dapiper Posted June 9, 2014 Share Posted June 9, 2014 My old Racer Brown grind is spitting chunks. Time for a modern grind Any suggestions for grinder and profile? Target is 6500 RPM or maybe 7K for peak power, 550 HP at 25 psig. What say all you gurus? Quote Link to comment Share on other sites More sharing options...
Bernardd Posted June 9, 2014 Share Posted June 9, 2014 Elgin or Isky is where I would spend my money. Quote Link to comment Share on other sites More sharing options...
Tony D Posted June 10, 2014 Share Posted June 10, 2014 Racer Brown is a pretty modern grind as they were ahead of their time... Isky should have something that will work. Quote Link to comment Share on other sites More sharing options...
CarJway Posted June 16, 2014 Share Posted June 16, 2014 Give Isky a call, and tell them what your goals, purpose of the car, etc. They will work with you to build something that suits your needs. Quote Link to comment Share on other sites More sharing options...
Xnke Posted June 17, 2014 Share Posted June 17, 2014 What grind number was your Racer Brown cam? I know where some of the older datsun profiles went to, and JWT didn't have them...they only have the old stock cams, to my knowledge. Quote Link to comment Share on other sites More sharing options...
dapiper Posted June 19, 2014 Author Share Posted June 19, 2014 Thanks for all the comments. The RB cam profile is SS-56-SS-54-110. I wud post the cam card if I knew how. Where is the insert pic command? Paste does not work either Have talked to Elgin and Isky, but went into black hole. Will try Ron again. JWT has very pricy $560 cam (with 480 lift and 256 deg (@ .025" lift at valve) duration and 32 deg overlap, P/N L6 A280Z-00C1M. This is more that the RB cam, prolly too much. This cam is a symmetric profile. MUST use their valve springs, ($130) 75 psi at stock height (1.6") and 200 psi at lift, which seems low, especially on seat at boost. The cam is a stock billet, no core reqd. They have no retainers or lash pads. The base circle is 2.3" which would call for near stock lash pads (140-150) depending if you have to shim your cam towers due to head milling or how much your valves are sunk Here is quote from Ben Phila. He has been very helpful. paste kaput The RB cam has 20 deg over lap, 480 lift, 244 I, 236 E durn at 025 valve lift, which is asymmetric. I get 12 "Hg vacuum at 800 RPM with a CR of 8:1. Peak power is 435 RWHP at 6200 RPM. I have tried the 270 and 284 Schneider grinds which were way too much cam for the street. Soggy below 3k with less power on top. All top end. The idle vac was only 6-8"Hg for the 270 and 3" for the 284. This is unacceptable. Would have to idle at 1500. Did have more area under torque curve, once awake. Quote Link to comment Share on other sites More sharing options...
NewZed Posted June 19, 2014 Share Posted June 19, 2014 I wud post the cam card if I knew how. Where is the insert pic command? Paste does not work either Save the thing you want to paste as an image (.jpg or whatever), click More Reply Options on the Hybridz page, and attach the image. A great tool for saving images is the Snipping Tool in Windows 7 and beyond. It's in the Accessories folder. It saves files with a .png extension. Quote Link to comment Share on other sites More sharing options...
Xnke Posted June 20, 2014 Share Posted June 20, 2014 (edited) Call delta camshaft and ask for the Racer Brown 325R profile on a 110 degreen lobe seperation angle. That would be 275* seat-to-seat, and 250* at 0.050" lift, with 0.475" valve lift on 110* lobe seperation, so something similar to 35/65 65/35 valve events. Sound similar to what you have now? The standard schneider grinds are all on too narrow a lobe seperation for good idle vaccum. the stock lobes were on a 108 lsa, but when adding duration the LSA has to get wider to maintain that vaccum. Less material removal needed to just keep the LSA the same or close, plus you get the rowdy idle everyone thinks of with a "cammed" engine. Edited June 20, 2014 by Xnke Quote Link to comment Share on other sites More sharing options...
CarolinaTZ Posted September 12, 2014 Share Posted September 12, 2014 Hey Dave! Long time no see. Hope you are doing well. I was thinking about you and the "ole girl" the other day....was gonna call but couldn't find your number. I wanted to share some information I found in an old '76 Hot Rod magazine Datsun article that shed some light on the history of the Jim Cook body kit. I don't know if I ever told you there were only 14k miles on the Zap when I cut the quarters to install the kit....not sure if it was wise to cut on such a perfectly rust-free Z! I also have a pretty cool keepsake....Jim Cook sent me an actual photo of their Z car showing the "new" airdam because the newest catalog (circa '84ish) didn't have it listed. I bought the airdam based on the photo and it all got installed at the same time. Anyway...onto the cam. Here's a copy of your cam card you sent me when we realized I was running the same RB part number. It looked like my lobes were waring also, the last time I looked at my cam...hopefully not with 30k miles. There may be something better out there but I understand this is supposed to be a good turbo cam. Quote Link to comment Share on other sites More sharing options...
dapiper Posted September 13, 2014 Author Share Posted September 13, 2014 That you Joe?. Yeah that's the cam card for the hipo RB grind. Lot's of grinders have cams that copy that one. Joe was the original owner/fabricator of my Jim Cook chassis. Still trying to reinstall the regrind from Schneider, but lost cam trigger sensor. Went kaput when winged it with the chain block....duh. My dumb luck. I think I still have your old phone no. Will try that later. just now checking out my posts. Looking to upgrade turbo soon and setting up deal to fab equal length turbo headers for the L28. Thanks for all the CarolinaZ info. Quote Link to comment Share on other sites More sharing options...
CarolinaTZ Posted September 15, 2014 Share Posted September 15, 2014 Yep, Dave.....it's me. Glad to see you're still developing the car. Good luck with the header and other upgrades. Give me a call when you get some time! Quote Link to comment Share on other sites More sharing options...
Kennymonster Posted January 20, 2015 Share Posted January 20, 2015 I called Isky for a similar 6.5k and 7k power setup, and he recommended the int .490 / 276 ext .480 / 268 grind that others have run on this forum. I could tell the spool was improved vs. the schneider I had, however the motor gave out 20 minutes into the break in lol (bad ring). Going back to an NA set up, so I have the cam for sale if interested Quote Link to comment Share on other sites More sharing options...
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