Ayesully810 Posted September 29, 2017 Report Share Posted September 29, 2017 (edited) I got a pair of pretty nice stock cylinders that I plan on using for my drag build this winter. I'm for sure using these cylinders no questions asked, but I'm trying to decide if I want to do a 4mil or 7 mil. I already have the person picked out for porting. What special things need to be done on a stock cyl setup to make the 7 mil work. I haven't researched it much. I'm assuming just as thick as you can go base gasket, obviously porting, trenched cases and cut domes for the 7 mil? Would like to learn. Edited September 29, 2017 by Ayesully810 Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted September 29, 2017 Report Share Posted September 29, 2017 Hit up Jesse. He is making some killer 7mil stock cyls. Quote Link to comment Share on other sites More sharing options...
JTmachining Posted September 29, 2017 Report Share Posted September 29, 2017 Let a legit builder do it all. I’ve had a 7mm stock cyl motor and a 68 bore cub both with LEDs. Stock cylinders take work to make powa and $. Save ur $ and do a cub or bigger 1 Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted September 29, 2017 Report Share Posted September 29, 2017 The only musts are virgin porting , if they've been grounded on already the timings might not work with the stroke. Its really pick your poison, I've got stock cylinder 4 mills running 6.2 in the 1/8 in uncut stock chassis and 7mills going faster. The 7 was definitely easier to get the numbers out of but for what it is 4 mills run hard. The only thing you have to consider is the crank is a cpl Hundo more. I use forged wsm crank webs and put all my own parts on it. They've been really holding up well but just like anything else its attention to detail on assembly 1 Quote Link to comment Share on other sites More sharing options...
Ayesully810 Posted September 30, 2017 Author Report Share Posted September 30, 2017 14 hours ago, sleeper06 said: The only musts are virgin porting , if they've been grounded on already the timings might not work with the stroke. Its really pick your poison, I've got stock cylinder 4 mills running 6.2 in the 1/8 in uncut stock chassis and 7mills going faster. The 7 was definitely easier to get the numbers out of but for what it is 4 mills run hard. The only thing you have to consider is the crank is a cpl Hundo more. I use forged wsm crank webs and put all my own parts on it. They've been really holding up well but just like anything else its attention to detail on assembly Carl i was hoping ud comment. Just so everyone knows carl is doing my build this winter. But yeah the cylinders that im sending to you are completely untouched as far as porting. I was considering the possibility of going 7mil but im leaning more towards 4 right now bc there will be a little less involved. Quote Link to comment Share on other sites More sharing options...
Strm Trpr Posted September 30, 2017 Report Share Posted September 30, 2017 If you have a good 4mil crank and all other supporting mods why not just build a 421 Serval? Best bang for the buck, hands down. Redline's Serval topend kit is only $1,450 and that includes free top case port matching. http://redlineracing.biz/shop/4-10mm-serval-cylinder-kits/ The above numbers are not what I expect to see if I strap my Duner to a chassis dyno, and I'm perfectly ok with that. Quote Link to comment Share on other sites More sharing options...
JTmachining Posted September 30, 2017 Report Share Posted September 30, 2017 If you have a good 4mil crank and all other supporting mods why not just build a 421 Serval? Best bang for the buck, hands down. Redline's Serval topend kit is only $1,450 and that includes free top case port matching.http://redlineracing.biz/shop/4-10mm-serval-cylinder-kits/ The above numbers are not what I expect to see if I strap my Duner to a chassis dyno, and I'm perfectly ok with that.Wrong cyl for drag racing Quote Link to comment Share on other sites More sharing options...
JUSTWANNARACE Posted September 30, 2017 Report Share Posted September 30, 2017 Not much more involved in doing a 7mm over a 4mm. Trench cases and cut domes (which you will have to cut domes for a 4mm also) jmo Quote Link to comment Share on other sites More sharing options...
Strm Trpr Posted September 30, 2017 Report Share Posted September 30, 2017 Wrong cyl for drag racing Yup, my bad!Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
RagunCajun Posted October 1, 2017 Report Share Posted October 1, 2017 19 hours ago, JTmachining said: Wrong cyl for drag racing After riding a cub and my serval, id prefer to drag race my serval. If i could only have a banshee with drag ported cylinders, i would not own a banshee. They arent wrong, they just arent IDEAL for some people's needs. Quote Link to comment Share on other sites More sharing options...
JTmachining Posted October 1, 2017 Report Share Posted October 1, 2017 After riding a cub and my serval, id prefer to drag race my serval. If i could only have a banshee with drag ported cylinders, i would not own a banshee. They arent wrong, they just arent IDEAL for some people's needs.OP is doing a drag bike. Serval isn’t a good option vs others Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted October 2, 2017 Report Share Posted October 2, 2017 If you can afford it, go 7 mill you won't regret it. The difference in price is the a cpl hundred dollars between crank n trenching. The feeling when you smoke a cub with stock cylinders is priceless Quote Link to comment Share on other sites More sharing options...
Ayesully810 Posted October 2, 2017 Author Report Share Posted October 2, 2017 (edited) Chris. I already have a 421 dune/ trail bike, my driveline setup on pump gas and stock carbs is quite satisfying. Im set on using these stock cyls.. Carl, looks like we might be going 7 mil then. Edited October 2, 2017 by Ayesully810 Quote Link to comment Share on other sites More sharing options...
SandSlingerOR Posted October 2, 2017 Report Share Posted October 2, 2017 7MIL is cool cause we don't see that everyday like the 4mil. Quote Link to comment Share on other sites More sharing options...
JTmachining Posted October 2, 2017 Report Share Posted October 2, 2017 Peeps only give props to a win. It doesn’t matter cyl or size. Go big and fuck stock cyls 1 1 Quote Link to comment Share on other sites More sharing options...
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