Hypothetical question.
If a head on an inline 6 is warped and milled down the cylinders 1 &6 would have a higher compression ratio than 3 & 4. Would this be an issue?
Head needs .025 off each end to flatten it back out.

 

that's not how it works when you mill the head

assuming the head had enough material, the shop would takes slices of material out until the entire deck had been milled and every edge was same thickness. they wouldn't take 0.025" from the ends only. and if they do, I suggest a different shop

end result, each cylinder will have the same material left. however, that's a ton of material to remove. I'd be surprised if you didn't have valve clearance issues with the piston after that

check with the tech manual for that engine, and also have the shop give you a final amount of material removed to level the deck. IMO, I'd go with a new or new to you head (junkyard). even if everything fits fine afterwards, your compression ratio may not make it worth all that effort

 

I really know nothing about how they mill a head. When they showed me the head with a straight edge on it we were able to slide a .025 filler gauge under it.
The head would need new valve guides and all the seats redone and on and on ...
The machinists said it could be milled but I wasn't sure what would happen if it was.
I'm already searching for one
I have a boat anchor (4.9 head) for sale
🤣

 

how much do engines run in your neck of the woods? running engines in decent shape are $250-500 up here. replace all the gaskets and you should have a decent engine without leaks that'll get the job done for a few years

especially your 4.9, those things are usually indestructible. how'd you warp that head?

 

.025 off head and valves hit pistons?
Then how come when the timing gears go and some valves are full open and pistons still move they don't hit? I would think it would take more than .025 off the head to cause that.


Now have a high(er) lift cam and all bets are off.
Dave ----

 

I've found a few engines down here in $500 range.
Bought truck and was just going to replace gaskets and maybe bearings. Since I had the head off I thought to get it checked. No clue how it got that hot and warped.
A whole head at Auto Zone is cheaper than they want to charge for all the work this one.
I learned that the truck should have EFI and not the 1bbl carburetor so I'm questioning what I plan to do to it.

 

EFI, I'm pretty sure that didn't come about on the 6-banger until 1987+.

 

I personally would get another engine before slapping a new head on it.

that way you can pull the oil pan, check her over and do some basic preventative maintenance. clean pickup filter, new oil pump, check the bearings...etc. then completely reseal to avoid the inevitable damn oil leaks these trucks are plagued with after all the years.

a few hours and bucks here can pay real dividends. that, and you don't know how the hell the prior owner warped that head. You may have other underlying issues that'll surface shortly
I don't know the specs on this engine. Note how I said as much above.

I do know that other engines that much can definately cause issues. Hell, just a few thousands shaved and using thinner gaskets can cause contact for some motors

 

I didn't think they did. I got that from Gary's decoder And when I look for parts they always ask about the 8th digit. I have a Y
BTW thanks for the link

 

I'm definitely going to look for a new / newer engine. This is supposed to be kind of a project to keep me busy on my time off so I'm not in much of a hurry. Just impatient. lol
I have tons of work to do on the interior and just want the engine part over and done with 🤣

 

The book is slightly misleading there @Gary Lewis

Y means only a 6-banger in my memory, so I went and looked at the what the book is saying....

Available from 1983 forward... 6-cyl gasoline-fired 4.9L 300 cid engine... with EFI.... that EFI part is somewhat misleading to the clueful, downright wrong to the newbies.

Somewhere in the mid-80s (certainly by 1985) Ford starting migrating to computer-controlled engines, and a few model years had computer-controlled carburetors. Your engine is one of them (the 302 is the other).

True EFI didn't come in these things from the factory until the next generation.

What year is this truck?

 

Yes, Y only meant the 300 six in the 1983-86 timeframe. And EFI wasn't available until 1987. So, I edited my version of the catalog as well as my site. Good catch, and thanks for the heads-up.

Engine Codes - ???Gary's Garagemahal

 

Thank you, Gary! Notice how there's no 1FB or anything similar to describe a computer-controlled carburetor.

 

Truck is an 84.
Thanks for clearing that up for me.

 

My son has a 1984 and I have a 1986 F150 with 4.9L. Both were carbureted with the feedback system.