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65 Monza Head removal
Posted by: Tony Trans Am ()
Date: October 10, 2018 01:11PM

Replaced the o rings only to discover one head stud has had a helicoil repair that’s bad so need to pull head on one side. Can this be done without having to remove engine. I know most like to pull the engine but seems a bit extreme to repair one stud.

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Re: 65 Monza Head removal
Posted by: Lane66m ()
Date: October 10, 2018 01:53PM

Yep. Remove rockers and remove pushrods You may need to remove a few push rod tubes to get push rods to come out with the tubes. Loosen up all hardware, then remove all hardware. Persuade head to come off, but try to leave cylinders on pistons. You might have to devise a way to restrain them in place. Don't want to mess with base gaskets and piston rings.

Al Lane
Ellabell GA

1966 Monza Coupe, 110 hp, 4 Spd
1968 Camaro SS Coupe 350 CI 295+ HP PG
1964 Greenbrier Deluxe, 6 dr, 80 hp car engine, PG
2015 Chevrolet Malibu 2LT
2018 Chevrolet Silverado LTZ Z71 Centennial Edition
1947 Farmall A tractor 15 hp


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Re: 65 Monza Head removal
Posted by: corventure Dave ()
Date: October 10, 2018 02:26PM

To get clearance to do the thread repair I recommend removing the cylinder, rod and piston assembly near the pulled stud. Your going to have to go with a larger thread insert that won't go into the cylinder bore of the crankcase.
That you will have to evaluate.

Unfortunately I have had to replace the crankcase a couple times over the years when a stud repair failed more than once. Not a quick and easy thing to do, but it resolved the problem.

Corventure Dave

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Re: 65 Monza Head removal
Posted by: MattNall ()
Date: October 10, 2018 02:32PM

Surely it's the lower Rocker arm stud NUT 13/16"

That may be able to be repaired without pulling the head!

Right angle drill!





MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: 65 Monza Head removal
Posted by: Lane66m ()
Date: October 10, 2018 02:36PM

If you are close to Ken Hand (VairMech) in Michigan, he has tools that allow the repair without pulling cylinders, if I recall correctly. I suggest you talk to him and send him some photos to see what he also recommends.

Al Lane
Ellabell GA

1966 Monza Coupe, 110 hp, 4 Spd
1968 Camaro SS Coupe 350 CI 295+ HP PG
1964 Greenbrier Deluxe, 6 dr, 80 hp car engine, PG
2015 Chevrolet Malibu 2LT
2018 Chevrolet Silverado LTZ Z71 Centennial Edition
1947 Farmall A tractor 15 hp


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Re: 65 Monza Head removal
Posted by: Tony Trans Am ()
Date: October 10, 2018 02:37PM

Do I need to loosen rear engine mounts as I’ve read on earlier cars?

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Re: 65 Monza Head removal
Posted by: MattNall ()
Date: October 10, 2018 02:38PM

you need to LOWER the rear of the engine 4-6" to pull the head easily...





MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: 65 Monza Head removal
Posted by: Vin ()
Date: October 10, 2018 06:12PM

You can remove a head by just lowering the rear of the engine enough. I did it to put new rings on one piston and the recrosshatch that pistons cylinder. You will need to get some type of engine support underneath. I used a heavy duty motorcycle platform Jack with built in stops to hold the weight so I was not just relying on the hydraulics. Yes you remove the rear air grate to undo the rear engine mount. But you also need to then loosen the front mounting bolts (I believe there are 2 and they are hard to see and go into a cross member in the underside middle of the car). You will also have to remove all the sheet metal tin on top and bottom first so you can see the ground through the engine bay on that side. Also disconnect the fuel line and any electrical connections that would hinder the lowering process. Push rods and push rod tubes come out (put holes in a box to mimic the layout and keep the tubes and rockers and balls etc all in the same place so the pieces individually go back where they were). Final general note is that you will need to remove the carburetor on that side and will likely need to remove the tallest stud that holds that carb in place. I could not get the clearance to pull the head out without pulling that long carb stud. And my stud was stuck and it took a lot of grace to get it out and while I did not ruin the hole or threads I did have to buy a replacement stud. Measure the height it sticks out before you pull it. And when you put it back together don't forget to put the air baffles back on around the cylinders before you button it back up. If you have not done much work like this it may sound daunting but take it easy and one step at a time and while it might take awhile it isn't bad.


Vin
Dayton, OH
1965 Corvair Monza Convertible (4 speed)

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Re: 65 Monza Head removal
Posted by: American Mel ()
Date: October 10, 2018 06:20PM

Vin Wrote:
-------------------------------------------------------
. . . . . . . If you have not done much work like this it
> may sound daunting but take it easy and one step
> at a time and while it might take awhile it isn't
> bad.


THIS is very true!
I just did mine.
A first for me, and it took me a few weeks to do, between many other things.
I did NOT lower my engine, but I did remove BOTH SETS of Carb Studs, and the tin on that side of the engine.
In hind sight, it might have made things a little easier, but would have been more work also.

.
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
WA. state, 1 mile south of the Canadian border,
I am not at the end of the world, but you can see it from here.
'66 Monza Coupe - 4spd, 140 Daily driver beater
'67 Monza Vert. - PG, 140 Daily driver beater
'67 A/C Moredoor Monza - 140 4-spd. driver

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Re: 65 Monza Head removal
Posted by: Frank DuVal ()
Date: October 10, 2018 08:17PM

Warning:

If it is a manual transmission, be sure to disconnect the shift coupler! A#1 reason for bending the shift rod.

I have never loosened the front engine mounts (transmission crossmember nuts), but it certainly does not hurt to loosen them. Do tighten them and replace all cotter pins when finished.

Yes, do not forget the cylinder baffles. One of the first notes I wrote in a shop manual I use for engine assembly! angry smiley After I had to install them after assembly....

Frank DuVal

Fredericksburg, VA

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Re: 65 Monza Head removal
Posted by: martyscarr ()
Date: October 12, 2018 06:46PM

Hello Tony Trans Am: Are you still in the UK? I'm sure there are engineering suppliers there who would have oversize thread inserts, but if it is indeed a stud at the block you might have trouble finding a repair insert of the correct length.

Timesert makes an oversize thread repair insert called the Big-Sert and it's available from Amazon UK but it's about 150 GBP. It does come in different lengths, and is available in a 1.00 inch insert, but that doesn't come in the standard kit.

Helicoil also makes an oversize thread repair insert called the Twinsert but I can't tell if it's available in an appropriate length.

There is another solution, that is to make your own insert for this repair. Get an appropriate sized bolt, drill and tap it for 3/8-16 threads, and cut it to a length of approximately 1 inch. This will be much easier to do if you know someone with a lathe. Cut a slot in the end so you can screw it into the block after you tap the block for your newly made insert. The bolt will likely be a 1/2-13 bolt or 9/16-12 bolt, or you might have to use a metric bolt. Use thread locker on your new threaded insert to secure it in the block.

I just had to do this repair, I'll dig out some pics and post them.

HTH

Marty Scarr

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Re: 65 Monza Head removal
Posted by: martyscarr ()
Date: October 12, 2018 07:42PM

Here's the pics from the custom insert I made. First 2 pics are the stud with insert, the stud had already had a timesert thread insert installed. Last pic is cutoff bolt (9/16-12) being tapped for 3/8-16 threads.

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Re: 65 Monza Head removal
Posted by: martyscarr ()
Date: October 12, 2018 07:45PM

Pics of completed insert, I decided to install the stud into the insert and then into the block. Last pic is of block being threaded. Foil is to keep chips out of block.

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Re: 65 Monza Head removal
Posted by: martyscarr ()
Date: October 12, 2018 07:53PM

Pic of block after threading 9/16-12, then pic of custom insert driver so I could screw in the insert with the stud already in place. Last is completed job.

This repair was much less in cost than purchasing a Big-Sert kit. I have several of the Timesert products, just decided I wanted to get the car running and not wait for a kit. Worst part of the process is drilling and tapping the block.

This type of repair is detailed in the first edition of CORSA Tech Tips, IIRC. I think it was written by Larry Claypool.

HTH
Marty Scarr

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Re: 65 Monza Head removal
Posted by: joelsplace ()
Date: October 12, 2018 09:01PM

I'm surprised a Time-sert came out. Do you think it was installed incorrectly? Was it the correct length?

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Re: 65 Monza Head removal
Posted by: martyscarr ()
Date: October 12, 2018 09:49PM

joelsplace Wrote:
-------------------------------------------------------
> I'm surprised a Time-sert came out. Do you think
> it was installed incorrectly? Was it the correct
> length?

It surprised me as well. For some reason my old torque wrench didn't "click" at 30 pounds and I WAY over torqued it angry smiley

Length of the insert can be seen in pic 2 above, that's the insert with aluminum in its threads. I'm pretty sure it was a .900" long insert.



Edited 1 time(s). Last edit at 10/12/2018 09:50PM by martyscarr.

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Re: 65 Monza Head removal
Posted by: joelsplace ()
Date: October 12, 2018 10:07PM

I guess if the torque was high enough it's understandable.

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