Carbs, cams, time & $$

[Stevelivingfree]

Have a 72 with the 1608. She burns oil leaving a blue devil chasing me down the road. Done compression tests, etc. and they are not too bad. Ugly plugs. Figure that as a bare minimum I need to do valves and seals so I have started to pull the head. Will figure out the rest once it sees the light of day. She has a 34DFH carb. How deep I need to get into the bottom end will determine how much optional stuff I can do this winter. Current roadmap is get rid of smoke, replace suspension bushings, upgrade breaks, shocks, springs then onto engine performance.

So my question for you all. While the head is off, is it worth switching the cams for some higher performance ones. I understand that if I do not also change carb, manifolds, etc. I will not get the most out of the mods but it would be nice not to have to reopen the head when the cash comes to start changing the rest. Will it do any harm?

Also interested in your recommendations for carb & cam selection....

Thanks.

[vandor]

You'd be better off spending your money on a bottom end rebuild than cams. Cams are relatively easy to upgrade later.
Raising the performance of a tired bottom end will wear it out much faster. 1608 pistons are not easy to come by, so you might want to have some forged ones custom made that will also raise the compression.

[So Cal Mark]

if the head is apart I don't see any reason not to upgrade cams, but it does sound like you need rings at a minimum

[klweimer]

As with everything else, it's a matter of time and money. Only a zillion threads on the forum weighing the pros and cons of what upgrades to do when. I'm with vandor, that I would get the bottom end sorted out first, as cams are pretty easy to drop in later. But if you have the cash, putting in new cams when the head is already apart, is a no brainer. Set aside $200 for adjustable cam wheels regardless; well timed stock cams will run better than poorly timed performance cams.
Kirk

[carl]

My understanding is that with the low compression of a stock spider motor that hotter cams is a waste of time and money. Besides, it's easy to change cams with the head installed so no time or effort is really saved by doing cams with the head off. If you still have the 1608 intake manifold on the car then what you really want for a simple performance upgrade is an 1800 intake manifold. Next real world performance upgrade is to chuck the 1608 and install a 2L motor.

I don't remember the way to do it, but you can generally tell if the smoke is caused by bad valve seals or piston rings by when the smoke is generated, that is, only on take off or constantly, only when cold, etc. Someone can chime in here and explain.

[Stevelivingfree]

Thanks guys. Head is off & at least a couple of the exhaust valves rock in their guides. Made me happy because I thought I had found the problem.....

Had compression Dry @ 145, 145, 150, 140 & with some oil of 160, 170, 190 & 165. Measured the bores & got the following #1 @ 3.1515", #2 @ 3.1585", #3 @ 3.1475 & #4 @3.1515.

I believe nominal is 3.1500? From the numbers for #2 I am assuming I need to do the bottom end too. Anyone know of a machine shop in BC with Fiat experience? Will also need parts - any in Canada?

[Shadoobie]

Set aside $200 for adjustable cam wheels regardless; well timed stock cams will run better than poorly timed performance cams.
Kirk

I cannot emphasize this point enough. Ensuring proper cam timing made all the difference in the world for me. I kept the stock cam gears, but it's definitely something to be aware of during a build.