4.9L head

[IowaTom]

I've been told by my machine shop the cyl head to my in-line six is toast because of a crack near a valve seat. I know a local guy with a welding shop who says he can do cast iron and I'm tempted to try him first before hunting for another one - that might have the same issue. WWYD? Thanks!

[Gary Lewis]

What would the guy charge to weld it? And does he offer any guarantee?

My concern is that you could have a bit of money tied up in the welded head and have it crack again down the road. Maybe it was overheated at some point and there are stresses in it that will show up as cracks?

And have you done any searching for the price of a good head? How does that compare?

[ratdude747]

I'd look for another head. Cast iron welds poorly (if anything, it brazes a lot better, welding requires preheating and/or nickel rod), and given the amount of thermal stress near the seats, I wouldn't trust a weld or braze there on any material. Heads can be found... just make sure you get the right one. There were three varieties that I know of; 240, 300 carbed, 300 EFI. 240 will put your compression ratio too high (unless you're after that in a modified application), and EFI's combustion chambers are different (more than just adding the provisions for fuel injectors).

[IowaTom]

I'd look for another head. Cast iron welds poorly (if anything, it brazes a lot better, welding requires preheating and/or nickel rod), and given the amount of thermal stress near the seats, I wouldn't trust a weld or braze there on any material. Heads can be found... just make sure you get the right one. There were three varieties that I know of; 240, 300 carbed, 300 EFI. 240 will put your compression ratio too high (unless you're after that in a modified application), and EFI's combustion chambers are different (more than just adding the provisions for fuel injectors).

Thanks, Guys. All good information - and yeah, I thought about a "re-crack" down the road, too. I suppose it's sometimes better to make a toyota out of an old Ford cylinder head! :-)

My engine's weird in that it started life an EFI and is now carbureted. The machine shop guy knows this and supposedly what to look for in the one I might use. Still waiting to hear from him.

I'm anxious to have her running again and smoothly. Should I not post again 'til after Christmas, I hope everyone on the forum has a blessed and fun one! Thank you all for your help!

[1986F150Six]

Thanks, Guys. All good information - and yeah, I thought about a "re-crack" down the road, too. I suppose it's sometimes better to make a toyota out of an old Ford cylinder head! :-)

My engine's weird in that it started life an EFI and is now carbureted. The machine shop guy knows this and supposedly what to look for in the one I might use. Still waiting to hear from him.

I'm anxious to have her running again and smoothly. Should I not post again 'til after Christmas, I hope everyone on the forum has a blessed and fun one! Thank you all for your help!

Since the cracked head to be replaced is from a 1987+ F.I. head, consider this:

https://www.ebay.com/itm/175066594882?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20200818143230%26meid%3D80dfd938193943fd8f6e3b611ffd7615%26pid%3D101224%26rk%3D1%26rkt%3D5%26sd%3D144206113042%26itm%3D175066594882%26pmt%3D0%26noa%3D1%26pg%3D2047675%26algv%3DDefaultOrganicWeb&_trksid=p2047675.c101224.m-1

or this [bare]:

https://www.ebay.com/itm/144206113042?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=144206113042&targetid=1263094005506&device=c&mktype=&googleloc=9012676&poi=&campaignid=14859008593&mkgroupid=130497710760&rlsatarget=pla-1263094005506&abcId=9300678&merchantid=8427944&gclid=CjwKCAiAtouOBhA6EiwA2nLKH0xQgcyFrj44wnHVWKkfG3DpuBbUrDo3k1kFJCl108wCDK4U-Umc3BoCxVgQAvD_BwE

 

[FuzzFace2]

I'd look for another head. Cast iron welds poorly (if anything, it brazes a lot better, welding requires preheating and/or nickel rod), and given the amount of thermal stress near the seats, I wouldn't trust a weld or braze there on any material. Heads can be found... just make sure you get the right one. There were three varieties that I know of; 240, 300 carbed, 300 EFI. 240 will put your compression ratio too high (unless you're after that in a modified application), and EFI's combustion chambers are different (more than just adding the provisions for fuel injectors).

I got a question?

I have heard the 240 head dose up the compression but I have not seen by how much.

You are the first to say it will raise it too much.

So what dose it bump it up to that is too much?

Dave ----

[1986F150Six]

I'd look for another head. Cast iron welds poorly (if anything, it brazes a lot better, welding requires preheating and/or nickel rod), and given the amount of thermal stress near the seats, I wouldn't trust a weld or braze there on any material. Heads can be found... just make sure you get the right one. There were three varieties that I know of; 240, 300 carbed, 300 EFI. 240 will put your compression ratio too high (unless you're after that in a modified application), and EFI's combustion chambers are different (more than just adding the provisions for fuel injectors).

I got a question?

I have heard the 240 head dose up the compression but I have not seen by how much.

You are the first to say it will raise it too much.

So what dose it bump it up to that is too much?

Dave ----

The 240 and F.I. head will raise the compression approximately 1/2 point over what the 300/4.9L head delivers.

[FuzzFace2]

The 240 and F.I. head will raise the compression approximately 1/2 point over what the 300/4.9L head delivers.

So that's not much unless you are starting at 10.5:1 LOL

We are what 8.5:1 so that would be 9:1 even I dont see that as an issue.

Now I dont think I have heard of the EFI head raising the compression but think I seen it posted the chamber is shaped differently so the flame front is different, slower?

Dave ----

[ratdude747]

I'd look for another head. Cast iron welds poorly (if anything, it brazes a lot better, welding requires preheating and/or nickel rod), and given the amount of thermal stress near the seats, I wouldn't trust a weld or braze there on any material. Heads can be found... just make sure you get the right one. There were three varieties that I know of; 240, 300 carbed, 300 EFI. 240 will put your compression ratio too high (unless you're after that in a modified application), and EFI's combustion chambers are different (more than just adding the provisions for fuel injectors).

I got a question?

I have heard the 240 head dose up the compression but I have not seen by how much.

You are the first to say it will raise it too much.

So what dose it bump it up to that is too much?

Dave ----

I read this article:

https://www.foleyengines.com/tech-tip-202-ford-csg649i-ford-300-cylinder-head-differences-made-easy/