Whitbread Posted September 28, 2014 Report Share Posted September 28, 2014 Ok, so I just put a hole in my left piston today of my stock stroke 12+ port stock cylinders. Most likely developed an air leak as the right cylinder is perfect. Not going to rebuild them since I picked up a 4 mil t rex cylinder that is virgin ported with pv's. Right now I'm running 128/195 port timings with my not so stock cylinders and PT high revs. For now I'll be keeping the PT's with the Rex, eventually I will build a custom set of stainless pipes that corkscrew in front of the motor like the PT's do. I'm after as much low/mid power as I can get while still keeping enough top end to ruin the pride of any unsuspecting 4 pokes. I know these are old school and I should've bought a cheetah pv and sent it out, etc, etc. But I like a challenge so lets try to make this thing scream. I've searched and read all I can find on the rex setups, but there's hardly anything out there other than "send it to K&T". Looking at the ports, the transfers have great volume, but a non existent short turn radius since the sleeve forms the inside wall of the transfer. Other than some slight height adjustments, the exhaust port doesn't look like it needs any real work. The intake and boyesen ports are huge, I can't see any gains to be had there beyond just cleaning and radiusing. Since the transfers seem to need all the work, any tips specific to these cylinders? Any particular roof angle they seem to like? Is the 128-130* still a good transfer duration figure or do these cylinders like seem to like something different? Should the transfer opening times be staggered or all open at the same time? For exhaust port timing, I've read these need more duration to hit good numbers than cp cylinders. How high can you go on these before you kill the bottom end? Thanks for the tips everyone! Quote Link to comment Share on other sites More sharing options...
registered user Posted September 28, 2014 Report Share Posted September 28, 2014 (edited) do you know what the trex timings are or you havent checked yet ? widening the transfers is typically never a bad idea. alot of times you can squeek out alittle bit more width in the center of the two windows at the bridge area. usually get alittle bit more width at the rear wall of the rear port but youll probly have to recut the hook to your desired angle, assuming it has a hook but im sure it does. might be able to do alittle bit of work on the front port regarding the width. alot of this stuff you just have to take a look and make a judgement call of what you can and cant do. maybe theres not enough material in a certain area to do any grinding so just cross that bridge when you get there. i never dealt with trex cylinders before so i dont have specific info to them but alot of modifications work well across the board on other engines. staggering trans roofs works well on other engines. ive did it on a few hondas before. cant say for sure how well it would do on yours though. if nobody can say specifically if it works on the trex then you might have to just try it and see. when i port my stockers ill be doing a stagger. most likely with rears opening first. on the transfer roof upward angles, generally the front port should alsways have more up angle than the rear but since your tunells appear to be nearly straight up and then turn, alittle extra up angle on all the transfers should help reduce some of the sharp turn into the cylinder. do you know what the upward angles are as of right now ? on the exh i like to keep my aux windows a couple degrees below the main window Edited September 28, 2014 by registered user Quote Link to comment Share on other sites More sharing options...
Whitbread Posted September 28, 2014 Author Report Share Posted September 28, 2014 I got a 392 cheetah PV for sale already ported. If interested. Whole motor or just topend. Lmk Too late now, I probably need a 4 mil crank anyway. Expecting some piston chunks hurt it on the left side. do you know what the trex timings are or you havent checked yet ? widening the transfers is typically never a bad idea. alot of times you can squeek out alittle bit more width in the center of the two windows at the bridge area. usually get alittle bit more width at the rear wall of the rear port but youll probly have to recut the hook to your desired angle, assuming it has a hook but im sure it does. might be able to do alittle bit of work on the front port regarding the width. alot of this stuff you just have to take a look and make a judgement call of what you can and cant do. maybe theres not enough material in a certain area to do any grinding so just cross that bridge when you get there. i never dealt with trex cylinders before so i dont have specific info to them but alot of modifications work well across the board on other engines. staggering trans roofs works well on other engines. ive did it on a few hondas before. cant say for sure how well it would do on yours though. if nobody can say specifically if it works on the trex then you might have to just try it and see. when i port my stockers ill be doing a stagger. most likely with rears opening first. on the transfer roof upward angles, generally the front port should alsways have more up angle than the rear but since your tunells appear to be nearly straight up and then turn, alittle extra up angle on all the transfers should help reduce some of the sharp turn into the cylinder. do you know what the upward angles are as of right now ? on the exh i like to keep my aux windows a couple degrees below the main window Haven't been able to check port timings yet. I'll have the pistons on tuesday to play around and measure things. I've been reading and watching a bunch of stuff Arlen has put up over the years and I know he likes to stagger the transfers on his PV honda cylinders. Quote Link to comment Share on other sites More sharing options...
Toomey Man Posted September 28, 2014 Report Share Posted September 28, 2014 TDR can explain a lot about the trex cylinders for ya Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted September 28, 2014 Report Share Posted September 28, 2014 Dan lamey(lamely?) was at racers edge(like GM performance of DASA) and was all over these. He would be a good fella to call if you can find him. Eric at Empire too! Other then that Tony @ TDR is your best bet. Oh, Arlen @ LED did many of these back at LRD. Quote Link to comment Share on other sites More sharing options...
Whitbread Posted September 28, 2014 Author Report Share Posted September 28, 2014 Dan lamey(lamely?) was at racers edge(like GM performance of DASA) and was all over these. He would be a good fella to call if you can find him. Eric at Empire too! Other then that Tony @ TDR is your best bet. Oh, Arlen @ LED did many of these back at LRD. I tried asking Tony some technical questions when I bought the sleeve and pistons from him, but he wasn't really wanting to divulge much specifics. He offered he'd be happy to install the sleeve and port it though.... I'll try reaching out to Eric and Arlen. I googled around and found Dan Lamey still works at racers edge, I'll shoot him an email too. I was hoping some people on here would have messed with them and might have some specific pointers. I've got a perfectly balanced crank to run with this topend.. Appreciate the offer but I've already too many parts for the rex to just toss it. Since I'm not after 300' times, I got it for cheap enough and I'm sure it will be plenty for my needs. Quote Link to comment Share on other sites More sharing options...
registered user Posted September 28, 2014 Report Share Posted September 28, 2014 never understood people trying to keep secrets. you would think they might want to help someone trying to learn and give em a few pointers. maybe theyre scared someone will try to profit from their ideas but what they dont realize is with a few simple tools and a bit of knowledge it aint hard to copy someones work. you may not fully understand why things are the way they are but you dont need to understand it to copy it Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted September 28, 2014 Report Share Posted September 28, 2014 Well I kinda get where Tony is coming from. He's not keeping a secret to be an asshole. It's just how he happens to pay his bills, so it's probably not the best idea to give all the details. He is usually pretty helpful if you're buying stuff though, it just comes with it's limits. People call me all the time to look at their jobs, I get to the house and they are fucked up half way through and they want me to take an hour off from being paid doing production, so that I can drive an hour to their home to walk them through the job and then go home empty handed. So I get it. Matt, have you tried speaking with CamATV? Quote Link to comment Share on other sites More sharing options...
registered user Posted September 28, 2014 Report Share Posted September 28, 2014 (edited) if you wanted to profit from someone elses work, wouldnt you pay for the work then youll basically have a template you can copy a million times ? so it makes no sense to not give a guy a few pointers over the phone or through email. clearly whitbread has no interest in copying or profiting from this, other wise he would do like i said and pay for the cylinder work then copy it as many times as he wants Edited September 28, 2014 by registered user Quote Link to comment Share on other sites More sharing options...
Whitbread Posted October 1, 2014 Author Report Share Posted October 1, 2014 Now that the sleeve is out, we can get a really good rare look at the ports. Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted October 1, 2014 Report Share Posted October 1, 2014 (edited) Interesting...... Usually now would be the time to start tearing in to the transfers, but there's not really all that much to remove. Maybe get the roofs of them aimed at the center of the dome Edited October 1, 2014 by trickedcarbine Quote Link to comment Share on other sites More sharing options...
m671054 Posted October 1, 2014 Report Share Posted October 1, 2014 Time to weld up the wall to roof transition for a smoother hook. Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted October 3, 2014 Report Share Posted October 3, 2014 If you have someone weld material to them make sure they preheat material first and be careful with the heat the casting becomes pour us and will fail a pressure test Quote Link to comment Share on other sites More sharing options...
Whitbread Posted October 3, 2014 Author Report Share Posted October 3, 2014 I won't bother welding, I'll use Devcon aluminum epoxy. Way less of a pita. Going to try some things with these. I'll post up pics when I start playing with them. Just got some new 1/8" burrs from CC to use on these. Cutting Al with dull stuff sucks. Quote Link to comment Share on other sites More sharing options...
registered user Posted October 4, 2014 Report Share Posted October 4, 2014 (edited) if you havent already, i'd do a test run first with the devcon and see how it holds up to e85. wasnt that the fuel you was going to use ? i tested one of my epoxies in a cup of methanol and it went to shit fast. i know it doesnt actually get submerged in the engine but none the less it still sees the exposure. so i just did a worst case scenario test Edited October 4, 2014 by registered user Quote Link to comment Share on other sites More sharing options...
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