Hardened seats [Archive] - Team Camaro Tech

: Hardened seats

Apr 2nd, 03, 03:45 AM
I am rebuilding the 283 engine that is in my 66 chevy c20 pickup. I just bought some rebuilt heads for it. They are 461 double humps with 194 and 150 valves. The question I have is what can I do to keep the seats from recessing, without putting in hardened seats? The truck is just going to be a daily driver. The rear gears in it are 4.56, so i know it will run down the highway at high rpms. The factory heads I took off. had the two middle exhaust valves on both heads were recessed quite badly. The orignal, engine had either 100k miles or 200k miles.

Apr 2nd, 03, 04:48 AM
I run "old fuelie's" w/o hardened seats on my '68. I put a can of Bardahl's "Instead-o-Lead" in with each full tank of gas. This is a sulfur based product that cushions the valves much like the lead in the old fuel used to. I've got quite a few miles on these heads now with some pretty evil springs! (>300lbs open load) and no damage yet. The stuff is cheap too, about a buck a bottle around heah!

Apr 3rd, 03, 03:31 PM
Te other pdq is on to something b/c I have heard/read that Marvel Mystery Oil will do about the same thing when a bottle is ran in each tank of gas.. But I couldn't get them to verify it...

I do figure that a good brand of "Top-Oil" IS good stuff! Both in the oil AND in the tank every so often... pdq67

Apr 4th, 03, 03:02 AM
If you got over 100K miles on one valve job you are doin' OK smile.gif

You can run about 2 tanks of leaded racing fuel/premium unleaded blend after a valve job and probably be fine after that. I would think about replacing any valve seats that are worn too deep but not replacing them all. You risk ruining a casting with each seat you install. With those gears and lots of use it will realy test the longevity of those seats but they will run for quite a long time without hardened inserts. Replacements will be available for some time long after we are gone ;)


Apr 6th, 03, 11:12 AM
Ive got over 220000 mile on a stock 350 chevy engine with soft seats. I dont do anything extra to it, when it was new it ran leaded gas. Im very happy with it being 33 years old. I think people over do the hardened seat deal, I think soft seats are fine for a dialy driver. Why 4.56 gears??? That ruins the dialy driving imo.

gene stills
Apr 6th, 03, 11:55 AM
I would look around for a set of 601 305 heads for your 283.They have hardened seats and are cheap to buy.Not to belittle prior post,but Iv'e had the same problem with exaust valves sinking up in the head(seat problems)with the leaded fuel heads.For a daily driver I wouldn't even think about running the eariler heads,unless the exaust seats were updated.Cost of that compared to later heads or even aftermarket heads wouldnt be worth it unless you were building a numbers matching car that you were driving a lot. graemlins/thumbsup.gif

Apr 7th, 03, 07:24 AM
I am runnign 4.56 gears because that is what they are from the factory. Also gears for this pickup are hard to find, and are also quite expensive. Thanks for the info about the fuel additives.