For all the engine builders...

[Doug D.]

A few last questions for the engine builders here...

First I wanna say thanks to all the guys who jumped in with advice and pointers through the course of what has been a very trying and expensive year. And a special thanks to Rex, who has demonstrated saint like patience with my endless PM's while I fumbled through this whole process.

Ok. I bought an 1835 long block, built on an AS21 FI case, with a stock 1600 DP crank and rods, and an Engle W100 cam. The heads were from a 1600 DP, cut for the bigger jugs, with stock valves. I set it up with my 32/36 progressive carb, a 009 dizzy with points and a set of 1.25:1 HR rockers.

I didn't get a 1000 miles on the build and it cracked the head on the #1 cylinder, between the spark plug and intake valve. After some deliberation, screaming, cussing and tool throwing, I opted to get a new set of heads as opposed to rolling the dice on a set I had laying around. I picked these up yesterday. So $500 later, I'm ready to reassemble (again), but first a few questions for the experts so I don't build another rolling hand grenade.

1.) I'm putting this together to attain an 8.5:1 compression ration, or at least get close to that. What I have is a .055" average deck height with the heads cut to 50 cc's. I intend to keep running the 1.25:1 HR rockers over the aforementioned W100 cam. The question is, will this set up give me enough valve clearance to avoid a catastrophic collision between the valves and pistons, not to mention the subsequent screaming, cussing and tool throwing that would most assuredly ensue?

2.) Next question, is there a specific pattern one should follow when torqueing down the head nuts?

3.) Last, on a whim this evening, I measured the crank end play. This checked at .013". The question is, how much end play is too much?

Thanks again to the whole Trike Talk gang for your patience and understanding, and for making this a great place to visit!

PEACE and ride safe!

[Sidecarbill]

Cracks in the cylinder head in that area aren't uncommon. Most people don't know it till its taken apart. Just curious what the symtoms were to make you tear it down?

[Doug D.]

It developed a nasty miss on the 1-2 side. After peeling through everything else, I decided it was time to pull the head. Lo and behold, there it was.

[vwbug72501]

First of all, invest in a good service manual. Here's one that I like: https://www.amazon.com/Volkswagen-Se...ords=VW+manual This is the "Bentley Manual" that you will see referred to in many forums.

As for valve clearance, an old trick is to put some modeling clay on top of the piston, install the head, just snug it up, rotate the engine by hand through an entire intake/exhaust cycle, remove the head, and measure the thickness of the clay at the valve/piston contact area. With that clearance information you will be able to proceed go/no-go decisions or research.

There are 2 torque sequences:

Initial - 7 ft-lbs

Final - M10 nuts 22-23 ft-lbs and M8 nuts 18 ft-lbs

Remember, aluminum engine.

Manual says crank end play should be .003 to .005 in with a wear limit of .006 in.

Hope this helps.

[DeathBySnuSnu]

Correct and solid advice there.

And you typically do not run into valve to piston clearance issues until you get way up there in durations. Like and fk89.

Mine handily clears with an fk10.

The first cam lift related issue you run into is the valve retainer hitting the top of the valve guide.

The bronze guides can be installed with too much out the spring side or any number of things with quality control.

It is not unusual to shorten the guide.

8.5 is on the high side of acceptable with that cam.

I would say 8 to 8.5 is the optimal range.

I would much prefer a 8.5 and .055 deck above a 8.0 with .110 deck.

[stinger608]

I would agree; with the Engle 100 cam, you're not going to run into any valve to piston clearance issues.