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?

Is the engine in the car & hooked up to everything? Is there gas in the tank? If so, put 3 quarts of oil in it & start it up. Check the dipstick first. I wouldn't worry about the details if the engine runs smoothly. If it doesn't, then I would. Good luck.

If the engine has never been started, google search “break in oil” and when you start it for the first time, put in 4 quarts, then run the motor @2500 rpm’s for about 20 min.

Then change the oil to daily oil, and change the filter.
I believe Valvoline VR 1 racing oil has enough zddp for these solid lifter air cooled engines.

Good luck!

Rich

Carbs are WAY oversized for a 1.7.

Someone should know what was put in the engine during the rebuild (lots of goodies).

Find out what the goodies are.

There is not a good way to tell without a full tear down.

The cases ALL can be built into very large engines.

Those carbs are better suited for an engine of 2.2l or bigger.

Next place to look for hipo parts is under the valve covers.

Does it have solid bushings between the rocker arms or springs?

Does it have aluminum or steel pushrods?

Does it have valve adjustment screws with little swivels on them?

Does it have dual valve springs with nicely machined spring retainers?

Did it come with a serious header?

Separate straight stub pipes to each exhaust port?

Does it have a degreed fan for accurate timing adjustment?

All of those questions help determine how serious the builder was.

The carbs are suitable for a 150 hp+ application.

A big engine will have large venturis in those carbs. What is the ventiuri size?

That could be as big as 2600 CCs and it would be damned hard to tell if all of the sheet metal was on it.

Thank you for your quick insights. This is my first air cooled. Engine is not in the car. Have stainless heat exchangers and really big pipe exhaust system which is not installed. I’ll pull a valve cover and see if I can address some of those great questions. Are the venturis marked with size? Do I remove them to find the markings?

The venturies are usually marked with the size @ the top,remove air cleaner and shine a powerful light down the throat so you can see .
The number on the stock part is a raised cast in number , I have seen aftermarket ones with the number punched in, if you see 36mm which is standard supplied with the 44's they most likely will not run well as mentioned.
IMO its really hard to find out much about the engine unless you can get more info from the seller ....which appears unlikely in this case ,cheers.

I have a similar situation. Someone put a lot of time and energy into the motor on my '70, but never ran it. I have no idea what is in there, but I suspect it is not the stock 1.7, since it is setup for Megasquirt and the car has a side shift trans. I doubt he went that far but kept the stock bore. I'm gonna pull the heads to measure bore size and valve size. That will still leave me in the dark regarding the cam, but I don't know what I can do about that. Would be nice to know the stroke as well. I imagine that can be figured out with the top end off. On 911s you can tell the stroke by the rod bearing size.

If I had that OUT of the car, I'd chuck it up on an engine stand and go to town...

I'd pull the tin off of it and pull at least 1 head. With the head off I could measure both bore and stroke. I'd have the head in hand and would be able to measure valve size and inspect the ports for work.
I'd check deck height and CC the head.

I'd first "pattern" the cam. Checking total valve movement will give "lift" and (with a degree wheel) I'd be able to verify duration, so I'd have some idea of "what cam".

With deck height, head CCs, bore and stroke I'd be able to determine size and compression ratio.

I'd also be able to determine competence of the engine builder and if it was excellent, I'd feel more comfortable about using the case assembly without tear down and inspection.

The biggest problem with doing it this way is getting the motor OUT of the car.

You're already there...

Dial indicator on the valve spring will tell you a little about the cam.

You can completely pattern a cam out with nothing more than a dial indicator perpendicular to the valve spring retainer and an accurate degree wheel.

There are programs available that allow you to put in valve height vs duration changes at specific intervals (often every .005-.010 ") and the program will be able to create a cam lobe profile "map".

With enough time I can pin a profile down perfectly.

You don't have to go through the BS to get it done that way usually.

Simple total valve lift, total duration, and duration at .050 should allow you to find your "grind" from the published data from our current vendors.

You do this to both the intake and exhaust valve on a single cylinder.

Come up with something different than what's available currently?

You will be able to compare it to grinds that are close and get some idea where your cam stacks up at.

I ALWAYS pattern a new cam as the very first cam I tried to "dial" in had its base circle cut improperly and it drove me BAT-SHIT CRAZY!
I ended up dialing in a bone stock cam to prove to myself that I was doing it right!

Sig Erson took TWO DAYS of my life over a poorly ground cam on a Datsun Z car and I haven't trusted another aftermarket cam grind since.

I haven't found another bad one though.

Once in your life is all the BAD CAM you need!

I ALWAYS check total lift and duration before I try to dial in a cam now.
I haven't purchased another Sig Erson cam since...

The nice part here with both of you guys and your engines is that there are very few options out there for your average builder.
Before you pull the head, measure the camshaft with a dial indicator on the top of the head and a degree wheel on the crankshaft.

Before you go further…post here and probably the samba. Call Elgin.
You will find the motor uses one of maybe 5 camshafts available

Then once you solve that….
Pull heads and measure bore and stroke
Measure intake and exhaust valves

Put it back together.

Check oil pump, post pics to be advised if it’s a good one ( you want a good one)

Carbs…
A whole different set of threads here which we will all help you with…. Once you know what engine you have

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...