73 1.7 Project, Engine Updates Options

[Robroe]

Bought a 80% done project. 1.7 engine has been rebuilt and lots of new goodies installed. However I don’t know what heads, and internals were installed. Engine has never had oil in it and looks like jewelry with dual Weber 44s, new heads and powder coated tins. I’m on a quest to learn what I can about this new engine. Other than the carbs, only other info I’ve found is a number 850910 stamped on the heads next to an intake port. Any recommendations on how to learn what I have without taking everything apart?

[technicalninja]

Something that should be mentioned regarding checking cam profiles the way all posters have been suggesting.

The inclusion of the valve gear may alter your readings a small amount.

The "correct" way of dialing in a cam eliminates the push rod and rocker assembly and takes all the measurements directly from the push rod seat in the lifter.

If I was doing multiple T4 I'd modify the end of a push rod to screw directly onto one of the dial indicator tips.

The rocker arms are supposed to be 1.3 ratio but by trying different length pushrods you will find that you can alter the total lift.
All you are doing is changing the angle of the rocker arm.
This tells me that the rocker arms are not perfectly liner in their ratio.

One of Ian Karr's videos show this phenomenon quite nicely. The one regarding pushrod length adjustment.
https://www.youtube.com/watch?v=rPkHNxrvdbs...NVx&index=6

Whole videos worth watching but what I'm talking about is in the 9-minute range.


You can still use the "on the valve spring retainer" location for gross checking which should be enough to determine which grind you have.

When you really get serious about this you will be on the lifter...