Mikelly Posted October 23, 2001 Share Posted October 23, 2001 Spoke with Ron Isky on the phone last night and it seems that I'll be going with a completely different setup all together...Getting rid of the hydraulic valve train and going solid roller with 1.6 rockers. I'm waiting for Ron Isky to get back with me on what I need, but we are gonna shorten the duration up quite a bit and go with a lift that equates to the 520-530 range... Complete motor is gonna come appart for a re-ring and check of everything... Mike Quote Link to comment Share on other sites More sharing options...
Andrew Bayley Posted October 23, 2001 Share Posted October 23, 2001 Mike, Just out of curiosity, how often does a solid roller need to have the lash checked and/or adjusted? I've often thought about going solid roller, but the simple "half turn in, then forget about it" on hydraulics is a nice feature. -Andy Quote Link to comment Share on other sites More sharing options...
Tim240z Posted October 23, 2001 Share Posted October 23, 2001 Andrew, I wondered about this exact subject, but in speaking with my Dad, who runs a solid roller in the race car. He checks at every race, and has not have to reset the tappets for almost a season now. Tim Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted October 23, 2001 Share Posted October 23, 2001 I love my roller but can't properly compare it to standard hydraulic flat tappet as I changed a lot more than the cam. idahoevette website or similar had a great writeup by Herb Halverson (AIR) with a direct dyno before/after of v. similar cams in same motor, one roller and one not. FWIW, going 'roller' for a mild motor does not have to be so expensive....cams are available used or new take outs for $50US and up from ZZ4's/Lt1's etc... OE lifters are cheap and setting up that 'spider' to use OE lifters isn't a big deal, take care of front 'button' and dizzy gear if need be and that's about it. Has been done anyhow...I like Mike's quoted spec's...right in line with built-modded Lt1's, one WA guy has a shoebox or more full of dyno slips....cerberus, LPE might do solid cams for Lt1's?? (drop me a personal email and I'll fwd you to someone who knows the sources). Main advantage for a solid roller IMO (for non high rpm motors) is the lighter lifters vs. hydraulic lifters. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 23, 2001 Share Posted October 23, 2001 Sounds like a great idea. Even with less duration I think you will find that the roller cam ramp speed will out perform a higher degree hydraulic cam. Valve springs to support a roller seem to cost a whole bunch more than they should. But what do I know, I don't build springs. Going to larger diameter springs cost me less than trying to get comparable 1.25 inch ones. Went to cut the valve pockets and struck water instead. These were cast iron 441 heads, hopefully yours are already setup for larger springs. Learned the hard way that 1.6 rockers contact the valve stem with a longer stroke. I would use lash caps the first time around, and pay very close attention to keeping all valve installed heights the same. Stock pushrods may be a bit long. Wouldn't hurt to check roller tip pattern with everything adjusted to spec. Quote Link to comment Share on other sites More sharing options...
Mikelly Posted October 24, 2001 Author Share Posted October 24, 2001 Some of my questions are: Can I run the same Kmotion springs that I'm running on my hybraulic roller motor, and what length pushrod to use... I'm hoping to only have to swap out the pushrods, lifters, rockers and cam... My original intention was to just swap the cam... We'll see... Mike Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted October 24, 2001 Share Posted October 24, 2001 Isky will tell you what spec's/range his cam wants, compare that to your Kmotion specs. Depending on rpm ranges etc lighter weight springs (singles or duals vs. triples, smaller ID's etc)/retainers/keeper combos can add some sweet rpm till you hit float, cost isn't that sweet though...what rpm range you building for BTW? Quote Link to comment Share on other sites More sharing options...
Mikelly Posted October 24, 2001 Author Share Posted October 24, 2001 Well I don't plan to rev above 6000RPMs, and based on the newer cam, I may be lower than that... Mike Quote Link to comment Share on other sites More sharing options...
Mike C Posted October 24, 2001 Share Posted October 24, 2001 On springs, it just depends on the two cams. I have a comp solid street roller 280/280 236 @ .050 and .550 gross lift. Lash is .020 Comp has a hydraulic roller than is 280/280 224 @ .050 and .525 net lift. The mechanical uses about a 15% stiffer spring, but they said the used mechanical spring should be good for the new hydraulic roller. I ran mine on the street quite a bit with valve adjustments every 6000 miles or so. A stud girdle helps maintain lash as well. Be forewarned that even my "small" 1.437 springs required the Crane 11752 rockers that clear 1.65 springs. I don't care for 1.6 rockers as they don't leave as much rocker on the valve tip. Comp said expect a 50 hp swap from my cam to the other one. I am planning on hydraulic in the future as the mechanical is just plain LOUD. Clack clack clack ping ping ping was tolerable when I was 20 in '88 when I built the motor, but not as much so now. If you plan on driving primarily on the street, I would run a bigger hydraulic roller. If it's a pure race car, do the mechanical. Too many people are making big power with the hydraulics now and it's something else you DON"T have to work on IMO. Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 24, 2001 Share Posted October 24, 2001 Mike, as much as I prefer solids, the hydraulic would be fine if you're not going over 6000 rpm. The big issue with hydraulic roller lifters like those retro ones from Comp Cams (not sure about Isky's) is that they are very heavy. Not a problem usually for 6000 rpm and lower for "streetable" spring rates. I still like the clack of solids. The newer tight lash solids are a bit quieter, I believe. Cerberus, BLKMGK pointed out to me a while ago that engines with knock sensors like the LT1 don't like solids - the noise fakes out the knock sensor (possibly?) and tells the ECM you're pinging when you're not. 2 to 3000 miles between valve adjustments is probably a yearly deal for my seldom-to-be driven Z. Heck, my commute is 1.5 miles. Cam Theory: Am I all washed up here? 1. High lift is important for midrange torque (assuming the heads flow at the higher lifts) 2. To get "high" lift (.550"+) with "short" durations like 225-235@.050, you need to go to a roller on a SBC, due to the lifter diameter and base circle radius constraints. 3. Solids can have more area under the curve, since the lash is figured in from the outset and there's no delay in valve actuation (other than lash take-up). Please teach me. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 24, 2001 Share Posted October 24, 2001 If you run on the street figure too do them 2 to 3 months .they won't be off much if at all but pays too check .i run a solid roller .550 lift in my truck small block .Lookin for a solid gor my LT1 .Not much luck though. Quote Link to comment Share on other sites More sharing options...
Andrew Bayley Posted October 24, 2001 Share Posted October 24, 2001 Did either of you guys notice much difference between a roller and hydraulic? Did the butt dyno pick up anything? Also, is a hydraulic roller worth the money? My logic is: if you are spending the money for a wet roller, might as well go solid. -Andy [ October 23, 2001: Message edited by: Andrew Bayley ] Quote Link to comment Share on other sites More sharing options...
Mike C Posted October 24, 2001 Share Posted October 24, 2001 The weight of the hydraulic lifters can be offset by the AFR hydra-rev kit. Check it out on AFR's page. Hydra-Rev These springs between the lifters and head take a lot of the load off the valve springs which extends the upper range of the hydraulic valve train by as much as 1000 rpm! Comp has some new hydraulic rollers that are faster ramp than my mechanical roller. I was looking for a streetable grind at the time, and the mechanical 280 street roller fits the bill perfectly. I plan to switch to cast valve covers first and see what level of noise reduction that provides. The motor is LOUD, however. When it finds a new home in my 'vette, I want quiet and fast which means hydraulic roller. Power delivery is going to be based on lobe centerline and .050 duration primarily, with advertised duration as a good guidline for idle quality. Once again, advertised duration is shaky as manufacturers measure at different lobe lifts. Comp at .006, Crane at .005 and some, like GM, at .001. The lower the lobe lift where measurement takes place, the higher the advertised duration which is why the .050 comparison is so important. Also, mechanical cams are measured at different tappet lift as well, to take lash into consideration, which also can skew comparisons of the two. I like 110 degree lobe separation for the best idle/power delivery. If you like two stroke like power, move to 106 degree separation and 250+ degrees at .050. Increasing lift gives more power without a reduction in idle quality. Regardless of cam choice, I have had trouble eating bronze gears and would recommend a cam that is compatible with an iron distributor gear. The Comp 286 HR seems a good choice (at least for me!) 230/230 @ .050 and .560 lift. I don't usually go for split pattern cams as small chevy's have excellent exhausts, it's the intake where they suffer. FYI, my Camaro at 3500# runs 12.7's at 110 mph with a 2.0 short time. I run 92 octane pump gas and McCreary G60 dirt track tires, through closed exhasut. Figure about 350 rwhp and I shift at about 6500 in first and about 6300 from there. It has 9.8:1 TRW single trough valve reliefs and re-worked GM straight plug 492 castings, a Victor JR., Barry Grant 750 (Not a Demon)and 1 3/4 headers with 2 1/2" compression bent exhaust. This is a mild, very streetable combination that should put a Z in the low 11's VERY VERY reliably at 6500 rpm. (This car was considered REALLY fast when I built it, now EVERYBODY seems to have a 12 second street car ) If you only have one car and like to tinker, the mechanical roller is cool. If you want to drive more wrench less, the hydraulic roller seems a fine compromise with a slight reduction in idle quality since you have to run a bigger cam for the same power. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 24, 2001 Share Posted October 24, 2001 Knock sensor You mean that thing in the block with no wire going too it !! TEC II no need for knock sensor etc. I will catch that flag theif Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 24, 2001 Share Posted October 24, 2001 Mike C, thanks for the lesson. Haven't things like the hydra-rev been out for a long time (spring below the head/above the lifter? Yeah, comparing cams from different manufacturers is tough. 0.050" duration is useful, but comparing mechanical and hydraulic cams with those durations is like apples and oranges. My research on the subject says you need to subtract 8-10 degrees from the 0.050" duration of a solid cam to get a comparable 0.050" duration for a hydraulic. But this ignores the ramps. Like Mike C pointed out, the new Xtreme hydraulics (flat and roller) have agressive ramps. Just compare their seat and 0.050" timings with other designs to see this. The issue is that low lift flow can have an effect on cylinder pressure. So even though a less agressive cam has a 225deg @0.050" duration, it will have higher seat duration than an aggressive ramp cam, lowering the dynamic pressure in the cylinder, if LSA, etc. are the same. Muddy Waters to me. Quote Link to comment Share on other sites More sharing options...
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