willz Posted April 12, 2017 Report Share Posted April 12, 2017 So I'm safe with an open head w58 with a 180* cam If I've got great psi across all cylinders I'm running about +13 on the timing Quote Link to comment
Xnke Posted April 12, 2017 Report Share Posted April 12, 2017 ...a "180*" cam is smaller than a stock cam. What Is the intended usage of the engine? I would recommend the Delta 280/0.455" grind or (also a Delta sourced grind) the Racer Brown 325R grind. (275*/0.490 lift.) Any smaller cam wouldn't be much, if any, improvement over the stock cam. 1 Quote Link to comment
willz Posted April 12, 2017 Report Share Posted April 12, 2017 I was thinking of doing a 274 Quote Link to comment
distributorguy Posted April 12, 2017 Report Share Posted April 12, 2017 What are your cylinder pressures now? Quote Link to comment
hang_510 Posted April 18, 2017 Report Share Posted April 18, 2017 I have an Iskendrian 0.490 laying about and a spare U67 to try it on....That's what I'm running. New cam = new (or recon) rockers. Isky set me up with spring rates based on what I told them I wanted to do. Took me awhile to get it dialed in. I also use a cam oiler. Oversize valves and ported, stock ex manifold. I can get to 7000rpms but the alternator(5 so far) screams at me (lifetime warranty :) ) around 6000 I run heavy duty diesel oil. 10 years later, flawless performance! 1 Quote Link to comment
distributorguy Posted April 18, 2017 Report Share Posted April 18, 2017 Hang, run a significantly larger pulley on the alternator to slow it down. A Speedway Motors 4" race pulley could be modified to work. Or install a switch to drop the field coil when you plan on racing. That would help take the load off the bearings. 3 Quote Link to comment
G-Duax Posted April 18, 2017 Report Share Posted April 18, 2017 I use a full throttle switch to trigger a relay to kill the field coil. Been running that for years on my Toyota that I hunt mustangs with. Using a relay triggered by the brake light circuit to make the field coil would also work for a track car. Quote Link to comment
Crashtd420 Posted April 19, 2017 Report Share Posted April 19, 2017 What's the reason for the switch and dropping the field.. sounds like altenators gets unhappy over 6000rpm.. and I get what your saying hook up wise but mechanically what's happening when you disconnect the field... things are still spinning ? Do you hear anything or just over time burn them up? Quote Link to comment
datzenmike Posted April 19, 2017 Report Share Posted April 19, 2017 It now spinning freely and not generating, so no load. It is still spinning twice (or maybe more) the engine RPMs so if the bearing is bad it will still make noise. Quote Link to comment
Crashtd420 Posted April 19, 2017 Report Share Posted April 19, 2017 Kind of like turning an ac compressor on and off then... makes sense ... Quote Link to comment
hang_510 Posted May 6, 2017 Report Share Posted May 6, 2017 Hang, run a significantly larger pulley Or install a switch to drop the field coil when you plan on racing. That would help take the load off the bearings. Larger pulley is what I've been looking for. I'll give them a look. Quote Link to comment
Scgreen620 Posted June 1, 2017 Report Share Posted June 1, 2017 Has any one gotten a cam from isky they recomended the type1 and the type 2 type one is a 470 lift and the type 2 is a 480 lift .. They said there's no special mods needed Quote Link to comment
hang_510 Posted June 1, 2017 Report Share Posted June 1, 2017 Has any one gotten a cam from isky Yes. 1 Quote Link to comment
Scgreen620 Posted June 2, 2017 Report Share Posted June 2, 2017 Yes. What cam did you get and what upgrades did you do Quote Link to comment
distributorguy Posted June 2, 2017 Report Share Posted June 2, 2017 More importantly the cams are 270 & 280 duration. Use the 270 on an otherwise stock motor. The 280 would benefit from head porting and a larger carb such as the 38/38 Weber, along with compression of 9.5:1 of higher. Skip 2 out of 3 and you need the 270 cam to generate higher cylinder pressures. The .010" lift difference is of little consequence. Most stock heads have good flow to .500" lift, but you can gain 30%+ cfm with porting. Quote Link to comment
Three B's Racing Posted June 2, 2017 Report Share Posted June 2, 2017 Bull Crap on the no mods necessary unless those cams are ground on a billet which I doubt. If ground on a used cam, the basic circle will decrease in diameter creating more room between the rocker arm and cams basid circle causing you to have to raise the rocker height to adjust the clearance which will move the wipe pattern likely right off the rockers pad eating up your new expensive cam <-- now that's a long sentense 8>) So what I am getting at is cam geometry will need to be checked and probably new thicker lash pads needed and depending on how thick a lash pad needed you may also need new valve spring retainers to hold in place those thicker lash pads. The stock valve springs approach "coil bind" at about 0.460in lift this is directly from the How to Modify OHC bible. Quote Link to comment
datzenmike Posted June 2, 2017 Report Share Posted June 2, 2017 Isky sells those also. You can cut up a cheap feeler gauge for shims to get it right. Then measure and add up to get the correct lash pad needed I think also, as you get near 0.480" valve lift, the stock springs are close to stacking. Something to research and definitely check for. Quote Link to comment
scooter Posted June 5, 2017 Report Share Posted June 5, 2017 the head on my lz has ferrea valves, isky springs, isky retainers, schnieder lash pads and a z-196 isky cam. (.530 lift 306 dur 264@.050 ) fuckin wails. wails even harder on the naws Quote Link to comment
hang_510 Posted June 5, 2017 Report Share Posted June 5, 2017 What cam did you get and what upgrades did you do.490 lift \ 290 Did everything I could and still daily drive it. That's what I'm running. New cam = new (or recon) rockers. Isky set me up with spring rates based on what I told them I wanted to do. Took me awhile to get it dialed in. I also use a cam oiler. Oversize valves and ported, stock ex manifold. Quote Link to comment
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