looking forward to another early Olds powered project starting to gather a pile of go fast parts that seems to be getting pretty radical nothing ironed out or chiseled in stone yet, in my pile I have, and it'll more than likely be; '55 block, crank, rods with .125 over forged pistons '56 #10 heads, maybe bigger valves and mild port and polish shoot for somewhere around 10:1 compression Horne or Cragar 4x2 with four Stromberg 48's Ronco or Vertex Magneto with mechanical advance aluminum flywheel '37 or maybe later Cad Lasalle transmission V8 style quickchange rear with '50 Merc axles all this in a '27 T roadster biggest question right now is the cam specifically an Isky 505T solid roller I have the spec's just not here with me from what I've read it is a bracket only grind fairly radical, very rough idle, rough enough to maybe lock the mag for no advance and run a ton of initial just to get it to idle would it make sense to drop the compression and put the 4-71 on top to force feed it, I've heard a little forced induction can help mellow a radical cam..? any out there running one of these cams on the street? blown or natural?
No one's jumped on this? I don't know much about Olds V-8's but do know something about radial cams on the street.I looked up that 505T Isky grind,couldn't find Olds specs but did get SBC info ,should be similar,.505 lift ,108 lobe separation,254 degrees duration at .050 lift,3000-7000 rpm ,race track cam.This cam would be pretty lumpy in a 350 Chevy around town.So....you want a racey engine for the street,you got one should be fun out on the backroads in a light car with gears and noticable in town.....
Depends a lot on how much overlap is built into the cam. I've built a similar engine in '64, ran it one summer, and have now been street driving it since 2004 in a '16 T Bucket with a Champ Quickchange (rough ride in a T). Engine: 324 bored to 4" = 345 CID #10 heads ported, with 440 Dodge valve springs cam TRW hydraulic refered to as a 3/4-Full Grind (lost the specs) lopey idle pistons JE full skirt 11:1 balanced rotating and reciprocating assembly rocker arms Gotha adjustable, Isky push rods, Crane anti-pumps intake Edelbrock with 4 Holley94s with stock jets and power valves @ 4.5psi Carter low pressure electric pump and Holley regulator, synchronized linkage Transmission: 55 Olds hydro with 53 Olds short tail shaft (allows me to have at least an eight inch long driveshaft), stock stall fluid coupling, low gear valve body modification as per Hi-Rank Corp instruction manual. Rear axle: Lynn QC open differential 4.1:1 ratio (this engine likes it, tried a 3.25:1 to get some highway fuel economy but was not cutting it in city traffic) The music is sweet. Ignition: MSD 6A triggered by a Ford pickup coil adapted to a stock Olds distributor. No vacuum advance - only centifugal (don't know the curve or the initial timing - my old Snap-on t-light multi flashes on the MSD signal). The MSD softens the idle quality and allows me to run 92 octane unleaded. Runs like crap with any of the methanol added gasolines. Cooling: Sprint car sized rad, sixblade plastic fan off 71 Pinto mounted on crankshaft. Overheats in gridlock traffic and very slow parades on hot days. (hot rods are made for performin' NOT paradin'). Just looked up the specs in an old Isky catalog: lift is .531", intake 37-73, exhaust 73-37, duration is 290, valve lash is .028" hot. I'd run it on the street and use a good zinc-based oil in it. I'm enjoying my roadster with the vintage Olds engine. Pulls real good in mid range. It is on the heavy side at 2340# due to the rear axle weight and the cast iron Hydro. All the best on this project - keep us posted.
In my opinion, you just have to decide what you want. Do you want a comfortable driver that maintains its tune, has some torque and is fun to drive (Then don't go that radical on the cam.) Do you want a race car on the street that requires constant maintenance and is fun to drive (Then by all means, throw a big cam in it.) I have a big cam in mine and have had a lot of fun over the last 5 years, but I am tired of it. I either need two cars, one for cruising and the interstate and one a "barhopper", or it is time to detune a little. Good luck.
with a big cam - you will need to constantly check all bolts, nuts - i have used a big bottle of red loctite on a T & still have to check everything - windshield gets loose, shocks get loose, headlights get loose, suspension gets loose - red loctite slows it down - doesn't stop it - i still check things at least every 6-8 weeks
I have 3 street cars with solid rollers in them...all with specs close to the ones posted above. I like serious sounding (& running) cars...and I really don't think the maintenance on a "radically" cammed engine is alot more than a mild one. Yea, you might run through the valves a little more (stud girdles and/or poly locks help), maybe tweak the carb. a little more, etc...but it's the price of admission. I myself have always like tight lobe seperation angles on the street, either 108 or 106...lots of torque & seat of the pants feel. Just my opinion... sam
Hi, i think it`s not a good idea to run a blower to mellow a cam. Go with the radical cams with high compression and big ports or have Schneider to regrind you a blower cam , run low comression and smaller ports. You don`t need a lot of cam with a blower, but wide lobe centers. Michael
http://www.dropshots.com/Dolmetsch#date/2006-10-30/20:44:48 Here is one 254@050 .525 lift 108 deg (a hydraulic which is a bit more radical (no lash or clearance ramps) Ign timing must be short and quick. Compression must be on the high side. This is almost 11 to 1. Carb must be perfect. Tuned to allow for low vaccum at idle. It can be done. had this for 10 years but everything thing must be right. Don
Paul I've run some pretty radical cams on the street both car and bike. If you're going to huff it you want a cam with a lot of exhaust duration. As you already know getting mix out is the biggest probalem with a huffer. I'm not an olds expert but if you can just go with general info an extreme cam on the street is not that big a problem. Its a matter of keeping it cleaned, I.E. keeping your revs up and not just idleing around. It will load on you with the cam you want to use. So if your stuck in traffic or at a light you'll have to blip it a lot. As the Ol' Man used to say,"Clean it kid, clean it good." No matter what setup you go with for induction you are going to experience major differences in the way it runs depending on humidity and ambient air temp. Where you are the humidity and ambient is pretty stable, you don't have major swings like we do here so you should be able to set up and run most of the time without it being too tempermental. We can go from 100 and 90% to low 30s and dry in the run of a week or so here. Where you are going to find a problem is if you decide that a trip to Idaho is in order and rought your trip through Eastern Oregon. If you catch my drift.
What HotRodMicky and Dolmetsch said. Whether you want to use a blower or not is a big fork in the road. Happy trails, let us know what you decide to cook up!
I've run 505's and 550's in the past in a FE mtr. The only problem for the street would be the valve spring pressure required IMO They DO sound good
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