Tear Down and Reassemble Unstarted 1.7 built to 2270, 1.7 to 2270 Unstarted 10 Year Old Build Options

[Robroe]

Moved from topic of first start of 10 year old build to tear down, inspect and reassemble. The 10 year old build is from a 73 1.7 to a 2270. Stroked to 78 mm and 96 mm cylinder diameter. Heads are Ham/RAT with 36 mm exhaust and 44 mm intake. Both are nicely ported.

Have torn it down to the case and checking crank end play before I split the case and pull the cam and crank. So far, everything is new and looks in good order. I'm concerned about oil passages being blocked with old assembly lube so a complete tear down and reassemble is happening. Discovered stacked cylinder spacers (4) totaling .150". So looking to replace those with single spacers. So far I can only find .160" spacers from type 4 store and may just use them as impact on compression appears minimal. Was shocked to discover crank end play is .450"! Sure glad I didn't try to start this thing. Will check again in the morning to make sure I'm checking it correctly, but I'm doing the same thing on the videos such as Ian Carrs YouTube engine builds so pretty sure I'm checking it correctly. Now to figure out what to do about that huge end play.

Any thoughts about what to watch out for?

[technicalninja]

That pic is from the Jake's crankcase video.

914werke was pointing out that there are two holes in the oil tower (my name for that part of the casting, might be mis-named, I'm weird!).

We all have questions as to what it does and why two holes are needed.

The most obvious reason is for crankcase ventilation.

Jake can be secretive and didn't mention them.

A vent already exists in this area, and it seems redundant to many of us to add more.

Crankcase ventilation is CRITICAL for multiple reasons but one of them is oil leaks.

If a crankcase is completely sealed it will quickly gain internal pressure from blow by gasses (all engines have some) and heat. One path for this excessive pressure is through any seals/gaskets on the engine. They blow outward...

Modern engines are scavenged by the PCV system, and the "normal" method is to create a metered flow into the intake manifold.

The engine SUCKS itself! (IMG:style_emoticons/default/happy11.gif)

Dry sump engines have enough suction from the scavenge section of the pump that they can pull a vacuum to the point of gasket and seal failure as well.
In this scenario the seals/gaskets fail inward.
Hence my comment of vacuum release valves in a previous post.

So, the answer to your question is Yes, this has bearing on seal/gasket life, but it is not DIRECTLY for RMS improvements alone.

We would all like to see how Jake has those holes plumbed.
What are they hooked up too?
The really important question is why did he do it this way?
He always has reasons and the level of experience he has makes him "Top Dog" to many of us.

Knowing the WHY allows us to apply similar techniques to other builds.
Might not be German at all.
Most of us (the gear heads) are as interested in the "Journey" as the end result because we know this is NOT the only "Journey" we will travel...

I'm no longer planning on taking a T4 journey. I've gone modern.
Even still it's interesting enough for me to take the time to post in this thread.

Now, if I had your engine, I would change my plans...
You got SO LUCKY!
It could be better, it could be an entire RAT, but what you have there already is what I consider the bottom of the APEX engine scale regarding T4s...

Almost everyone could make 150 hp with that. Someone really good might clear 175.

That LGX I mentioned makes 335 stock with a restrictive exhaust, intake, and a tune more interested in emissions over power...

Now, the LGX means the ENTIRE car requires mods, almost nothing stock is applicable.
It is a HUGE undertaking, a journey fit for a Ninja. (IMG:style_emoticons/default/ninja.gif)

Your kitten could fit right into a stock car...

[Robroe]

Picture of the grooves to drain pooled oil behind rear main seal into crankcase faster. Just used a .10" thick flat file on its edge. Then added a little channel at the bottom of the groove using a triangle file. Now off to machine shop for cleaning block halves and cylinders in cleaning tank.

[Robroe]

Crankshaft end play dilema. When assembled, the crank end play was .045" not .004". Did a mock up of crank in bottom half of case with bearings to see if I could learn anything. The most repeatable end play measurement was .058". I understand this is just a mock up rough measurement, but so far off that I'm concerned about it. The end play shims I have are .0013, .0015 and .0015. Of course these won't fill the .045" gap when assembled.

Here's my question. Since the shims rest against the outside of the rear main bearing (thrust bearing), could the rear main thrust bearing lip be too narrow? Here are picts of the mock up and bearing. If so, how would one order the proper thrust bearing lip size?