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Glenn Mr. 010
Joined: December 25, 2001 Posts: 76760 Location: Sneaking up behind you
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Posted: Tue May 24, 2022 8:25 am Post subject: Re: Changing 40hp round boss to square boss |
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Dan Ruddock wrote: |
or swap out the rocker block for late ones. |
So just replaced the rocker shaft block with ones from a 1600??? I have a few sets laying around. _________________ Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
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Brian_e Samba Member
Joined: July 28, 2009 Posts: 3228 Location: Rapid City, SD
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Posted: Tue May 24, 2022 8:54 am Post subject: Re: Changing 40hp round boss to square boss |
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Correct. I have done few square boss 40hp engines with 1600 rocker arms, shafts and blocks. Easy swap, and the tiny bit of extra lift can't hurt anything.
These heads also respond really well to blended intake bowls, a back cut intake valve, and a good valve job. Don't touch the exhaust port. It already flows to much. Just the seat cut on the exhaust.
Brian _________________ www.type-emotorsports.com |
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EVfun Samba Member
Joined: April 01, 2012 Posts: 5446 Location: Seattle
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Posted: Tue May 24, 2022 10:43 am Post subject: Re: Changing 40hp round boss to square boss |
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Glenn wrote: |
So new heads, 8 top studs and drill the rocker pedestals for the larger rocker studs is all that needs to be done. |
My understanding is that the pushrods need to be changed too. The late 40HP square boss heads used pushrods that where 2mm longer. VW knurled one end to mark them. _________________
Wildthings wrote: |
As a general rule, cheap parts are the most expensive parts you can buy. |
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Glenn Mr. 010
Joined: December 25, 2001 Posts: 76760 Location: Sneaking up behind you
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Posted: Tue May 24, 2022 12:15 pm Post subject: Re: Changing 40hp round boss to square boss |
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EVfun wrote: |
Glenn wrote: |
So new heads, 8 top studs and drill the rocker pedestals for the larger rocker studs is all that needs to be done. |
My understanding is that the pushrods need to be changed too. The late 40HP square boss heads used pushrods that where 2mm longer. VW knurled one end to mark them. |
2mm sounds minimal _________________ Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
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heimlich VWNOS.com
Joined: November 20, 2016 Posts: 6558 Location: Houston, Texas
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Posted: Tue May 24, 2022 12:34 pm Post subject: Re: Changing 40hp round boss to square boss |
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There are some kits that do what you are asking for the round boss heads. But you broke the boss - hoss.
I may have some of the stud kits if that would help you.
Hopefully this thread tells you what you need:
https://www.thesamba.com/vw/forum/viewtopic.php?t=587766&start=0 _________________ www.vwnos.com [email protected]
Classic Brands. Classic Quality.
Not all parts are made the same. NOS OE/OEM parts made mainly in West Germany, Early Germany, and Early Brazil are where VW produced the best quality parts and best fitting products.
5% Off your order with coupon code: 5%OFF
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Glenn Mr. 010
Joined: December 25, 2001 Posts: 76760 Location: Sneaking up behind you
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Posted: Tue May 24, 2022 12:56 pm Post subject: Re: Changing 40hp round boss to square boss |
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This engine already had the repair kit installed. It was the steel repair insert that ripped out and broke the boss.
Engine is apart, just need to finish the research and order parts.
Gonna check if the shop has 40hp pushrod tubes. If not i'll be in touch.
BTW, do you have 40hp flywheel shims?
_________________ Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
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heimlich VWNOS.com
Joined: November 20, 2016 Posts: 6558 Location: Houston, Texas
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Posted: Tue May 24, 2022 1:40 pm Post subject: Re: Changing 40hp round boss to square boss |
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40HP flywheel shims were all but gone years ago. A customer told me that Wolfsburg West started making some recently.
I've got a couple 40HP heads laying on the floor under a workbench. They were used and came with a pile of new heads. I'll probably never do anything with them if they'd be of help.
I've got pushrod tubes. They are nice ones too from Brazil. When I say nice I compare to what's made now for 1600. Those are really thin metal. These are a bit thicker and are covered in sticky oil. _________________ www.vwnos.com [email protected]
Classic Brands. Classic Quality.
Not all parts are made the same. NOS OE/OEM parts made mainly in West Germany, Early Germany, and Early Brazil are where VW produced the best quality parts and best fitting products.
5% Off your order with coupon code: 5%OFF
Restored Distributors Available (<--Click here) |
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fl59bug Samba Member
Joined: November 23, 2005 Posts: 1976 Location: North Carolina
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Posted: Tue May 24, 2022 2:18 pm Post subject: Re: Changing 40hp round boss to square boss |
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....
Last edited by fl59bug on Wed May 25, 2022 12:01 pm; edited 1 time in total |
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Glenn Mr. 010
Joined: December 25, 2001 Posts: 76760 Location: Sneaking up behind you
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Posted: Tue May 24, 2022 7:22 pm Post subject: Re: Changing 40hp round boss to square boss |
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OK... next question:
Who sells new/rebuilt 1200cc 40hp square boss heads?
I've checked the usual vendors and 99% don't even have a listing. I did find a handful but all say they are out of stock. _________________ Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
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modok Samba Member
Joined: October 30, 2009 Posts: 26743 Location: Colorado Springs
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Posted: Tue May 24, 2022 7:58 pm Post subject: Re: Changing 40hp round boss to square boss |
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I probably have some of the shims. |
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heimlich VWNOS.com
Joined: November 20, 2016 Posts: 6558 Location: Houston, Texas
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Posted: Tue May 24, 2022 7:59 pm Post subject: Re: Changing 40hp round boss to square boss |
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Square boss is hoss. The racers usually take them all.
You can pick them up in singles. You'll need the correct size crush washer when you install them. There are two sizes 32MM and 34MM. _________________ www.vwnos.com [email protected]
Classic Brands. Classic Quality.
Not all parts are made the same. NOS OE/OEM parts made mainly in West Germany, Early Germany, and Early Brazil are where VW produced the best quality parts and best fitting products.
5% Off your order with coupon code: 5%OFF
Restored Distributors Available (<--Click here) |
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Glenn Mr. 010
Joined: December 25, 2001 Posts: 76760 Location: Sneaking up behind you
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Posted: Wed May 25, 2022 5:14 am Post subject: Re: Changing 40hp round boss to square boss |
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modok wrote: |
I probably have some of the shims. |
The engine has no "feelable" endplay. I'll get around to using a dial indicator to measure. If needed I can have the snout of the flywheel machined to what's needed.
Or I can just leave it alone since that's how it came in... i'll let the customer decide. _________________ Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
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esde Samba Member
Joined: October 20, 2007 Posts: 5927 Location: central rust belt
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Posted: Wed May 25, 2022 5:38 am Post subject: Re: Changing 40hp round boss to square boss |
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Glenn, I have a pair of nice round boss 40hp heads. Looks like they were rebuild many years before I got them, but they've been sitting and would need to be at least gone over. Pm me if you're interested. They came from a closed shops inventory _________________ modok wrote:
Bent cranks are silent but gather no moss. I mean, ah, something like that. |
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Chickensoup Samba Member
Joined: January 06, 2018 Posts: 5368 Location: Good Hope, GA
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Posted: Thu May 26, 2022 6:33 pm Post subject: Re: Changing 40hp round boss to square boss |
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first off, if you decide to run square boss 1200 or 1300 heads, you need to use "1600" style push rod tubes.(i think)
the square boss 1200 heads are physically taller.
I can snap an early 40hp push rod with my pinkie toes. a 1600, not so much.
just buy 1300 heads or make it easy and find some good round boss cores. heimlich has some NOS 1200 and 1300 heads.
also, i bought my 40hp tubes from Heimlich. he may still have some. _________________ -'85 c10 5.3 LS, 222 cam, long tubes, x pipe, 3 inch spin tech's
-'05 B5.5 TDI Wagon 17in sport rims ;EGR + BSM + ASV Delete, Stage-2 Tune, straight pipe
'65 Tourist Delivery Build
'66 RIP
'69 RIP
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Glenn Mr. 010
Joined: December 25, 2001 Posts: 76760 Location: Sneaking up behind you
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Posted: Thu May 26, 2022 6:37 pm Post subject: Re: Changing 40hp round boss to square boss |
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Bought a good clean set of round boss heads from esde (Seth)... thanks.
Don't want to reinvent the wheel, just want to get this engine back together for a reasonable cost to the customer and send it down the road.
Plan is to have them gone through by our machine shop and reinstall. _________________ Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
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