C3 big block head removal

[Tom L.]

Unfortunately the valve guides on my car are done. I'm in the process of removing the heads. I've run into a few obsticals. First, getting the drivers side exhaust manifold off. Seems a bunch of stuff has to be moves out of the way. Also, the steering box, (one of the things that seem to be in the way) has a few things that hamper it's removal.

Any help on this project? Especially the manifolds and steering box. As usuall, thanks in advance.

[Lyndon S.]

Re: C3 big block head removal

I never done a 454 in the car. But I can tell you that when you take your heads to the machine shop, to have them cut the heads for Teflon valve steam seals. And you will not have any more problems after having that done with the seals anyway. You might could come down with the manifold under the car instead of trying to come up with it?

[Tom L.]

Re: C3 big block head removal

Exhaust is still in the car. I'm avoiding removing it so that isn't an option....for now.

Teflon seals have already been discussed with the machinist, got that part covered. Just need to get them to him.

[Bill C.]

Re: C3 big block head removal

Is your an AC car?
Does it have PS ?

If the answer is yes to the both -- good luck......

I did the PASS side exhaust manifold on my car - way back before the resto - and I had to remove the front pipe and the entire AC compressor assembly/brackets to get it out - from the bottom only.

Can't speak for the DVR side. But I am pretty sure, through the bottom also.

As for getting your heads off - if the car is AC, damn near imossible. There are a couple head bolts that are so tight near the evaporator box.



If it were me - I would pull the engine/tranny assembly from the car and work on it that way.
Be way easier to cleanup/refresh and reassemble.

[Jim M.]

Re: C3 big block head removal

Hi Lynn: passenger side exhaust manifold goes out and in from underneath, and you must take a/c compressor off if so equipped. Driver side manifold goes out and in from above and it is not necessary to remove steering box. If you go with "positive" valve stem seals, the odds are you will have a huge oil consumption problem. Use the "umbrella" seals like Tonawanda did. All this is entirely possible with powertrain in the car as I have done it. Regards, Jim

[Gene M.]

Re: C3 big block head removal

Make sure to have machine shop seal up the new cast iron guides good when pressed in. The proximity to the water passages is close with any corrosion in the casting. Do not get talked in to aftermarket racing guides, not a long life on the street. If all work is done correctly you should not need any special valve seals. New valves and grind seats is a definate and only way to go when replacing guides.

[Clem Z.]

Re: C3 big block head removal

i have posted before about not removing the original guides because they are drilled after they are installed and the bore in not centered in the guide. just bore out the original guides and install giude liners or you could have a problem with a valve seat in the head that is way off of the original valve seat. been there done that back in the day

[Dick W.]

Re: C3 big block head removal

Agree with Clem. Do NOT replace the guides. Have bronze guidliners installed. Two reasons, the old guides don't leak and new ones can possibly leak (been there done that) and two, as Clem stated chances are the new guides will not center the valves on the seats. Not my favorite thing to install new seats in cylinder heads.

[Tom L.]

Re: C3 big block head removal

Bill, Yest to A/C and P/S and they've both been removed. Getting the pass. side out throught the top was no problem, just the drivers side.

Jim, The car also has power brakes, not sure how the manifold will get past all that stuff. I've wiggled it around with no luck. Not sure what you mean by "Positive" seals.

Gene and Clem, the entire guide will not be removed, they will be bored and sleeved. Once the sleeves are in the valve seats will e ground off the new guides to insure proper alignment.

[Gene M.]

Re: C3 big block head removal

......................

Gene and Clem, the entire guide will not be removed, they will be bored and sleeved. Once the sleeves are in the valve seats will e ground off the new guides to insure proper alignment.

Original guides in bb is sams as sb a bored, reamed holes in the cast iron. They don't press out.

But bronze is not a good choice for the street. A machinist SHOULD be able to bore for guide, press, ream, and maintain center. But seats will still need to be ground with new guides. We are talking thousands of an inch and if machinist can't maintain that go somewhere else.

A point of good advice is use one piece valves not welded two piece. Pay attention to materials selected as bronze can transfer material to stainless valve stems. Initial lube is critical.

You have a lot of opinions here, so do what ever gets your fancy.

[Clem Z.]

Re: C3 big block head removal

Original guides in bb is sams as sb a bored, reamed holes in the cast iron. They don't press out.

But bronze is not a good choice for the street. A machinist SHOULD be able to bore for guide, press, ream, and maintain center. But seats will still need to be ground with new guides. We are talking thousands of an inch and if machinist can't maintain that go somewhere else.

A point of good advice is use one piece valves not welded two piece. Pay attention to materials selected as bronze can transfer material to stainless valve stems. Initial lube is critical.

You have a lot of opinions here, so do what ever gets your fancy.

the guides in BBC heads both cast iron and aluminum are installed in at the factory as a seperate piece. SBC cast iron heads the guides are cast in at the factory

[Thomas H.]

Re: C3 big block head removal

Bill, Yest to A/C and P/S and they've both been removed. Getting the pass. side out throught the top was no problem, just the drivers side.

Jim, The car also has power brakes, not sure how the manifold will get past all that stuff. I've wiggled it around with no luck.

Lynn,

I removed the heads from my LS5 PB car before I removed the block. I was expecting just to do the top end, but one thing led to another............

I remember the dr side being a bear. If I remember correctly, I ended up removing the engine mount bolts and lifing the engine a bit to facilitate removal of the manifold. I don't think there is enough room to get at the lower head bolts by just moving the manifold back and forth. I did this back in 06 so my memory is a bit weak, but I do believe I lifted the engine to gain clearance.

Tom

[Dick W.]

Re: C3 big block head removal

Original guides in bb is sams as sb a bored, reamed holes in the cast iron. They don't press out.

But bronze is not a good choice for the street.

I have used the bronze guideliners since the late '60's with no problems other than one machinist (me) error. Never had any premature wear problems.

I know for a fact that the guides are pressed in a big block. I got a wild hare up my .... and replaced all sixteen in a 454. Ended up pulling both heads back off because of water leaks around the guides.

[Tom L.]

Re: C3 big block head removal

OK, got the manifold out. just took the bolts for the steering box out and there was enough wiggle room to get it out.

I started to take the head bolts out, ouch! just throwing it out there but if anyone has removed and replaced the heads on a BB car, how did you get a touque wrench on the rear most bolts. Just asking. I'm starting to think that Bill C. might get his way.

[Rich C.]

Re: C3 big block head removal

OK, got the manifold out. just took the bolts for the steering box out and there was enough wiggle room to get it out.

I started to take the head bolts out, ouch! just throwing it out there but if anyone has removed and replaced the heads on a BB car, how did you get a touque wrench on the rear most bolts. Just asking. I'm starting to think that Bill C. might get his way.

Indeed, I managed to REMOVE the heads on my 454 with A/C and P.S., after gouging the evaporator case badly! I don't see how you could ever get a torque wrench in there to reinstall! Ended up pulling the block!!! Strange I don't remember the drivers side head being an issue to take off, just the passenger. My back hurts just thinking about it.

'73 LS-4 454 owned 21 3/4 years