I recently bought a "core" engine for a mild rebuild. Not much in the area in my area and the price was doable. I got the heads, ***embled block, intake, etc for $200.00 US. It was noted it ran good, mild exhaust note, but puked oil from every orifice. (I suspect the reason was the oil ventilator was missing from the valley pan and it had closed valve covers) I hoped to do only rings, bearings, oil pump, timing components, and a deep cleaning, keeping the cam and lifters. From what I can guess the engine is a 65-67 283CI SBC, 2Bbl. During the tear down I discovered it is a 30 over block with forged pistons and no noticeable wear on the cylinders. It has an aftermarket camshaft that I suspect is a copy of an L79 grind. The cam has 274 H2 stamped on it's rear and no marks on the front. It has 1539 on the shaft which I ***ume is the cam billet or core number. I have not measured the lobes yet but will post the results when I do. Does anyone recognize the markings of the cam? Any guess on the compression ration with these pistons and standard 283 heads?
Hi Moedog , You’re right ,,,that’s the cam blank casting number,,,,,,but I think it looks like 1529 . The other numbers remind me of some old id numbers from cams I’ve owned . But,,,they usually marked the cams with a few letters to i.d. The manufacturer . Sorry I couldn’t help,,,,,Oooh,,Raaaa . Tommy
I had a Crane Ford cam that had that same marking, 274 H2, or it might have been 272 H2, can't remember for sure. H2 was the second version of that grind. Mine was something like 272 duration with .512 lift IIRC. If you could find somebody with a few older catalogs you might be able to run it down.
My guess is the 274 is total duration. Subtract approx 50 degrees for the duration at 0.050 lift, gives around 224. That will be a mid performance cam in a 283. For example the fabled 327/350 hp cam has 222 degrees at 0.050 lift.
I ***ume this is just a curious question about the cam? So clean a valve relief out and CC it the x4. Put a dial indicator on the piston at TDC and see how far it is in the cylinder. Then look at the head gasket you want or will use. Plug the numbers into one of the many CR calculators. Once you know the CR you can then look to select a cam that works properly for the engine and your intended use. Just my thoughts. Hydraulic flat tappet cam and lifter sets are not very expensive.
Messing around on Google. I can't find an exact match. Based on the last 3, I'm leaning towards 327 300 hp cam. Good luck with the search. Crane 274 H06 Lift 0.450 / 0.450 in, Duration 274 / 274, 106 LSA, 1800 / 5800 RPM Comp 274H .552/.556 274/286 duration These 3 aftermarket replacements: TRW TM274 Sealed power CS 274 Wolverine CS 274 Dur @ .050 In. 194 Ex. 203 Lift .391 .410 This is basically a 327 300hp cam. 1529 is a cam core number, can you find CMC or CWC in the cam anywhere. CWC is the foundry, CMC is a grind company that did a lot of factory reproduction grinds. https://www.jalopyjournal.com/forum/threads/cmc-camshaft-1539.351815/
Not excessively,,,,,the lobe still has a nice peak to it . Looks like typical wear after break in and use . Tommy
Budget36 it is not much more than a riddle to be solved. What was the cam grinder attempting to say to us with these markings. Carpok it has hydraulic lifters.
I went thru crane catalog pages 40 or so. https://issuu.com › docs › crane_ca... Web results Crane Cams Master Catalog by Crane Cams - Issuu They have a similar format H 272 2 in the catalog, may be stamped differently on the cam. But I don't see an H 274 2, there's a few cams with 274 but they are different series. Z, H10 etc. Not H2
That is the numbers that I expect to find when I check it. (.450 lift) I slid the cam back into the block for storage and protection. If at all possible I'll pull it again and check the measurements this week. I actually have ran that Crane cam (100172) you posted in my last A Model sedan. I had it in moth balls for years and put it in an almost stock build. It was a nice cam in a 350 SBC.
Similar story I just revived mine from the storage shelve and put it in a fresh build for my 57 stepside. It’s a great cam and has a nice lop at 700 rpm.
Okay, today I put the rotating ***embly together and while I was busy I measured the cam lobes. Base circle of the camshaft appears to be 1.258 by digital caliper. Lobe height appears to be 1.525 by digital caliper. Is this math correct to obtain the lift number? 1.525 - 1.258 = 0.267 x 1.5 = 0.4005 (lift?) No other stamped or engraved numbers were found on the camshaft.
Approx .400 lift Lines up well to a 327 300hp cam and many aftermarket companies use 274 in the p/n for this grind. Here's a thread on factory performance cam specs for reference and some popular aftermarket grinds If you're looking for something else. https://www.jalopyjournal.com/forum/threads/gm-factory-cams-specs.1227162/ You don't need a lot of duration with a 283 vs a 350. The cam will act bigger in a 283.
No personal experience with the 327/300 cam in a 283, but what a mild cam in a 350. Hope it's better in a 283. Just saying you could do a lot better IMHO.
Probably so... It is a 66-67 truck 283 - 195 hp from what I can tell. I have a pair of heads from a 283 powerpack that were rebuilt nicely and stored a few years ago. I had a sudden change in that build (or in life) and didn't use them. They were heavily oiled, bagged and stored. I will pull them out and see what the casting numbers are and how they look. Maybe they will be better for compression but I doubt it. I haven't really inspected the heads from the 283 being currently rebuilt but I know they will need valve seals to start. They seals were crumbled and ****tered within the oil returns of the heads.
Update on the camshaft/engine. The heads were gone through and had one valve that looked off. It was replaced along with the valve seals. The springs checked out good and were retained. I suspect they were common Z-28 springs. That dammed water pump was replaced with a new one. I still have no clue on make or manufacturer but rebuilt engine lasted at least two 20 minute sessions on the test stand. It had good oil pressure, ran at a good temperature of 180° to 195°. It doesn't idle all that well but that's due to the off the shelf demon carburetor I keep around that never idled well since new. (The carburetor has served years of road duty and test stand duty) The carburetor lives in a state of purgatory getting a drink of gasoline every so often as it leaves its cardboard box then returning to the box on the shelf until the next engine build. A new carburetor should be arriving today for the engine.
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