292 cam in a 1600

[halboyles]

41 minutes ago, Preyupy said:

You will run into a giant step between the manifold and head.

 

A giant step indeed.

[Preyupy]

You are comparing the carburetor end to the cylinder head end of the manifold there.  You need to compare the port match between the manifold and the head.  put the gasket on the head and see how it fits then try it on the manifold and see if it fits exactly the same. 

[halboyles]

42 minutes ago, Preyupy said:

You are comparing the carburetor end to the cylinder head end of the manifold there. 

 

I meant to do that!

 

 

 

 

Actually I screwed up!  Anyway here are the pertinent measurements (first two manifold measurements are 1600/1800, second two are 2002).  I believe neither the heads nor the manifolds have been ported.  Also the measurements are approximations.

 

Now, I gotta go ride my Roadmaster Supreme.

 

 

 

 

 

[Oldtimerfahrer]

The 292 should be an improvement, assuming you do get the compression you are planning. BMW achieved the hp gains with carbs and compression, adding the cam is only a benefit. I have the 300 cam on a 2002ti with 45's and it's very driveable. Everything up to 300 is very driveable in traffic, you hardly notice the "lumpier" idle which you can't dial out without making it undriveable. I don't know if the 1600 loses its smoothness...but I doubt it. You'd need a radical cam and even higher compression and 45's to ruin it as a street car.

Good luck!

Andrew

[Preyupy]

it looks like you probably have the correct manifolds for the 118 head. 

[halboyles]

1 minute ago, Preyupy said:

it looks like you probably have the correct manifolds for the 118 head. 

 

Yes, I use these on my '71 1600.

[Preyupy]

Then this is going to be easier.  I have seen more than a couple of people just take manifolds and bolt them on without checking and discovered it ran horribly. They kept changing jets and playing with the distributor and could never get it to run worth a damn.  Then someone found out there was a 3mm step all the way around each port (in the wrong direction) and there was fuel laying in a puddle at the bottom of each runner. 

[halboyles]

23 minutes ago, Preyupy said:

Then this is going to be easier. 

 

I was actually responding to the PO's request about using sidedrafts.  I, personally, have been messing up sidedraft installations ever since my first 1800ti!

[mccusername]

OP here. I have tracked down correct 1600ti manifolds-- it is tricky, though. Most of them I came across had been bored out to work with the 2 liter, which is a damn shame. I also found some 1800ti ones which would work, but I'm being picky about appearance.

Thanks for all the opinions on cams-- decision day tomorrow.

[halboyles]

1 hour ago, mccusername said:

correct 1600ti manifolds-- it is tricky, though

 

Very much so.  The 1600ti intake manifolds have distinct part numbers and do not have the vertical post of the NK versions.  At least in what I've seen.  But there must have been transitionary versions that might be a cross between the NK and the "M10" ti.  

Here are some pics of a genuine 1600ti set from 1968.

Edited March 1, 2019 by halboyles

[mccusername]

For everyone who's on the edge of their seats-- I'm going with the 300 degree Motorsport cam. Everything else I'm doing is period correct so I think it's cool that you can still get the cam that BMW and Alpina offered as a performance upgrade at the time. With the DCOEs tuned properly and a 123 distributor, I'm hoping I can still get a smooth engine. Will update.

[Harv]

I ran an Isky 300 copy (used valve lash caps) on a 2.0 121ti head with 46mm intakes. This along with 40DCOEs and 9.7:1 gave a decent idle and would pull 6000 in 4th with a 364 rear. 

 

John

[Oldtimerfahrer]

I have used the Motorsport cam in a 2-liter for the last 15 years, nothing wrong with it. I had a good head that came with the cam already installed in the good old days of ebay. When the cam went south due to a material defect on one of the lobes a few years ago, I bought another one because it was cheaper that getting a new head due to the large journals. I got an object lesson from another FAQler that the 300 degree cam is very out and not comparable to a modern cam...Everything is possible, but once you line-bore the head out to the larger cam journals of the Motorsport cam there is no return.......at least not economically viable return.

You can dial it in with the right chokes (venturis) to achieve either low end driveability with no top-end, or all out with a weak lower end and music later on. If you are using the 40's, try to find someone who has a largeish collection of jets and tubes so that each swap isn't a financial exercise. The Venturis though probably are not an item that you happen to have lying around in many sizes.

[WVGranat]

5 minutes ago, Oldtimerfahrer said:

. I got an object lesson from another FAQler that the 300 degree cam is very out and not comparable to a modern cam...Everything is possible, but once you line-bore the head out to the larger cam journals of the Motorsport cam there is no return.......at least not economically viable return.

 

It's not like Dr. Schrick has been working on the 292 or 305 anytime recently either.  They are all "old" tech and depend heavily on the set up.  Ironically I think the greater velocity afforded by the smaller 118 ports may actually benefit the OP in balancing low-end and top-end performance.  Your going to be reving up there anyway with a 1600.

[mccusername]

1 minute ago, WVGranat said:

Your going to be reving up there anyway with a 1600

 

Yes, I think that's part of the fun and a characteristic of the 1.6 that I want to keep. Otherwise I would have just gone with a 2 liter. I don't mind power being moved up in the rev range but I do like a smooth idle so hopefully will be able to tune for both.

Re: the smaller ports of the 118. I know Alpina sometimes bumped up the size of the intake and exhaust valves a little bit when they modified the 1.6 engine, but I'm debating that. More flow but less velocity?

@Oldtimerfahrer One of my concerns with the 300 cam is that you can't go back to a stock cam in the same head. But this engine block is not original to the car anyway, so I figure if it ends up being too aggressive for me, I can sell the engine and try something else.