Couple of post rebuild questions/issues

[mm289]

Hiya,

have finished the rebuild on my 1600TP and it is running "ok" but not feeling great, so got a couple of questions.

Just as a reminder this is a "get me by" engine just to get the buggy on the road for the summer, so isn't meant to be perfect.

Rebuild included full strip down, cleaned, measured and then rebuilt with new crank bearings, new cam bearings, new B&P and new lifters.

Engine is running a Solex 34 and 009 dizzy, starts and runs ok, changed the jetting to get a decent colour on the plugs and is timed to 32deg at full advance.

So questions:
1. Getting a lot of clatter from the what sounds like the valve train. Checked the gaps couple of times, had a fair bit of side play in the rockers so swapped out for a different set but made no difference really. I know I used new lifters on an old cam but the cam was in pretty good shape. Any suggestions on what might be causing the clatter - I can live with it but it is noticeable!

2. Ref the above, I know the piston pins were a little sloppy in the bearings - would this play sound like valve clatter?

3. What would you expect a fresh 1600TP to rev like? This one pulls 4500 in 1st & 2nd and tops out at 4000 in top. It is running big buggy wheels so I expect it is struggling to pull top gear, but it just feels kinda laboured. The 009 will be going soon as it has the typical flat spot on first acceleration if the revs are low, but I expected the engine to be a bit more free revving.....

4. When the timing is at 32 deg it runs ok, but will run a lot smoother with another 10 -20 deg advance, both at tickover and under load. Not running it at that as I don't want to melt the pistons! but is ths normal?

Any thoughts (built a few V8's and Wasser's before but this is my first aircooled )

And finally, a picture of the buggy on its first outing



Cheers,

MM

[helowrench]

Ok, the whole TP threw me for a bit, then I noticed your location. Twin Port, right?

Regardless......
Yes, the TP or DP engine will top out at 4500ish with normal size tires on it, depending upon the exhaust with the 34 Soles installed.
I would imagine that the tall tires explains the inability to rev past 4000 in 4th when you hit 4500 in 1/2/3

I will let the others speak to the clatter issue, other than this. You can tighten up your valves slightly, say .005" to see if it changes. If it does not, that eliminates the rocker/piston interface, but still leaves the rocker sideplay (shim kits can be used to tighten things up a bit, but solid shafts+ shims is the recommended option) and the wristpin interface.

Lastly. These engines in stock form have a redline of 4500. With all stock components, you really do not want to exceed that as it WILL allow a non counterweighted crank (stock) flex and pound out the case rendering it unusable, and good for only a very exciting bonfire.

Now, these engines can easily be built for 5k/6k/7k redlines, it just requires a careful selection of parts.
Stock crank limits to 4500-5000
Stock valve springs and rockers limit to 5500-6000

[Marc]

Wristpin noises tend to be a "double-knock". Loosen the plugwires at the cap so you can easily pull one out at a time with the engine running; if the noise diminishes when a cylinder is "killed" it's piston-related, if there's no change in the noise it's almost certain to be in the valvetrain.
Used rocker arms develop a "bump" on the side where they oscillate alongside the slot in `65-up rocker stands - if the geometry is changed that bump will bang into the stand in operation for some time before enough metal wears away to reestablish clearance. You can disassemble the rockers and knock the bump down by sanding the side of the rocker on a pane of glass (wet-or-dry sandpaper flooded with solvent works well).
A crude but effective way of isolating valvetrain noises is to jack one side of the car up, remove the valvecover, and grasp each rockerarm in turn with the engine running - you can almost always "feel" where the sound is coming from. This can be pretty messy if you do it for long so spread out some cardboard/newspaper if over a floor you want to keep clean; wear eye protection and clothing you don't care about

It's normal for an engine to sound happier with more spark advance (at least under light load) and therein lies the danger of "road-timing" or setting timing for peak dynomometer readings. The reason that one shouldn't exceed 32° total with the 0 231 178 009 is that it's advance is "all in" by ~2500 RPM and 30-32° is about all that is safe under full load at that speed. ~42° is OK at higher RPM, say 4500, if the load isn't excessive. It takes a more sophisticated distributor to pull this off; the 0 231 170 034 "SVDA" does it effectively by using a slower centrifugal curve that doesn't peak until >3500 RPM and an independent mechanism operating by ported vacuum from the carburetor which can add another 8-12° of advance when the load allows it.
Short answer: so long as you have the 009, don't exceed 32° total; that's already at the high end for a full-bodied car but should be fine for your buggy. If you possess superhuman self-control and will never mash the throttle fully until you're on the highway at 3500+ RPM you could get away with more, but I strongly recommend against it. DO check that your timing marks are accurate, and you may want to try someone else's timing light (preferably a NON-dial type) to rule out any error yours might have.

[mm289]

Awesome info, thanks guys, a few things for me to check this week.

cheers,

MM