you say "I know everybody is going to say get the cylinders ported again and get some custom cut domes. I really would rather not go through all that."...... but you are still asking what we think ,,why? 99% of the people ( who know anything 1st hand) are going to say EXACTLY what you already know they are going to say. Does that answer your question? Not trying to be a butthole,but you really do already know whats going to be suggested..or are you hoping SOMEBODY will tell you what you want to hear? Like i said, just trying to understand the logic of your question. My main question is what will happen if I run the spacer plate? What effect will it have on the port timing? I understand that it will perform better if I get the cylinders ported again and get custom domes cut. If I run the spacer plate will it perform better than stock stroke? Would I see any increase in bottom end with the spacer plate? Quote Link to comment Share on other sites More sharing options...
Free yellow banshee Posted October 31, 2013 Author Report Share Posted October 31, 2013 To sum it up, would it be better to put a stock stroke crank in or run the spacer plate on the +4? Which will perform better? Quote Link to comment Share on other sites More sharing options...
sprinklerman Posted October 31, 2013 Report Share Posted October 31, 2013 Ahh,, that makes more sense. It will make the bikes powerband more narrow and pipey. Especially dependent on how much its ported now. Without knowing the port lay out now though, its still kind of a guess. You really need to know where its at now. Quote Link to comment Share on other sites More sharing options...
sprinklerman Posted October 31, 2013 Report Share Posted October 31, 2013 If you like the power it makes now, id stay stock stroke. Quote Link to comment Share on other sites More sharing options...
sheerider11 Posted October 31, 2013 Report Share Posted October 31, 2013 Don't bother. There's a right way and a wrong way. Guess which one cost more money. Quote Link to comment Share on other sites More sharing options...
Free yellow banshee Posted October 31, 2013 Author Report Share Posted October 31, 2013 ^^^ exactly. Well looks like I will be putting a stock stroke crank in then. I just hate replacing without upgrading. Quote Link to comment Share on other sites More sharing options...
KaN Powersports Posted October 31, 2013 Report Share Posted October 31, 2013 You could go the 'old school' long rod/blaster piston route and feel some gains, but like stated above, without knowing/or checking on porting, you are just "rolling the dice" Might have a favorible outcome, might be doing it again right after getting it running.... Quote Link to comment Share on other sites More sharing options...
Free yellow banshee Posted October 31, 2013 Author Report Share Posted October 31, 2013 So it looks like I will stay with stock stroke and up the compression some. Thanks guys. Quote Link to comment Share on other sites More sharing options...
sprinklerman Posted October 31, 2013 Report Share Posted October 31, 2013 You didn't mention what pipes you have. Different pipes could help you in the TQ department. Also if you were prepared to spend money on that 4mm spacer kit, why not take that money and have your cyls looked at and see if the porting can be improved upon for a small fee? Sent from my SCH-R970 using Tapatalk Quote Link to comment Share on other sites More sharing options...
Free yellow banshee Posted October 31, 2013 Author Report Share Posted October 31, 2013 Well I have t5 pipes. I am trying to trade them for 916's now. Not sure how much it would be to change the ports to match the 4mil crank. Basically I want a fresh welded crank so I can up the compression. I will look into changing the ports. Thanks for all your help. Quote Link to comment Share on other sites More sharing options...
sheerider11 Posted October 31, 2013 Report Share Posted October 31, 2013 Well I have t5 pipes. I am trying to trade them for 916's now. Not sure how much it would be to change the ports to match the 4mil crank. Basically I want a fresh welded crank so I can up the compression. I will look into changing the ports. Thanks for all your help.I went from porting to 4 mil porting by the same guy for 100, 80 for the domes. Quote Link to comment Share on other sites More sharing options...
Free yellow banshee Posted October 31, 2013 Author Report Share Posted October 31, 2013 Nice. Well I'll check it out. I have to build my other bike before I break this on down. Quote Link to comment Share on other sites More sharing options...
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