Header bolt removal

[rponfick]

I see a lot of posts on which bolts to use, but not on how to remove. I am working on a 351W with Edelbrock heads, FFR headers, and the former owner must have been a weight lifter, as every bolt is super tight. One issue I have is I thought the 6 point bolt head was 3/8", but I cant get that wrench on it. Thought maybe metric, so a 10 mm fits pretty good, but don't know if they made a 10mm bolt for headers. I am afraid to round off the heads with a 10mm, but a 3/8 doesn't fit. any advice?
Will heating or some Blaster help? As everyone knows, getting a wrench in these things is a chore.

I would hate to remove the heads just to get the headers off. I got two bolts out, which only leaves 14 to go.

Thanks,, Ralph

[egchewy79]

how old is the engine and how rusty are the head bolts? I'd try some PB blaster first and clean any corrosion/rust/dirt off the bolt heads. Are the bolts you removed fitting in the 3/8" socket?
Have you removed the valve covers? that might buy you some additional room to work.

[rponfick]

how old is the engine and how rusty are the head bolts? I'd try some PB blaster first and clean any corrosion/rust/dirt off the bolt heads. Are the bolts you removed fitting in the 3/8" socket?
Have you removed the valve covers? that might buy you some additional room to work.

Engine is only two years old with only 1100 miles, so no corrosion issues. The bolts don’t fit in 3/8 wrench, but maybe a rounding off is from installation. Metric 10mm fits, but maybe a little loosely. Valve covers are not in the way, so not a problem.
Ralph

[jts359]

Make a 50/50 solution of atf and acetone in a spray bottle and spray it on " But " first if possible use heat on the bolts and when you put it back together apply never seize to the bolts , Ed

[Papa]

Header bolts only need 20 ft.lbs., but stainless bolts into aluminum heads can corrode and seize up. PB Blaster should help. Figure out the right size for those 12-point bolts and then go buy a sacrificial box wrench and grind it to fir the clearance. I had to do this with a couple of bolts on my intake.

Edit: Sorry, somewhere I thought you mentioned 12-point, but that was in my head. The same advice is what I'd give on grinding a box wrench that fits to thin it down so it can get on the bolt. No luck with a socket?

[Railroad]

Look to see if the bolt heads have a set screw in the middle of the head. If so these need to be backed out.
Are there any tangs coming off the head of the bolts? These may be held on with E clips. Remove both.
How about a picture of the head bolts.
good luck,

[rponfick]

Look to see if the bolt heads have a set screw in the middle of the head. If so these need to be backed out.
Are there any tangs coming off the head of the bolts? These may be held on with E clips. Remove both.
How about a picture of the head bolts.
good luck,

Photos.
193510193511

[Mike.Bray]

I had a bolt one time in a turbocharger that would not come out and was starting to round over. My father came out, handed me one of his two Snap-On wrenches and said "Try this". It came right out! He explained to me about Snap-On's flank drive design in wrenches and sockets and how they worked so well. All of my wrenches are now Snap-On (at the expense of my daughter's college tuition). If you can find a Snap-On wrench you'll get them out without rounding the heads off.

[idf]

I had a bolt one time in a turbocharger that would not come out and was starting to round over. My father came out, handed me one of his two Snap-On wrenches and said "Try this". It came right out! He explained to me about Snap-On's flank drive design in wrenches and sockets and how they worked so well. All of my wrenches are now Snap-On (at the expense of my daughter's college tuition). If you can find a Snap-On wrench you'll get them out without rounding the heads off.

I would also suggest using a 6 rather than 12 point wrench.

[OSU Cowboy]

My header bolts use a 7/16" wrench. They also have an allen head in the center of them ... might be an option for you.

[rponfick]

My header bolts use a 7/16" wrench. They also have an allen head in the center of them ... might be an option for you.

Thanks for the suggestion for replacements, but, for now, I just want to get these stupid old ones out.

Ralph

[egchewy79]

Thanks for the suggestion for replacements, but, for now, I just want to get these stupid old ones out.

Ralph

i think he was trying to suggest a 7/16" wrench, but this would be way too big as 7/16">10mm.

[rponfick]

i think he was trying to suggest a 7/16" wrench, but this would be way too big as 7/16">10mm.

Yes, 3/8" should be what fits, but it doesn't. 10mm is close, but a little loose. I have ordered some 10mm six-point sockets to see if they do not round off the bolts, but loosen them.
Let the fun continue.

Ralph

[rponfick]

I have determined the bolts are 3/8" and some rounding during installation caused me to think they were 10mm. I have managed to use a small hammer to force the 3/8" wrench/socket onto the bolt head. I am not completely there yet, but getting closer. Some of those bolts are a real pain to get at, and it is good to take a sanity break.
Thanks, Ralph

[Papa]

I have determined the bolts are 3/8" and some rounding during installation caused me to think they were 10mm. I have managed to use a small hammer to force the 3/8" wrench/socket onto the bolt head. I am not completely there yet, but getting closer. Some of those bolts are a real pain to get at, and it is good to take a sanity break.
Thanks, Ralph

If you remove the valve covers, the bolts are much easier to get at.

[rponfick]

I have determined the bolts are 3/8" and some rounding during installation caused me to think they were 10mm. I have managed to use a small hammer to force the 3/8" wrench/socket onto the bolt head. I am not completely there yet, but getting closer. Some of those bolts are a real pain to get at, and it is good to take a sanity break.
Thanks, Ralph

I have to revise my previous comment about the bolts being 3/8". I got my new 3/8", six point wrench yesterday and happily assumed my task was near completion. Alas, the wrench would not fit over the bolt heads, even with some tapping from my brass hammer. I was totally bummed.

So, I decided to take some measurements. 3/8 is .375". I measure a spare 3/8" bolt head, and it is about .372". The bolt head on my header bolts are about .387-.389". 10mm is about .394".

I have concluded that the engine builder used some cheap Chinese bolts, which the manufacturer aimed at 3/8" or maybe 10mm. Who knows?

I am now awaiting a six-point, 10mm wrench.

Ralph

[egchewy79]

ever consider one of those gator grip sockets w/ the retractable pins in the socket head? I know user results may vary, but could be helpful.
header bolts shouldn't be THAT tight.

[rponfick]

ever consider one of those gator grip sockets w/ the retractable pins in the socket head? I know user results may vary, but could be helpful.
header bolts shouldn't be THAT tight.

chewy79 thanks for the idea. I think those socket heads are a bit to fat for header locations. You have to dent the headers to get regular socket/wrenches to fit on some. And you are correct, they should not be that tight.
Ralph

[mburger]

Once you get them out, I would replace them with Stage8 bolts and Remflex gaskets. Torque to spec and never worry about retorquing them or messing with them again.
Also, while it seems the valve covers are not in the way, once you remove them you’ll suddenly have lots of extra room to work and to see the bolt heads.

[rponfick]

Mark, thanks for the parts suggestions.
I was finally able to get the remaining 7 header bolts out today. I had to grind off a little metal on my new six-point 10mm wrench to get it on a couple of bolts. I tried to dent the headers to provide more room, but that was impossible to do with the headers on the car, and with little room to maneuver the hammer and punch.
I am glad this chore is over and I can proceed to pull the engine and install an Edelbrock 2090 top-end engine kit (CnC heads, air gap intake, roller cam, lifter, pushrods, gaskets, timing chain, etc.
Let the fun begin.
Ralph

[mburger]

Mark, thanks for the parts suggestions.
I was finally able to get the remaining 7 header bolts out today. I had to grind off a little metal on my new six-point 10mm wrench to get it on a couple of bolts. I tried to dent the headers to provide more room, but that was impossible to do with the headers on the car, and with little room to maneuver the hammer and punch.
I am glad this chore is over and I can proceed to pull the engine and install an Edelbrock 2090 top-end engine kit (CnC heads, air gap intake, roller cam, lifter, pushrods, gaskets, timing chain, etc.
Let the fun begin.
Ralph

Wow that sounds like she's gonna be a handful!
Have fun with it!