RacnJsn95 Posted November 7, 2012 Report Share Posted November 7, 2012 Figured I would rename this rather than start another thread. Thoughts on opening up the wrist pin hole on the rod to 22mm?? Anyone ever do it? I'm wondering how bad it would effect the integrity of the rod, or if it would be OK. Quote Link to comment
metalmonkey47 Posted November 7, 2012 Report Share Posted November 7, 2012 Why would you want to do that though? Aftermarket piston options? Quote Link to comment
RacnJsn95 Posted November 7, 2012 Author Report Share Posted November 7, 2012 The ability to run off the shelf aftermarket pistons, vs more expensive custom made pistons... For instance, the idea that I'm kicking around in my head would use SR20DET pistons, which have a 22mm pin instead of the 21mm pin most of the L series and Z series pistons use. Quote Link to comment
TFM1066 Posted November 7, 2012 Report Share Posted November 7, 2012 in my racing motors I used to bush the small end of the rod, now I know just run steel to steel at the pin and rod (cut down on the cost). I did inlarge the small end to 22mm with no loss of strengh, you shouldnt have a problem. The SR20 piston if a far better casting then the old L-piston and has a higher pin so its much lighter. what rod length would you use? Quote Link to comment
RacnJsn95 Posted November 7, 2012 Author Report Share Posted November 7, 2012 Z20e rods, 152.5mm long. Currently I have 3 build options in my mind: A ) Z22 crank, Z22 block +1mm, 2.2L SR20det stroker pistons (29mm pin height, 88mm bore), Z20E rods. 92/2+152.5+29 =227.5 (piston deck height +.05mm above block based on 227.45mm block height) This would yield a 2238.2 cc engine. B ) L20b crank, Z22 Block +.5mm, 2.0L SR20det pistons (32mm pin height), Z20E rods. 86/2+152.5+32 =227.5 (piston deck height +.05mm above block based on 227.45mm block height) This would yield a 2068.6 cc engine. C ) L20b crank, L20b Block +1mm, 2.0L SR20det pistons (32mm pin height), Z20E rods. 86/2+152.5+32=227.5 (piston deck height +.05mm above block based on 227.45mm block height) This would yield a 1998.3 cc engine. Either way it goes, the plan is to turbo the engine... Think the wrist pin of the rod being bored out to 22mm from 21mm would still be OK under boost? Quote Link to comment
TFM1066 Posted November 7, 2012 Report Share Posted November 7, 2012 ayes pin end reemed to 22mm is ok under boost. keep everything simple, that well keep the cost down and the parts easy to get Quote Link to comment
TFM1066 Posted November 7, 2012 Report Share Posted November 7, 2012 All the force applied to a piston pin and rod is on the bottom half of the small end, not the top of the small end Quote Link to comment
RacnJsn95 Posted November 7, 2012 Author Report Share Posted November 7, 2012 ayes pin end reemed to 22mm is ok under boost. keep everything simple, that well keep the cost down and the parts easy to get As it is, I have everything except the pistons for the short block of any of the above listed build combos... I'm watching the 2.2L SR pistons on ebay, they look like a smokin deal if I can get them for the minimum bid. However, I am debating if I really want to go the 2.2 route using the Z22 crank because it is not a fully counter balanced crank... I'm wondering if it would be better in the long run to go with build option B utilizing the fully counter balanced L20b crank. Quote Link to comment
TFM1066 Posted November 7, 2012 Report Share Posted November 7, 2012 The Z-22, Z-24 cranks is what ive been using for the last 4 years, I run the motors up to @ 8500 RPMs with no problem so its your choice. I do however groove # 2 and #4 main bearing saddle in the block and drill another hole @ 45 degrees from the factory one in the main bearing to improve the rod oiling issues the these motors have. Quote Link to comment
RacnJsn95 Posted November 7, 2012 Author Report Share Posted November 7, 2012 The Z-22, Z-24 cranks is what ive been using for the last 4 years, I run the motors up to @ 8500 RPMs with no problem so its your choice. I do however groove # 2 and #4 main bearing saddle in the block and drill another hole @ 45 degrees from the factory one in the main bearing to improve the rod oiling issues the these motors have. Very interesting... Thank you for your insight... Any pictures of the oiling mods? Quote Link to comment
datzenmike Posted November 8, 2012 Report Share Posted November 8, 2012 I have a spec for an SR20 piston pin height of 31.74mm and pin diameter 21.98mm in my racing motors I used to bush the small end of the rod, now I know just run steel to steel at the pin and rod (cut down on the cost). What was the cost to bush each rod small end? Quote Link to comment
RacnJsn95 Posted November 8, 2012 Author Report Share Posted November 8, 2012 I have a spec for an SR20 piston pin height of 31.74mm and pin diameter 21.98mm What was the cost to bush each rod small end? My searching has come up with both 31.74mm and 32mm... The CP piston catalog lists SR20 pistons as 1.26"(/.03937=32.004mm)... I've seen more 32mm in all the piston kits i've looked to purcahse than 31.74 that I've found only a handful of times on forums. I've seen 21.98mm - 22mm for the pin size. In the case of the first pistons I mentioned, they are custom w/ a 29mm pin height, which would work out perfect with the Z22 crank. Quote Link to comment
datzenmike Posted November 8, 2012 Report Share Posted November 8, 2012 Yup. shorter is safer. Are the custom ones forged or regular hyper eutectic? Quote Link to comment
RacnJsn95 Posted November 8, 2012 Author Report Share Posted November 8, 2012 Yup. shorter is safer. Are the custom ones forged or regular hyper eutectic? Everything I'm looking at, and have listed in the possible builds are forged. Quote Link to comment
TFM1066 Posted November 8, 2012 Report Share Posted November 8, 2012 as for pictures I have a very hard time trying to post them here on Ratsun, plus my battery is dead in (in the camera) and i left the charging cord in Cabo San Lucas a few week back and havent got a replacement yet, is the Sr20 a floating pin? 21.98mm is the pin dia, 22mm is the hole size that the pin slides into, hencs 22mm the differances is oil clearance .008 in inches, pin bushing install was @ 20-25.00 a rod included the bushing. Quote Link to comment
RacnJsn95 Posted November 8, 2012 Author Report Share Posted November 8, 2012 The pistons I'm looking at appear to be full floating as they have wrist pin locks... http://cgi.ebay.com/ebaymotors/CP-Pistons-Nissan-SR20DET-Stoker-2-2L-Include-Rings-Wrist-Pins-Wirst-Pin-locks-/110973982516?pt=Motors_Car_Truck_Parts_Accessories&hash=item19d6909734 Does that throw a wrench into the equation? I've seen both available. Quote Link to comment
datzenmike Posted November 8, 2012 Report Share Posted November 8, 2012 Well you can over size the rod hole and press fit the pin like most or over size the rod and put a bushing in and have floating pins. Floating reduce friction and free up some HP but costs. You have to size the hole anyway so.... Quote Link to comment
RacnJsn95 Posted November 8, 2012 Author Report Share Posted November 8, 2012 I think I would rather size the pin hole in the rod just enough to get them on (press fit, rather than floating)... No sense in taking more meat out of the rod than necessary... Quote Link to comment
RacnJsn95 Posted November 8, 2012 Author Report Share Posted November 8, 2012 Finally got the info on the 2.2L SR stroker pistons from CP as the seller didn't have the info I wanted on them (CR, Dish volume), the pistons were designed for a 9.5:1 compression ratio with a stock SR20DET head (45 or 46.1cc chamber??)... The dish is -15cc.. So I built this theoretical (L?)Z22e(t?) in the Ozdat engine builder... Compression ratio with an open chamber U67 (45.2cc) head would be 9.307:1 ... If I use the Z22 head I have (57cc?) static CR would be 8.068:1... Additionally, if I opted not to turbo it, I could run the closed chamber W53 head I have and the CR would be 9.859:1 Quote Link to comment
EricJB Posted November 8, 2012 Report Share Posted November 8, 2012 I think I would rather size the pin hole in the rod just enough to get them on (press fit, rather than floating)... No sense in taking more meat out of the rod than necessary... The difference is about .0008 inch. Floaters make it a lot easier to disassemble down the road. As TFM said, I run floaters with no bushing as well. Quote Link to comment
RacnJsn95 Posted November 8, 2012 Author Report Share Posted November 8, 2012 Think I ran into a snag already... It seems the piston end of the SR rod is 23.62mm, and from what I've found a typical L rod is 25.4mm... Although the Ozdat engine builder says they're all 25.4 (SR20, L20b, Z20e)... Can anyone confirm? So the search continued for another "economically priced" forged piston that would work... I came across the 88-92 4g63 stroker pistons. 86mm bore, 21mm pin so no need to bore the rod end, 28.7mm pin height, and it looks like the exact same PE width as the L series... 92/2+152.5+28.7=277.2-224.45= -0.25mm in the hole... The 4g63 piston mentioned has a -22.2cc dish... I could utilize a closed chamber head and achieve a CR of 8.443:1 1 Quote Link to comment
kyuji Posted July 14, 2017 Report Share Posted July 14, 2017 The difference is about .0008 inch. Floaters make it a lot easier to disassemble down the road. As TFM said, I run floaters with no bushing as well. Yeah this is a bad idea. Lets assume you can bore it out straight enough and also able to get the propper oil clearence. You still have a critical problem. The pin end of the connecting rod isn't a proper bearing surface and isn't designed to hold a film of oil like the material of the bushing. Quote Link to comment
G-Duax Posted July 14, 2017 Report Share Posted July 14, 2017 Personally, I wouldn't run a floating pin in a steel bore, but I've heard of people doing it on a NA, and getting away with it. Maybe if the bores were moly coated... FJ, and LD have 22mm pin bores. I'm using aftermarket H-beam FJ rods (150mm), just re-bushed them down to L-spec 21mm. Quote Link to comment
datzenmike Posted July 15, 2017 Report Share Posted July 15, 2017 Five year old topic. RacnJsn95 hasn't posted in over two years. Quote Link to comment
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