Pistons in the YELLOW coupe are 3.625" diameter, which is the 220 international pistons, .060" over. they are fully machined on the dome to accept the combustion chamber of the buick. The wrist pin diameter is the same as buick. The rings for the international pistons are WAY too thick at around 5/32" if I remember correctly. I made aluminum inserts that went in the international ring lands, then re-machined the inserts to accept a .062" thickness compression ring, and 4mm oil ring. This GREATLY reduces the friction as well as I can buy rings at nearly any auto wherehouse.
Yes I run a SOLID copper head gasket with .025" quench pad from the piston to the head.
Crank is stock, rods are stock rods that have a T-1 plate bolted in the original gap, then a grade eight bolt bolted in the bolt hole of the small end of the rod, then torqued down and loctited. I then machine out the portion of the bolt that is left in the pin bore and bush the rod for a full floating pin. I will not weld on a rod, for metalurgy reasons.
The camshaft in the Yellow coupe is a LDB Isky Cam, track 2 grind. It works well to about 6k. The drag/bonniville car motor has a CRANE cam grind in it. It is a SBC grind out of all things. It is fairly radical, and tough on the street.
Lifters. I use SBC lifters in the yellow coupe, I bused the block with bronze bushings to use these lifters. In the Drag motor I use Mopar mushroom lifters, with a small sleeve pressed on the lifter to come out to the 1" diameter needed for the buick block. I made my own chromolly push rods, using stock ends. You can use GMC lifters after they are metal sprayed or hard chromed as they are .990" stock. My piston to valve clearence is .050" on the intake, and .090" on the Ex. The yellow coupe has stock valves in it, the drag motor has speacial .3125" diamter stems, forget what they come out of, as We have a master valve book, and we just go by dimensions and part numbers. On the Cad rockers, I belive V-12, but Ill have to check and verify that.
On porting, they are fully ported heads on both motors, and also brazed in alot of the spots. The intakes I bore straight down to enlarge on the mill, then hand grind from there. EX are brazed in the roofs as well as We grind them way to thin for a gasket to work between the head and the header. I belive we are at a 73% intake to ex comparison, I will have to dig up my flow bench numbers to verify that as well, as it has been awhile. We have experienced with using a divider in the port to get rid of the 4 port design, and it seems to work well, but we have not ran it on a can yet. We are also making a fully billet alluminum head, actually bought the chunk of 6061, as well as started the cad work on that as well, but we are still playing with CFD testing for port design.
What do you have against using standard Buick lifters? As far as I understand, the cam can be ground with faster ramps when using large diameter lifters?
Anyways, a humble thanks - this information is invaluable
All the folks on this forum, take note: Bryan is willing to go into detail to benefit this community. We are here to share information and experience, not just to private mail or to throw some general comments for bragging rights.
Bryan, it surprises me you're going to whittle a custom crank and head out of a billet blank, but you never made any roller rockers! I'm sure your shop could manufacture a set of hi-lift roller rockers pretty easily, or better yet, a short production run...
I wonder how difficult would it be to purchase a few bars of extruded aluminum blanks from one of the rocker mfg's out there?
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He's Tom Telesco, or telriv on this site...
36 Century...you are the man...I'm always jealous of the things good machinists can do...
1953 Special Riviera 45R
1965 Skylark Hardtop 300-4V
1965 Mustang (in the family since 1968)
1965 Corvair Monza Convertible
1965 Dodge Dart 170 Wagon
1974 Pontiac Firebird Esprit
You know what, I think I will tool up my CNC to build a set or two of rocker arms. I am thinking of about a 1.6-1 ratio. I can build them all out of billet, without a problem. How many of you guys might be interested. I will build a couple and post pics, to see what you guys think.
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