ca18 bluebird Posted March 26, 2009 Author Report Share Posted March 26, 2009 oh yeah and does anyone know a mandrel bender in adelaide to make a custom header to my specs? i can weld it all up myself, and even source the tubing if need be but i need mandrel bends made. If i can't find anyone ill just go down to aussie discount mufflers and see if they can make it to my specs Quote Link to comment Share on other sites More sharing options...
orangeLJ Posted March 26, 2009 Report Share Posted March 26, 2009 any muffler shop should sell you mandrel donuts or single bends. Just go down and ask for the angles you need. Quote Link to comment Share on other sites More sharing options...
beerhead Posted March 27, 2009 Report Share Posted March 27, 2009 The rod ratio is the length of the rod / stroke, nothing to do with the bore of the engine. sr20 rod length = 136.3 / 86mm stroke = 1.58 Rod ratio sr16 rod length = 145mm / 68.7mm stroke = 2.11 Rod ratio!! F20C rod length = 153 mm /84mm stroke = 1.82 Rod ratio The longer your rod, the the more parallel to the block the vector of force is applied on the crank from the rod, the longer your bearings will last and the less the pistons skirts will eat the bores out of your block. Catch 22 : the shorter the rod ratio, the more leverage your rod puts on the crank, the more bottom end torque the motor will develop :( The SR16's are a rev monster. They're comparable to an average motorbike motor for its ability to rev from these specs, the SR20 won't be as happy having the ring revved out of it, but the will make heaps better torque that's for sure. BTW, I'd just tack the extractors together and get an exhaust shop to weld it up. They fill the pipes with inert gas before welding to ensure that the weld flows through without oxidisation. This stops the welds cracking under extreme heat. Sounds like you've been researching this really well though, can't wait to see the results ! I hope my 5S will keep up :) Quote Link to comment Share on other sites More sharing options...
styler Posted March 27, 2009 Report Share Posted March 27, 2009 sounds like an interesting build, i like! Quote Link to comment Share on other sites More sharing options...
ca18 bluebird Posted March 27, 2009 Author Report Share Posted March 27, 2009 (edited) The rod ratio is the length of the rod / stroke, nothing to do with the bore of the engine. sr20 rod length = 136.3 / 86mm stroke = 1.58 Rod ratio sr16 rod length = 145mm / 68.7mm stroke = 2.11 Rod ratio!! F20C rod length = 153 mm /84mm stroke = 1.82 Rod ratio The longer your rod, the the more parallel to the block the vector of force is applied on the crank from the rod, the longer your bearings will last and the less the pistons skirts will eat the bores out of your block. Catch 22 : the shorter the rod ratio, the more leverage your rod puts on the crank, the more bottom end torque the motor will develop :( The SR16's are a rev monster. They're comparable to an average motorbike motor for its ability to rev from these specs, the SR20 won't be as happy having the ring revved out of it, but the will make heaps better torque that's for sure. BTW, I'd just tack the extractors together and get an exhaust shop to weld it up. They fill the pipes with inert gas before welding to ensure that the weld flows through without oxidisation. This stops the welds cracking under extreme heat. Sounds like you've been researching this really well though, can't wait to see the results ! I hope my 5S will keep up :) yeah i know its got noting to do with the bore, but i just posted the bore as well as the stroke and knew off hand that the rod length was mid 150's but didn't know the exact measurement so didn't post, but i have looked at it before and knew the f20c rod ratio is closer to the sr20 than it is the sr16ve. But yeah you are right the sr16ve is a stupid rev monster would go nicely with a big turbo and 13,000rpm. thing is you are 100% the sr20 wont like having the absolute crap revved out of it like the 16ve, this is why i am setting it up to make the power a little lower in the power band. However in saying that people in the states wack a set of valve springs in the sr20ve's and rev to 10,000rpm+ with their less balanced 4cw crank. (the sr20ve used a 4counter weight crank to save weight and have it rev up a bit quicker, but at higher rpm it will munch your bearings a lot quicker). There are plenty that rev to 9000rpm all day and have lasted a long time, but the sr20 WILL need a rebuild quicker than a 16ve will simple. Great info dude keep ya posts coming today i swapped my ma61's for a set of wantanabes so the car no longer has the wheels pictures, but i think i will buy another set as i love those rims Edited March 27, 2009 by ca18 bluebird Quote Link to comment Share on other sites More sharing options...
Ke20nut Posted March 27, 2009 Report Share Posted March 27, 2009 all this work for a ke70? :( Quote Link to comment Share on other sites More sharing options...
ca18 bluebird Posted March 27, 2009 Author Report Share Posted March 27, 2009 (edited) Another reason i choose to start with the 16ve is because what what i have found in my research of these engines is that there is a bit of difference in flow between heads. Now the sr20ve and sr16ve heads are identical in everyway but cams, but there is a big variance in flow figures from standard flowed heads, the earlier castings have seen figures in the high high 270cfm@ 28 inches where as some of the poorer examples are as low as 240. Now that there is the difference between a decent port and polish. Most the sr16ves where made earlier than the 20ve's and therefore seem to flow a bit better, i haven't yet seen a poor flowing 16ve doesn't mean it don't exist but i just haven't seen it. This could be because the head molds weren't replaced regularly/at all and just got sloppy or it could be because the molds where changed to suit pollution standards each year i don't really know its all speculation, but the earlier castings flow best and the later ones flow worse oh yeah the manifold will be taken to my mates work who designs and puts together semi trailers for a living, so i will have more faith in his welding skills and equipment than a zorst shop. In saying that i wouldn't mind a zorst shop to do it Edited March 27, 2009 by ca18 bluebird Quote Link to comment Share on other sites More sharing options...
13BT_KE20 Posted March 27, 2009 Report Share Posted March 27, 2009 go see drew at AAA exhausts for the bends. Tell him the boys at MRE (mildren's) recommended you and he'll look after you Quote Link to comment Share on other sites More sharing options...
ca18 bluebird Posted April 1, 2009 Author Report Share Posted April 1, 2009 ok found out today that the engine got cassified as dangerous goods and had to be shipped by sea insteed of air. So there is a little set back, but should still be here around friday/sat monday ish. i have tacked up some engine mounts to the crossmenber, i just tried to mimic the ones on the s13 member i have here, but couldnt get the best reading so want to test fit before finishing the welds off. also found out the 16ve i got is a late model one, my mate in nz goes "great news buddy the engine is mega clean its a 2001 version" i was like oh yay but gay. but meh no big deal after all they could have changed the castings just on the 20ve for emmitions/economy (as the 20ve was mated to a cvt auto) or what ever and not the 16ve i don't really know tbh. so will post some updates when i have some, but for now ill have to play the waiting game. Quote Link to comment Share on other sites More sharing options...
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