rev.ronnie
Well-Known Member
Thanks, I love projects like these. It's like being a part of history
I'll have more pics later today, just finished line honing the block and I'm working on the rods.
1968 Street Hemi build
- Thread starter rev.ronnie
- Start date
Thanks, I love projects like these. It's like being a part of history
I'll have more pics later today, just finished line honing the block and I'm working on the rods.
Checking the stem for runout before truing the face. I have an Accu-Chuck on my machine, and it is accurate to .0001" or less, so this step will tell me if there is a particle in the collet, or if the stem is bent. Many ball type checks may require two or three attempts at getting zero runout. There should be a dial indicator on the valve grinder in any precision shop.
View attachment !cid_0828120106.jpg
View attachment !cid_0828120106.jpg
Grinding the seat angle true. Note that the indicator is now on the valve face. Valves come new in the box with runout. It's mass production. These Hemi valves needed the exhaust faces widened. They were only .050" on a street engine, I will run the seats .065" wide, so i cut the valve face to .080" . This machine will also true the face-to-tip length. It makes spring set up easier when they are all the same.
View attachment !cid_0828120108.jpg
View attachment !cid_0828120108.jpg
The valve grinder is a 2075 Sioux. It has a variable speed, Accu chuck and provides excellent finish. I have had many Sioux grinders over the years, they are my personal favorite.
When it comes to grinders, don't get worried if you see that your builder has an older machine. Maintained by a caring, conscientious operator, with the right tooling and coolant, they will grind a valve as good as the newest machine on the market.
View attachment !cid_0828120108a.jpg
When it comes to grinders, don't get worried if you see that your builder has an older machine. Maintained by a caring, conscientious operator, with the right tooling and coolant, they will grind a valve as good as the newest machine on the market.
View attachment !cid_0828120108a.jpg
Here I'm cutting the perpendicular face of the main cap parting surface. This is the reference I will machine off of to remove material from the cap's parting surface.
This step is important. If the caps are not indexed true and square, when the parting surface is cut, it will be crooked. This leads to big problems for the thrust bearing alignment. It also causes the bolt to flex because the seat is now crooked too.
View attachment !cid_0828120145.jpg
This step is important. If the caps are not indexed true and square, when the parting surface is cut, it will be crooked. This leads to big problems for the thrust bearing alignment. It also causes the bolt to flex because the seat is now crooked too.
View attachment !cid_0828120145.jpg
This is what the side should look like when it is machined perpendicular to the parting face. Now we have a surface to reference from.
View attachment !cid_0828120148.jpg
View attachment !cid_0828120148.jpg
Grinding the parting face for line honing. This machine will bring the same amount on each pass once the stone is set. Each cap will get 3 passes at .001".
View attachment !cid_0828120152.jpg
View attachment !cid_0828120152.jpg
Checking size as we go. I think my camera lens has honing oil on it!
View attachment !cid_0828120233.jpg
View attachment !cid_0828120233.jpg
Main bores are finished. I will re-check again when they have cooled. The next step is to bolt the bearings in place and mic up the bores. I will deduct the clearance and supply this spec to the crankshaft grinding man. The same with the rods. This is way better that playing musical bearings.
The crank in this engine had .001" under mains already. They were inconsistent as well. They will go .010" under for sure. The rods may stay at standard. I will know when I finish the housing bores. That is next.
View attachment !cid_0828120233a.jpg
The crank in this engine had .001" under mains already. They were inconsistent as well. They will go .010" under for sure. The rods may stay at standard. I will know when I finish the housing bores. That is next.
View attachment !cid_0828120233a.jpg
Meep-Meep
дворянин
Very nice documentation. Thanks for posting.
The original caps on my 68 hemi block were ridiculously loose in the registers so I got new Pro Gram caps and will be fitting them with .002" interference. The trick will be fitting the three cross bolt caps. What I don't want to do is have the cross bolt registers influence the cap placement so I will set those a little looser, like a slip fit or up to .001" gap on each side. Your thoughts?
The original caps on my 68 hemi block were ridiculously loose in the registers so I got new Pro Gram caps and will be fitting them with .002" interference. The trick will be fitting the three cross bolt caps. What I don't want to do is have the cross bolt registers influence the cap placement so I will set those a little looser, like a slip fit or up to .001" gap on each side. Your thoughts?
rev.ronnie
Well-Known Member
I know that with the retro fitted cross bolt caps on the wedge big blocks, there is interference between the side registers and the cap, on both points of each side. It helps them with repeat-ability as far a size after machining. Program gives you a blueprint sheet that you machine off of. It is probably .002"-.003" on the main register and .0015"-.0025 on the pan register. You find your reference (the cap side register) on the squared up block in the milling machine and use the DRO from there. If it's done correctly, the two registers will be where they want them to be. (where Program wants them).
Oh, one other thing, make sure as heck to lube the registers with moly each time you install them. The steel cap will gall up and it will go out of round after a few dry installs otherwise. Take care not to get any moly on the parting surface...that will affect the size too. Remove and install a couple times to ensure consistency.
The Program caps have a pre finished thrust. Make sure to sweep it in with the line boring bar and a travel stop to make sure it's face is true with the block. This way, if you have to adjust it (shim and grind the parting face) you do it before the bore is finished. Sometimes you have to ream the holes a little to get it to move fore and aft to where it needs to be as well.
Hemirunner
Well-Known Member
Sure it can. I run a 572 hemi on the street and it runs and drives better than most big blocks that I see around and probably gets better mileage too.
Rev,
What ring package are you putting back in this? Surely not the 5/64 stuff. I've been running .043/.043 napier/3mm oil even in the big bore street stuff.
Rev,
What ring package are you putting back in this? Surely not the 5/64 stuff. I've been running .043/.043 napier/3mm oil even in the big bore street stuff.
court9155
Well-Known Member
To touch on this, upon disassembly, how did you identify that valve guide contamination was the cause of the valve stem damage versus say an oiling issue? I am not nit picking, I genuinely would like to know because I have a set of AFR heads for a SBF that have wrecked valve stems after only 25 minutes of run time.
Dan
rev.ronnie
Well-Known Member
Unfortunately, I am stuck with the 5/64 crappy ring pkg. For some unknown to man reason, KB makes their hyperutectic piston with this crappy ring Pkg. this car is probably never going to see any sort of hard driving again in its life with the original/current owner, so I don't think she will miss the 20 HP....
Total Seal makes a spacer set to use 1/16" rings, and I would consider that if it it was going to get run hard. They even has a top ring spacer with a lateral gas port groove. Great for NHRA Stock eliminator.
I love the .043" .043 3mm ring pkg. I have been using that as well. I even use the Advanced Profiling Total Seal .028" TiN rings in some Superstock engines.....beautiful.
rev.ronnie
Well-Known Member
Like Hemirunner says. YES! Most pistons today require less clearance then OE, and with hyd. Roller cams and mild compression, they run beautifully.
rev.ronnie
Well-Known Member
Dan,
If there was contamination, you will see, particularly on the intake valve stems, scoring lines running the length of the valve in its travel. You may feel them with your fingernail.
If it is an oiling problem, the stems will be blackened and you will see signs of heat. The guide may even be tight on the port end.
If the timing is not set correctly, say it is retarded, and someone were to try to break in the cam. The exhaust valve stems can gall too. We break everything in on the dyno, so you will see that the temps are inordinately high. Doing it in the car, well, it's a coin toss.
The timing is better off advanced than retarded in the first minutes of the engines life. There is no load anyway and the exhaust valves run cooler.
Meep-Meep
дворянин
OK, my thought process was good just the numbers a bit off. Thanks for the tip about the thrust. I haven't got there yet but I'll be sure and check it when I do.
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