Thread: 355 build HP and Torque?

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Are you aware that there are adapters available to convert center-bolt heads so they can accept the older-type valve covers? If you want to make your engine look period correct, check them out. Here's a link:

Valve Cover Adapter for Center Bolt Heads - Speedway Motors, America's Oldest Speed Shop

Originally Posted by rumrumm

Are you aware that there are adapters available to convert center-bolt heads so they can accept the older-type valve covers? If you want to make your engine look period correct, check them out. Here's a link:

Valve Cover Adapter for Center Bolt Heads - Speedway Motors, America's Oldest Speed Shop

Thanks Lynn,
Yes I checked those out, but at this point my budget is wiped out by all the main engine part upgrades. I may eventually go that way, but am looking for a cheap solution to get me through this initial phase. I have also looked at the finned aluminum vortec style, with the Chevrolet script which only use the end two center bolt holes, which on casual look, appear fairly correct. I'm still using the original factory rockers, so the smaller covers should still fit. Like these:

on them GM retro covers are neat but how are you going to vent the engine and add oil the engine must breathe just like you. on the 906 and new GM heads the stock intake valves in many cases just will not clean up on a re grind if so the margin is very thin so it.s cheaper and smart to start out with new valves i do not spend much time cleaning valves when a new oem valve is less them 6.00 each you get a better job and no worrys of pull threw or cupping . the ex most of the time do have abit of margin and will take a clean up . if stems are not worn threw chrome on the valve stems

Update:

After cleaning my block, the machinest found a couple cracks in the lifter valley. He reccomended I find another block. Yesterday I picked up another engine off Craigslist. It is the same casting number as my original,14093638 and cast for the roller lifters, but the final machining is not done. I think I can handle drilling and tapping the spider risers and camshaft front retainer plate mounting.

I mocked up a dogbone and lifter and found there was quite a loose clearance where the lifter fits inside the dogbone. So much that even if the dogbone doesn't sit perfectly square with the lifter, it still slides up and down without resistance. At this point I'm thinking of just grinding a little off the backside bottom of each dogbone where the the block is filleted and it should sit and operate just fine.

If anyone has any personal experience with this, I would appreciate their feedback.

Here's a couple shots of the new block:



This new block is not drilled for the mechanical fuel pump either. I'm a little disappointed as my cracked block was almost perfect for what I wanted. I understand there is a jig out there that can be purchased for drilling for the the pushrod and drain hole, but it cost almost $1000. That's ok, I've run electric fuel pumps before and do not object to them at all.

Good news,

I got the vortec heads back from the shop, magnafluxing showed no detectable cracks. To minimize the possibility of having the rocker arm studs back out under hard use or higher valve lift, I decided to drill and pin the studs in place. Some people have suggested drilling, tapping and install new screw in studs, but the pinning idea seemed to be more economical and plenty good for my mild build. My intended cam will have only a .500" lift with typical roller lifter ramp speeds.

I picked up a pin kit from Mr Gasket that consisted of 16 roll pins and a drill bit for $13.


With the high sides on the vortec heads it is just about impossible to drill the risers at 90 degrees to the studs and locate the hole 9/16" down from the top per the instructions that came with the kit. By mounting the head in the mill at a slight angle, and positioning the drill bit tight up against the head railing, I was able to start the holes from one side about 3/8" down and to angle the hole so it came out the other side at about the 9/16" position.


The original bit that came with the kit lasted about 2-1/2 holes using good pressure and lots of oil before the tip ground down or chippped to the point and wouldn't drill any more.


I had bought a couple extra titanium coated ones just in case as I had heard from others, that I would need to either have extras or do a lot of resharpening. The first titanium bit worked just fine for the remaining 14 holes.


With the head still clamped in the mill, I tapped the roll pins in. The instructions say to position them so the end nearest the valve is flush, but I found the entire length of each pin was almost exactly the same as the riser width so they mostly ended up with both ends flush.



Here's a shot showing the side closer to the valve


With all the pins successfully in place, I spent some time running a tap and cleaning out all the threads in each head. Looks like my next job is to clean them up thoroughly and reassemble the valves, springs, and rockers. I understand I should probably look into purchasing all new locking retainer nuts for the rockers.

Originally Posted by rollie715

Update:

After cleaning my block, the machinest found a couple cracks in the lifter valley. He reccomended I find another block. Yesterday I picked up another engine off Craigslist. It is the same casting number as my original,14093638 and cast for the roller lifters, but the final machining is not done. I think I can handle drilling and tapping the spider risers and camshaft front retainer plate mounting.

I mocked up a dogbone and lifter and found there was quite a loose clearance where the lifter fits inside the dogbone. So much that even if the dogbone doesn't sit perfectly square with the lifter, it still slides up and down without resistance. At this point I'm thinking of just grinding a little off the backside bottom of each dogbone where the the block is filleted and it should sit and operate just fine.

If anyone has any personal experience with this, I would appreciate their feedback.

Here's a couple shots of the new block:



This new block is not drilled for the mechanical fuel pump either. I'm a little disappointed as my cracked block was almost perfect for what I wanted. I understand there is a jig out there that can be purchased for drilling for the the pushrod and drain hole, but it cost almost $1000. That's ok, I've run electric fuel pumps before and do not object to them at all.

Is it just the photos or what? It looks like the lifter bores have not been cut on the top of the boss for the dogbones to lay down flat. Compare your old block to the new one.

Originally Posted by techinspector1

Is it just the photos or what? It looks like the lifter bores have not been cut on the top of the boss for the dogbones to lay down flat. Compare your old block to the new one.

Richard, you are correct, they are not cut.
However, my plan if they are a usable height such that the dogbones sit low enough to encase the top portion of the lifter, is to modify the dogbones to sit flat by grinding a small bevel on the bottom rear edges. The existing block surfaces are already mostly flat and perpendicular to the lifter bores, except for a little radius on the back edge. Instead of machining out that radius as the factory did, I was planning to modify the dogbones a little. The slots in the dogbones already have plenty of extra room in them to not bind on the lifters even if they sat at a little angle, so I figured with a little bit of work, they should be just fine.

As usual, I am the novice here, so if I'm missing anything, please advise me. If I have to, I can have the surfaces machined, the same as the factory, but I'm hoping to spare that added expense if I can.
Rollie

Never tried it personally, but my best instincts tell me that the factory would not have spent one thin dime more than they had to in order to make the dogbones work. They spent additional money to cut the top of the guides for some specific reason. Of course, us hot rodders have been altering what the factories produce ever since there have been factories, so do whatever you think you can get away with.

EDIT-
Surfing for info and came across this....
http://www.jalopyjournal.com/forum/a.../t-478632.html