Performance cam recommendations

[ebrown0104]

Well, after about two weeks of ownership, I've torn off everything in the engine bay minus the radiator and timing setup. Now, the flange that holds the radiator cap cracked and fell off, and after unsuccessfully soldering it back together I need to remove my rad and either have to professionally fixed or replace it with an aluminum one. So while it's out, I'm doing a new timing belt and front seals (since I don't know when it was changed), and I figure now is the time to replace the cams while I'm 90% of the way there.

Currently, my car is a stock 1800 (1977 California with all emissions removed except the cat) with a Weber 32/36DFEV and Plex ignition. Eventually I'm going to do 9.5 or 10:1 pistons (stock size), ported head, 4-2-1 header, 2-1/4 exhaust, light flywheel, and maybe IDF's (mainly cause they look cool). I've done some searching and I'm deciding between the Allison 285V street and the 284V stage 1. I know that currently the 285 is going to be a better cam, but with everything else done I think that it may not be aggressive enough. I'm also worried that the 284 might be too big for a stock engine and will run poorly until everything else is done.

I'm also thinking of just adding adjustable cam gears to the stock cams. Is there any benefit to that, or should I just step up to better cams from the start?

As usual, thanks for any help!

[seabeelt]

Check out mark Allison's parts page. He has a good scenario and description of cams that he has for sale.

[baltobernie]

Also ask him about the adjustable cam wheels. Their purpose is not typically to increase performance, but to ensure that your aftermarket cams open and close exactly when they're supposed to. Mark will be able to tell you what his cam customers have experienced re: timing.

[sgkent]

what state are you in?

IMHO if you are subject to smog your HC will go sky high if you go much past a stock cam. The cams you can use will be a single profile - which means whatever you gain on the high end RPM you lose on the low end RPM. The most restrictive areas of making a fiat 124 engine perform have always been the induction system and exhaust. Isky used to grind all our cams when we raced in FP. PBS did my GP cams but I doubt if Isky has a grind anymore, and I have no idea if either of the Swensens are still around or their Fiat cam notes still exist. They moved into performance transmissions. What comes stock in a 124 is not a slouch for a general street cam. IMHO 285 degrees is going to be a crappy idle and the unburned fuel will eventually ruin your cat. From memory only the stock cams are like 276/272 or something like that (it has been 35 years since I looked at those pages). The 290 to 300 range and above is mostly for the track. Most single profile cam cars - 270 to 275 total duration (not measured at lift) is perfect for a street car that wants performance from 2500 RPM to 5500 RPM. 285 will be maybe 3000 - 6000 RPM but you may need to get rid of the catalytic so it doesn't overheat from unburned fuel at idle. Think about what you want to do with this car. Is it going to the track? Just looking for something well made and good performance? I think Leland's 1971 1608 ran 280/280 and 10.1:1. Of course we could get non-alcohol fuel that was 95-96 octane then too. My Acura RL with VTEC valve timing and a knock sensor burns premium only and has 11.2:1 compression. The 2016 MDX is 11.6:1 compression. That is almost unfathomable without a knock sensor and computer to regulate the burn, which a 124 won't have the luxury of. On an older engine like that unless you want to burn racing fuel 10:1 is about the max using 91 to 93 octane (R+M/2). If you can delete the cat and tolerate the lumpty lump at idle then do the 285 and you'll have a very fast street car and medium fast track car. Really have to decide how you want to drive it before buying the camshaft and setting the compression ratio. There is not a lot of porting to do with cross flow heads. Swirl polish the valve backside will help quite a bit. We used to get 9,000 - 10,000 RPM from the progressive carbs by a tweak here and there plus a little porting under the carb. Also clean up the slag on the venturi and take any rounded surfaces down to help with air flow. That of course is an open exhaust and air horn instead of air filter.

[So Cal Mark]

I've gotta disagree. We build many engines using our 285 grind and they all pass Calif smog tests and idle well at 1000rpm.