Chevy C/ED 10134363 18deg SBC Heads

[maxracesoftware]

Chevy C/ED 10134363 18deg SBC Heads

originally Ported by Jimmy Bell for C/ED Class
2.180/1.600 Valves 45deg VJ on both Int and Exh sides
Angle Milled -2 degrees to 16 degree angle from 18deg

i will Post Flow Sheets + Pics later

however, first-off, my Customer gave me this Head to experiment with ,
they severly cracked this 1 Head when they bolted/torqued it on the Block !

#2 end-Cylinder is severly cracked on the :
outside
in the Intake Bowl
and across the Deck surface

the cracking problem was because no one
milled the Dowel-Pin hole deep enough on the #2 Cylinder end side
that Dowel-Pin hole = 0.156" deep

the opposite end Cylinder #8's Dowel-Pin hole = 0.183"
just enough not to cause cracking in that area

So who's responsible for this horrible messup ??
the Engine Builder or the Head Porter ??

i'd say both were !!!

as a HeadPorter + an Engine Builder :

as an Engine Builder :
one of the first things i check is the Dowel-Pin Hole depths
and also the Dowel-Pin height in the Block
and i always initially checkout Valve-to-Piston clearances + Dome clearances
"without" a Headgasket ( which is usually 0.040"nto 0.050" thick )
... so that if the Cyl Head goes down all the way on the Block surface + Dowel-Pins
i know when the Headgasket is in place there's going to be an extra +0.040 more clearance !

as a Head Porter :
i always mill those Dowel-Pin holes deeper in the Heads
to prevent the potential cracking problem as described above !
and to helpout the Engine Builder


In aluminum SBC Heads , i just drill the Dowel-Pin hole deep enough to break thru
into the waterjacket , then upon assembly use a little Dow Corning Clear silicone
on RightStuff silicone around the Dowel-Pin hole .

on older cast-iron SBC Heads , i carefully mill Dowel-Pin hole deep
as usually theres always an internal waterjacket iron curve or casting
to one side or half the Dowel=Pin hole's diameter
stopping you from milling the hole deep all the way thru to the waterjacket ,
otherwise , if you do attempt this with a Hand Drill you will just about
always break the Drill Bit ! .... you can do it in a Vertical Mill w/End Mill
with patience ! , then upon assembly use a little Dow Corning Clear silicone
on RightStuff silicone around the Dowel-Pin hole .

Cyl2cracks_1_1024x768.jpg

Cyl2cracks_outside_1024x768.jpg

Cyl8_no_cracks1024x768.jpg

[maxracesoftware]

Chevy C/ED 10134363 18deg SBC Heads
as received from Customer and as Ported by Jimmy Bell
Cylinder #6 was the best Flowing Int and Exh Ports
and Cylinder #4 was the worst Int and Exh Ports ... flow testing about 10 CFM less

Head is Angle-Mill to 16deg with 45deg VJ and 2.180/1.600 Combo on 4.125 Bore Flow Fixture
No Exhaust Flow Pipe

Meaux_10134363_Chevy_18deg_SBC_Cyl6_July_27_2021.jpg

i went to 50 degree Seat Angles on both Int and Exh sides
and re-Ported Heads , maxed-out Intake Ports,
but without breaking-thru at Headbolt holes nor any Headbolt hole Tubes either
real safe maxed-out Port .... they Flowed 393 CFM @ 1.100" Valve Lift like that ,
possibly would Flow test at +400 CFM @ 1.100" if they were completely maxed-out
with Headbolt hole break thru and/or Tubes in Place ,
and especially switching over to a 2.200" Int Valve from the 2.180" valve
plus possible 55deg seat angle too .

Meaux_10134363_Chevy_18deg_SBC_Cyl6_test4_Aug_3_2021.jpg

VerticalMillVJ1024x768.jpg

18degHead_newVJ_and_Porting.jpg

[rustbucket79]

If the head doesn’t seat with hand force or light rubber mallet any person with a brain would stop.

[Adger Smith]

Larry,
I have a set of Lump 19 Deg rolled and Cracked the same way. Someone fixed them.
I have always thought they froze and were fixed until I read this post.
Good to see you back in the shop working the magic.

[maxracesoftware]

Larry,
I have a set of Lump 19 Deg rolled and Cracked the same way. Someone fixed them.
I have always thought they froze and were fixed until I read this post.
Good to see you back in the shop working the magic.

Someone fixed them.

i'm happy to hear they were able to fix them !

the Head i have , not going to fix it , i just want to test out things on the Flowbench with it
i've since really maxed out Cylinders #2 and #4 , windowed Headbolt tube areas ( like Speier ) + widened CSA + Short Turn and Bowl work
and going to bandsaw the #2-#4 section off that Head to see thickness in areas , make more accurate aluminum templates , etc

i have a old pair of #10134363 18deg "brand new out-the-box" ,
all i did was install Ductile-Iron Seats , no Valve Job , + 11/32 Phosphor/Bronze Guides
they have thick unmilled aluminum Header adapter plates that go with the Heads
... i might Port them + max them out and sell them ?
or just sell them as is ??

i'll post some pics

[maxracesoftware]

10134363Chevy18degSBC1.jpg

10134363Chevy18degSBC2.jpg

10134363Chevy18degSBC3.jpg

10134363Chevy18degSBC4.jpg

10134363Chevy18degSBC5.jpg

10134363Chevy18degSBC6.jpg

[maxracesoftware]

those new 18deg Heads been sitting for very long time in my Shop
gathering grit, dust, and a few little Spider webs

in this Pic , those are Universal 3.000" long 11/32 KLine 0.502" OD steel guide with pre-installed Phosphor/Bronze alloy Liners
i "Knurled" only the OD on the top portion of those Guides to "set" the installed height above the Spring Seats
i will mill the tops of Guides down for seals and for final heights

these are super great Guides ... you can take a large Hammer and beat these flat as a Pancake
yet they will not split or crack

these Guides helped solve some problems NHRA Comp Elim Customers were having with
Chevy Canted Valve V6 and V8 Heads on the Exhaust sides !!!
i previously tried many other different exh Bronze guides , and all would waddle out or waddle-out + crack or split on the exhaust sides
switching over to these KLine guides completely solved all that ,
not one single failure , Valve-to-Guide clearance remained as brand new as the Day they were installed + honed to fit !!!

all the Ductile-iron Seats insert were installed with 0.008" press fit