Tim_C. Posted March 26, 2002 Report Share Posted March 26, 2002 Hey guys, I just weighed my new pistons, and they are 130 grams ea. lighter than my .060 over hyper-u's were! That's a lot for you guys who don't know. These are .075 over too. I will even lose a tad more weight by putting the sleeves for the floaters in because they are bronze, and steel needs removed to fit them in. This type of piston weight reduction will gain RPM's much faster, and go higher more safely. Should be a big improvement on HP and Torque numbers. So, not only are they more of a bulletproof piston, but they are much lighter, and have an oil galley from the oil ring groove that goes directly into the pin area for better oiling there. A JE thing. Well worth the $485 I paid TEP for them for custom made and flycut pistons. They would be $450 for standard bore sizes. JE wanted $650! Got them in less than 3 weeeks just before racing season, and custom made. Not bad. Tim C. Link to comment Share on other sites More sharing options...
kev Posted March 27, 2002 Report Share Posted March 27, 2002 Yes they are nice and light and shinny 8). I got my JEs for $440 through my machinist made specifically for floaters, 8:1 CR, and 20 over. Machine shops get good deals on these pistons if they use them a lot, it just depends ont he price they want to sell them to you for. kev Link to comment Share on other sites More sharing options...
Tim_C. Posted March 27, 2002 Author Report Share Posted March 27, 2002 Yep. I also meant the sleeves go in the rods so the pin can float. The pistons come with clips for the pins on a full floater set-up. We weren't going to go full float at first, because there really isn't any advantage except that they can be removed from the rod again a lot safer. We decided to do it because my machinist said if he didn't heat the rod up enough, the pin will go part way in and get stuck. If that happens, they have to use a press and butt up against the piston to finish pushing the pin in. That can easily break the piston. He didn't want to go crazy heating the rod to open up the hole more either due to temperance issues. They do just fine without the floating ability, but also the piston is used to press them back out later if needed, and they will break if not done with the right amount of finess. We don't understand why JE uses snaprings instead of springlocks. The snapring style needs 2 rings per groove, 4 per piston. Springlocks are better, but require a different groove, so that's probably why JE doesn't use them. They were making pistons before springlocks became the norm, so they probably don't want to change all of their groove sizes. Tim C. Link to comment Share on other sites More sharing options...
kev Posted March 27, 2002 Report Share Posted March 27, 2002 I don't think I am familiar with the snapring style. I did notice the two rings per side on my pistons. I am also familiar with the single almost like a c ring that is used on most motorbikes. I agree with you on the floaters. The best thing about them is they can be removed very easily without potential damaging of the piston. One disadvantage about them is that if the bushings aren't machined to the right size and with that short of a skirt, it can cause piston slap which isn't the biggest deal it is just annoying. Good luck on the rebuild kev Link to comment Share on other sites More sharing options...
Tim_C. Posted March 27, 2002 Author Report Share Posted March 27, 2002 Good reminder on the slap thing. I better call my machinist and make sure he knows what he's doing. I'm sure he does, because he's done many a full floater, but I don't know about whether there is something different about the JE shorter skirts that may raise an issue there. The shop uses an adjustable ball that comes out the side of a machining stick/pole/rod (you've probably seen them). It mashes the bronze sleeve into the roughed up hone on the rod end. Then they hone it to size from there. He usually likes his tolerances like that tight, so hopefully it comes out right. The clips I got with the JE's are snapring style. Snapring pliers to install and remove. The "C" type is the spiral locks. I think Keith Black, Wiseco, and Ross uses them. Tim C. Link to comment Share on other sites More sharing options...
wolvorine4 Posted March 28, 2002 Report Share Posted March 28, 2002 where can i order them? what are the specs? Link to comment Share on other sites More sharing options...
Tim_C. Posted March 31, 2002 Author Report Share Posted March 31, 2002 I ordered mine from TEP. racetep.com They are About $435 if you go with a standard bore size. There is a GP for Wiseco Forged for less, so maybe that is better for the price. I don't know what the piston to wall clearance on the Wiseco's are. The JE's are .004" measuring up .5" from the bottom of the piston. Forged pistons with tighter clearances means they are high enough quality to not expand so much, and cause a little slapping when cold. I heard Wiseco's are among the best for fit & quality too, so I'm sur ethe GP would be good to get in on. Tim C. Link to comment Share on other sites More sharing options...
Mark_T Posted April 21, 2002 Report Share Posted April 21, 2002 Tim C Pison slap is only a problem on old rings that have lost tension. They can't hold the piston vertical in the bore when you make a quick speed change like bliping the gas. With lghter pistons I will be harder to get piston slap because there is less weight for the rings to keep vertical. Have fun Mark T Link to comment Share on other sites More sharing options...
Tim_C. Posted April 22, 2002 Author Report Share Posted April 22, 2002 Thanks Mark, I like the forged too because they have a lot shorter skirt, so less of a chance for that too. Tim C. Link to comment Share on other sites More sharing options...
Joel Posted April 30, 2002 Report Share Posted April 30, 2002 Hey guys, I just weighed my new pistons, and they are 130 grams ea. lighter than my .060 over hyper-u's were! Â That's a lot for you guys who don't know. Â These are .075 over too. Â I will even lose a tad more weight by putting the sleeves for the floaters in because they are bronze, and steel needs removed to fit them in. This type of piston weight reduction will gain RPM's much faster, and go higher more safely. Â Should be a big improvement on HP and Torque numbers. Â So, not only are they more of a bulletproof piston, but they are much lighter, and have an oil galley from the oil ring groove that goes directly into the pin area for better oiling there. Â A JE thing. Â Well worth the $485 I paid TEP for them for custom made and flycut pistons. Â They would be $450 for standard bore sizes. Â JE wanted $650! Â Got them in less than 3 weeeks just before racing season, and custom made. Â Not bad. Tim C. How durable is the sleeves after a .075" bore-over? What is the maximum? Joel Link to comment Share on other sites More sharing options...
Tim_C. Posted April 30, 2002 Author Report Share Posted April 30, 2002 Well, we'll find out how durable the sleeves are. They are big enough for lots more really. My machinist does lots of Jap engines, and he says the roundy guys go even bigger, and run 7500+RPM all night long. Tyrell is said to have gone .160 over with no issues, but it was a single day race in Nevada.where he averaged 165MPH, supposedly with that engine. Tim C. Link to comment Share on other sites More sharing options...
Joel Posted April 30, 2002 Report Share Posted April 30, 2002 Well, we'll find out how durable the sleeves are. Â They are big enough for lots more really. Â My machinist does lots of Jap engines, and he says the roundy guys go even bigger, and run 7500+RPM all night long. Â Tyrell is said to have gone .160 over with no issues, but it was a single day race in Nevada.where he averaged 165MPH, supposedly with that engine. Tim C. Who is this Tyrrell guy? He's awefully pissed off at me, and all I wanted to proof of his claims. 400WHP seems awefully high for a claim on a 14B (which the engine pics don't reflect) at 28psi (with no BOV). He claimed alot of things that made him sound like he had no idea what he was talking about. I would much rather hear this stuff from someone like yourself. Since this is kind of offtopic, maybe we can talk off here in email? Joel Link to comment Share on other sites More sharing options...
artinist Posted March 3, 2003 Report Share Posted March 3, 2003 since you guys seem to know what you are talking about when it comes to pistons, can you guys comment here. http://www.starquestclub.com/index.pl?boar...;num=1046724019 thanks, Link to comment Share on other sites More sharing options...
plavacca Posted March 4, 2003 Report Share Posted March 4, 2003 hey Tim i was still debating on the piston issue from before when you told me to be carefull about getting hyper-u's, since it worked out well with the J E's i think my mind is made up and will give steve a call. thanks paul 86tsi 91gsx Link to comment Share on other sites More sharing options...
artinist Posted March 4, 2003 Report Share Posted March 4, 2003 i think the question now is, who has the better deal on them? Link to comment Share on other sites More sharing options...
Richie_Rich Posted March 5, 2003 Report Share Posted March 5, 2003 Before you go buying any pistons, figure out exactly what you are willing to settle for. I've got the Wiseco pistons. Supposedly 8:1......I don't think so. :'( I did all the match and blueprinting. It's more like 7.5:1 if you just drop them in. The added cost is not worth it in my opinion for .5:1 increase I ended up decking my block to .010 deck height and will have to use a .030 gasket to get 7.97:1. The decking cost about $50 and the gasket will probably be another $90. The dish came out to 14.2cc. I hear the JE's are 13cc's. I called TEP and talked to some idiot that said the 8:1's they sell are flat tops. That's not true, but I couldn't convince otherwise. I haven't gone all the way thru my calcs yet, but if I was to do it again, I'd consider using a forged stock spec flat top and shorten the rod length til I got 8:1. Rich Link to comment Share on other sites More sharing options...
artinist Posted March 5, 2003 Report Share Posted March 5, 2003 what abou you JE owners, what do you think? i thought JE had 8.0 and 8.2, i dont nknow how they could also make the same miscalculation of selling those with those spec yet be 7.5 Link to comment Share on other sites More sharing options...
89tsi20g Posted March 6, 2003 Report Share Posted March 6, 2003 hmm...., i bought my JE's from Steve (TEP) 5 yrs ago, he said they were 8:1??? rob NJ. Link to comment Share on other sites More sharing options...
rjf Posted March 6, 2003 Report Share Posted March 6, 2003 I haven't gone all the way thru my calcs yet, but if I was to do it again, I'd consider using a forged stock spec flat top and shorten the rod length til I got 8:1. This is probably not a good idea for several reasons: - The rod to stroke ratio of this engine is already off the scale ugly and making the rod shorter just makes matters worse. - if the cyl walls are exposed when the piston is at TDC, the relatively cool walls of the cyl tend to impede efficient combustion. - if the cyl head has any quench area at all, the increased gap will destroy the quench effect. A consideration for piston selection is to look at using pistons for a Toyota R22 engine. They are available in more sizes, have the same pin diameter, and their pin to crown height is very close. Link to comment Share on other sites More sharing options...
Richie_Rich Posted March 6, 2003 Report Share Posted March 6, 2003 When I measured my deck height, before I decked the block, with the Wiseco pistons, I came up with about .033. Using .033 deck height, stock .043 gasket and a flat top piston, I get 8.55:1. (This assumes the compression height is the same for the stock flat top vs. our dished piston) For those that don't know, "Compression height is the distance from the center line of the wrist pin to the top of the piston. I know that the Wiseco piston has the same compression height as the stock ones that were in the motor originally. In reality, my Felpro Gasket is about .052 compressed, so I'd get 8.43:1. I haven't check the compression height of a stock flat top, so I have no idea if it's the same as a stock dished piston. The numbers above are also assuming a Marnal head with 73.5cc camber. (Measured by myself) Stock is about 75.5cc. There is no quench area as our heads are hemi design. When I talked about shortening the rods, I was maybe talking about .010. This is nothing. I lost .007 during a normal rebuild. Plugging in the stock 75.5cc head, it dropped the compression about .25:1. So, if you do a little work on the camber of a Marnal, you can increase the volume, thuss lowering the compression a bit. I have to say one thing, this thread is getting way too technical for the recent question posted. My fault. All this info is swimming around in my head. Bottom line, make sure what you are willing to accept. I wasn't willing to accept only 7.55:1, so I went off the wall and bluprinted my motor. I guess I'm kindajz that way. Too much a prefectionist in many ways. (I am building a daily driver, drive to work car and am going way overboard :) Rich Link to comment Share on other sites More sharing options...
chiplee Posted March 6, 2003 Report Share Posted March 6, 2003 what abou you JE owners, what do you think? i thought JE had 8.0 and 8.2, i dont nknow how they could also make the same miscalculation of selling those with those spec yet be 7.5 I have JE 8:1s and if they are actually 7.5:1 I'll be thrilled. That .5 buffer is fine by me. It allows more boost prior to detonation, and boost is worth WAY more HP than static compression so lower static only lends durability to my engine. My JEs have been abused by 20+psi lean outs from a 20g and never shown any signs of wear. The look like the day I bought them. Tim, I though RPW's reason for using the hyperu's was piston weight? what's up with that? Link to comment Share on other sites More sharing options...
Boosted_One Posted March 6, 2003 Report Share Posted March 6, 2003 I agree with Chip.... 7.55:1 works great for me! I am glad the error goes to the lesser side than more personally. Link to comment Share on other sites More sharing options...
Tim_C. Posted March 6, 2003 Author Report Share Posted March 6, 2003 The Hyper-u's are lighter, and stronger against breaking. However, they melt easier than stock. So, not much insurance against a lean out. They melt fast. I melted mine on stock boost on a 120 mile trip. My AF meter was wacked, and it was running lean without me being aware. I'm going hyper-u on my 85 since the highest boost it will ever see is 7PSI. The Aussies are running MPI, so that ensures fuel a lot better than our TBI. Link to comment Share on other sites More sharing options...
Guest Posted March 19, 2003 Report Share Posted March 19, 2003 How much can u safely bore out a 2.6 block Link to comment Share on other sites More sharing options...
Tim_C. Posted March 19, 2003 Author Report Share Posted March 19, 2003 Well, the definition of "safely" needs better defined by you? Stock oversize replacements only go up as far as .060 over. Tyrell says he went .160 on a race engine. So far no problems on my .075 over. I only have about 4k miles on it.. Link to comment Share on other sites More sharing options...
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