I’ve been tackling the somewhat unpleasant task of cleaning out my dad’s house. One thing that makes it bearable is some of the interesting things I’ve found. One of them is an unopened cam from Crane. It’s listed for Ford 221 to 302’s, I don’t recall the date range but it’s in the neighborhood of 1962 to 1974. I copied down the specs for it.
Grind # H-302
Lift Intake 302 483
Exhaust 302 483
Rocker Arm ratio 1.6
I didn’t bother to copy the spring requirements. This cam is still in the box unopened. It’s obviously a racing cam, but my question for those with more experience than me would be if this is at all streetable. I happen to have a block that isn’t being used, along with some other go fast goodies. What I lack is a car to drop the motor in. If this could be used on the street I could easily remedy that problem. If not I’m probably better off putting the cam on ebay and being done with it. So what say you, do I add building a 302 to my list of projects or put a couple dollars in my pocket?
Anything is steetable if you want it to be. Seems like low lift, but the RPM band is kinda high. You didnt happen to see any .050 duration numbers did you?
They weren’t visible Mike. I suppose I could take the sheet out of the package and see if they are listed underneath. I realize anything could be driven on the street, but I was thinking along the lines of a car for my son. I don’t have a problem with him having a car with a little ass, but I don’t know that I want him driving a car with a racing motor in it. I don’t want the troopers calling me to bail him out because he was drag racing with his buddies after school.
I get those feelings too Bill. And sometimes I get angry because he isn’t here to answer the hundreds of questions running through my head when I’m around the cars. Fortunately there is a good group of people here that are always willing to help. I just try to limit the stupid questions so people don’t get fed up with answering them.
Looks like what dudes used to call a 3/4 race cam. Depending on the manufacturer of the cam, and who’s talking.
It’s pretty representative of the twitchy cams that used to be used on the street with cars and trucks pretty dedicated to performance work. I wouldn’t want to drive it through rushhour in LA or ATL, but it would be okay for commuting and blasting around town.
Stick it on the shelf, unless you need the money. It won’t bring much on eBay.
As Mike has said, the lift really isn’t all that high, It’s the duration we need to see and overlap, to help with understanding what this cam can do or it’s use.
the duration is spelled out (mathed out actually) right in the provided numbers and in the cam description at the start:
Intake open 44 btdc closes 78 abdc plus 180 degrees of in between rotation equal 302.
Exhaust open 80 btdc closes 42 abdc plus 180 degrees of in between rotation equal 302.
So it is a 302 duration cam which is what the first bit of data Al pointed out was saying in code Grind # H-302
Lift Intake 302 483
Exhaust 302 483
Rocker Arm ratio 1.6
Timing 44 78
80 42
Now for the overlap add intake open to the exhaust close and you have 86 degrees of overlap. What does that tell you? 86 is going to be a bit lumpy cam in a small block ford with standard heads. The overlap is aggressive enough that low idle is lost. The scavenging affect of the exhaust is not going to be working well and will necessitate bumping the idle up to smooth it out enough to keep running. You are in the “4” range of this nifty little graphic representation of overlap effects: http://www.popularhotrodding.com/tech/0607phr_camshaft_basics/photo_07.html
The article associated with that graphic is good read for some cam tech.
Have some of Dads and Grandpas stuff. Know zactly what you mean!
Gotta add to that. I was scavenging through some cabinet bin drawers of a miscellaneous collection that Grandpa had put together. I was desperately looking for a small and unusual spring to help me finish a project. I had lost it outside. Then there is was. One lone little weird spring sitting in a pull out drawer all by itself. I could see Grandpa putting that little bugger in there thinking or even saying as he did “Never know someone might need that someday…” pack rat that he was!
I suspected there would be a way to determine the duration from the data that was provided, but it had to be left to someone smarter than me. I think I have enough info to realize I don’t want to build anything based around this for my son to drive on the street. I’ll just throw what I have on the shelf and if I run across a deal on a Comet or something similar, I’ll use it for that. Because I really need more projects. I appreciate all the info.
The advertised duration doesn’t tell enough of what you need to know. Everything you need to know can be mathemetized from the valve timing that is provided, except for the .050 duration. The only way, without a card or maybe a call to the manufacturer with the part number, is to stick it in and degree the cam. It it pretty easy, but you would need at least a block, timing chain set, at least one lifter, and a degree wheel. My guess is that it would be in the 230° to 240° range, but there is no way to tell without degreeing it.
The spring rates are not terribly high, but again, it is a rather low lift cam. I would think that it is a hydraulic cam because of the H in the grind number, so that would tell me that it can’t be too terribly radical. I would think that it would have a nice lopey sound to it, and some good umph, but nothing too crazy. The higher RPM band is likely due to the low centerline of the lobes, which does not really mean power, it just means it likes revs.
low lift/long duration is meant to make use of early sucky heads on the 302 and 289’s at high rpm.
Less total time to return valve to seat but hanging them open longer leaves more area under the curve and moves the torque peak up in the range while leaving the engine time for valve actuation at higher cycle speeds. Also lets end users buy it and use their stock bottom end. Til it blows anyway.
It approaches the mechanical limit of old school hydro lifters, and really anything much more radical would be done with solids.
compare with the K code 289 cam:
Hipo cam specs:
Part Number C3OZ-6250-C
Application: 63-67 289 HiPo (and 68 service)
Lifter: Mechanical, lash 0.019"
Intake events: open 46* BTC, 12* ATC; close 80* ABC, 26* ABC (not sure what 2nd number means)
Exhaust events: open 94* BBC, 36* BBC; close 36* ATC, 22* BTC
Duration: 310* both I/E
Lobe lift: 0.298" lobe, 0.480" valve
Overlap: 82*
It’s a pretty decent grind (the 289 hipo) that we’ve probably all heard running in a car sometime, and is where you hit the threshold of what needs solids and what doesn’t. At least in old stuff.
The old H-302 is right on the line before you step up to solids, as most of the 3/4 race cams were. Generally, the 300/.500 cams for the SBC set this standard. So, the cams for the smaller displacement (smaller than 350 inch) engines use less lift and duration to the same effect.
Of course there are no hard and fast rules and this is a fairly gross generalization regarding the two cams. So, just forget this whole post.
