Technical SBC heads non harden seat's will they work or not

put a set of fresh 283 power pack heads on a buddy's 305 daily driver, about 6 months later we had to pull em, they sucked most of the exhaust valves up a good 1/8" or more. he knows very little about motors so he just drove it till it laid down then i had to help again.

 

We all need machine shops to make money. Maybe not for work that isn't needed but every talented honest craftsman deserves to be paid. Packard blocks are more like cast steel vs cast iron. I advise all my Packard clients to never put seats in their blocks. SPEND that machine shop $$$$ where it's needed. Same with doing the body, do you fix the 1 bad piece of wood or re-wood the whole fuckin car for an additional $20K added to the cost? It might surprise you how many think do it all. Context. Maybe I didn't feel the need to elaborate. Maybe an occasional splash of leaded fuel in a seldom used engine is enough. Hey gimp, I gotta get paid too. I'm also in the "choir"...

 

I will keep that in mind for the next (never) time that I have a Packard engine built.

My $150 is well-spent protecting the often up to $10K that I spend on having engines built.

 

I probably had better qualify my earlier statement here. If I had a set of heads at the machine shop, I would almost certainly go ahead and have hardened seats installed, at that point the extra cost would be well worth the benefits. Would I tear a nice running engine down to merely have them installed? No, I would not. One more thing to ponder, if applicable, and that is will the next purchaser be looking for those hardened seats?

 

^^^^^ As is, all sales final.

 

I’ve never had “receded valves” I assume the contact area on the valve and the seat begin to “go away”?

 

VP racing fuels madditive octanium is what it's called.

 

I put probably 5000 miles on my '39 Chev coupe last year. And if I'm having heads done they're getting hardened seats, and SS valves. It's not that much more money to have all the seats and valves done. Last set cost me $500 for all seats, valves, guides, and D&T for screw in studs.

 

Buy you’re supposed to buy new heads It’s cheaper

 

Yeah man, heads with soft valve seats are traditional!

 

A co-worker gave me a couple sets of sbc heads a couple years ago. One was a new set of aluminum aftermarket performance heads and the other was a set of power pack heads that had been ridiculously hogged out and had 2.05 and 1.60 valves in them. I sold the aluminum ones and took the power packs to the machine shop to get them rebuilt. I'm sure I am an idiot, but it will be much easier to claim stock 283 with the power pack heads than the aluminum ones.

 

While I understand replacing them if you are having work done anyways, I would as well. If the existing seats are good I don’t bother, must be laziness as I can do them myself!! I’ve yet to have a problem and I don’t use any additional additives in the gas. That certainly doesn’t mean that problems don’t happen…

 

A guy around here who machines blocks (apparently for industrial contracts) didn't recommend hardened seats for an 8BA. Quite a bit different than a SBC though. Some would swear by them but others swear by added center cap supports.
Incidentally, again only on flatheads, of the 4 or 5 I've got and even a couple bangers, I have yet to see sunken seats. I've seen them in magazines which is why I added the hardened seats in the mid 80s to SBFs.

 

As to older machine shops quiting money. I have a Kwik Way bar and compete with rebuilders that have machines that can do 10 or more engines while do one. Down to doing my own stuff or some sleeveless tractors where I can bore the block in place.

 

???? What are you referring to with "others swear by added center cap supports"? I don't see how adding hardened seats, and SS valves to a SBC would include "center cap supports"? Unless you're referring to later center bolt valve cover type heads?

 

Yes, the seat is impacted by the valves, with no lubrication from lead in the fuel the surface of the seat distorts and the valve moves up into the seat area.

On natural gas engines this is a common problem, as there is no liquid in the air/fuel mixture, nothing to lubricate the valves at all. So the engine oil for natural gas engines is formulated with specific amounts of "ash" in the oil which forms a layer of soft deposits in the combustion chamber to cushion the impact of the valves into the seats. Too much ash and the deposits will prevent the valves from seating all the way, leading to torched valves (really nasty!). Too little ash and the valves will recede into the head. Part of periodic maintenance is to check and record the valve recession, and when it gets to a certain point it's time to pull the heads and have the seats replaced.

 

These heads are power pack heads with NO accessory holes-- What type head can I replace these with that still has 64 CC and has accessory holes in head-- Thanks

 

Research 305 heads since the only ones I look for are 416’s that have a smaller chamber.

 

Exhaust valves especially under heavy loads for a period of time get very hot and when the valve is closed they try to stick together when the valve opens small amounts of the seat tends to be pulled loose and burn up. Tetraethyllead acted as a lubricant to keep them from sticking together.

 

The early 3rd Gen F-bodies had 350’s with 64cc heads and perimeter bolt valve covers I recall, don’t remember the numbers. The ‘87?-up used center bolt valve covers. I’m sure there are others though.
I think the 416 heads were 58? CC’s.

 

1971BB, Whatever is wrong, you win, my friend.
I mean many building a FH would swear they need hardened seats but don't add center main support. No biggie but some things(mods) take off as absolutely necessary when they are not the achilles heel at all.
Many examples given here but most are not examples of significant unhardened valve seat failures.

 

I don't doubt that this has been answered but just in case they make some stuff called Instead of Lead. Last I checked it was a little pricey at least for a car you actually drive. I have used Bardahl Top Oil (also called top end oil in different brands) and it works well. Or if you really want to break the bank they make some stuff for alchy burners that you can use, you can even get it in different aromas. LOL

 

I had no idea about a different oil for propane engines, this spring I’ll look for the proper oil for my forklift.
Only thing I’d ever heard (about propane engines) is they do have hardened exhaust seats.
Thanks.

 

041, 186, 292 or get some Dart Iron eagles

 

Actually I was referring to large natural gas engines, like those used to generate power. But yeah, I guess propane engines may have similar concerns, but I think propane engines just use standard engine oil formulations same as gasoline engines.

 

Most propane engines had hard seats installed because most were truck or pickups.

 

Yep! 57 er 58 cc's....

 

Any of the SBC heads from the 1970's, and even some late 60's will have accessory holes. But there are all sorts of brackets sold to allow you to mount alternator, power steering, etc. off the water pump and header bolts with heads that have no accessory holes. So you don't need to change heads to make this work.

 

They actually were not really popular for the general public until the gas crisis and by then the big 3 was selling no lead compatible motors to the general public. There was a time that the only leaded gas being sold was Ethyl (premium). Lead as a cushioning agent was never an issue until engines started having higher seat pressures. Higher lift cams required stiffer springs, which lead to higher seat pressures.