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machined head-???
https://www.slantsix.org/forum/viewtopic.php?t=60029		 Page 1 of 1
Author:  Badvert65 [ Thu Aug 11, 2016 6:56 am ]
Post subject:  machined head-???
I picked up my second big valve slant head (first is still at the other shop-10 weeks and counting). There is something I didn't notice until I got it home. The side of the chamber has been machined for the bigger valves (unshrouded) which I did see. What I didn't see is that if you look at this picture, all of the cutting was to the right side of the chambers. That means, on the left side-cylinders 1-3 have the intake valve unshrouded. to the right, cylinders 4-6 have the exhaust valve unshrouded. That just seems a bit odd to me. I would have thought that the intake valves would require the cut on all cylinders as that is the biggest valve. I am going to run with it but it is a little unnerving.
Image
Author:  Joshie225 [ Thu Aug 11, 2016 7:28 am ]
Post subject: 
Abort, abort! Who knows what else they screwed up!
Author:  Badvert65 [ Thu Aug 11, 2016 7:47 am ]
Post subject: 
Everything else looks good. No guides off center or crooked. Valves aren't sunk, etc.
I haven't rechecked the chamber cc's. I asked that 080 be shaved from the head to get the chambers down to 45cc (from 57cc).
That shop has good reviews and (supposedly) know what they are doing.
They were well aware that the head was for racing.
It's always something....
Author:  Rick Covalt [ Thu Aug 11, 2016 8:55 am ]
Post subject: 
Did the new shop do this or was it factory cuts? Either way they probably did not realize that the valves are reversed from the front 3 to the back 3 cylinders. If the shop did them then they should unshroud the other intakes. I may have them make all of them the same as long as the head gasket sealing ring is not compromised.

Rick
Author:  Badvert65 [ Thu Aug 11, 2016 9:17 am ]
Post subject: 
It was the machine shop that did this. There were no cuts in the chamber previously. I hate taking it back if it is just something I can do myself.
ARGHHHH!!!
Author:  sandy in BC [ Thu Aug 11, 2016 9:22 am ]
Post subject: 
sorry buddy,,,,thats just wrong.

If I were that machine shop I would be embarrassed knowing you posted that on the inner net.

Send them a new head for a doo over.

No way those chambers cc right.

Amachers.
Author:  Badvert65 [ Thu Aug 11, 2016 10:58 am ]
Post subject: 
This is precisely why I prefer to do things myself.
Author:  sandy in BC [ Thu Aug 11, 2016 1:27 pm ]
Post subject: 
Long ago in a 64 Galaxie ...far far away...

My machinist friend and I radiussed the chambers on my big valve head.

We paid a modicum more attention than your machine shop .....it turned out well.

Make them redo.
Author:  Rick Covalt [ Thu Aug 11, 2016 1:35 pm ]
Post subject: 
I would have them cut them all the same and let them redo the planing to get the CR you want. Is unshrouding the exhaust going to hurt performance at all? If so then the previous statement is out.

Rick
Author:  slantzilla [ Thu Aug 11, 2016 3:55 pm ]
Post subject: 
Have them recut the other side so they are all equal, then mill to your desired CC.

As long as the relief isn't past the fire ring on the gasket you will never know the difference.

Then, find a new machine shop.
Author:  Badvert65 [ Thu Aug 11, 2016 5:20 pm ]
Post subject: 
As far as machine shops...
I guess I am 0 for 2.
sigh....
Author:  DusterIdiot [ Thu Aug 11, 2016 5:24 pm ]
Post subject:  Ouch...
Yeah, that's what you get when a V-8 guy does the head and doesn't look to see how the valves are positioned....

Typically, I would have the head hot tanked, and magnafluxed.... Have the seats checked and valve guides installed... Then I pick up the head, do my porting and valve reliefs (take a head gasket and scribe the inside fire ring on the gasket surface with a scratch awl...)... once done I drop it back off and have them do their valve job, and mill to finish...

Like others have said, check the position of the fire ring on your head gasket, and have them relieve the other side if they didn't put the edge into the ring on this attempt, then they will need to make a clean up pass....
Author:  Badvert65 [ Fri Aug 12, 2016 5:05 pm ]
Post subject: 
Head was magnafluxed and pressure checked, not certain if before or after machining. I measured the combustion chambers and they are all in the 44-46 cc range, basically only slight variances from 45 cc which is what I was aiming for. I used a head gasket and checked the edge of the cut out is right at the edge of the fire ring. It's weird though, the other side of the chamber (the uncut side) is also right on the edge of the fire ring. Is it possible that the head was cast off center?
Author:  terrylittlejohn [ Fri Aug 12, 2016 5:25 pm ]
Post subject: 
yes it can be off center , just bolt the head to the block with no pistons and have a look. on my 80 over engine with 1.80 intake/1.60ex valves I notched the block for clearance on exhaust side and there was a shift from combustion chamber to cylinder center.
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