Carb/Exhaust Configurations for Dyno test

[jdoclogan]

Getting closer to a Dyno test on Street and Race 1592 engines.
These are the Carb configurations:


Left to Right:

32/36 Weber
38/38 Weber
38 Weber DOCEs
40 Dellortos
45 Weber DOCEs

I will also test three different exhaust headers:

My 4 into 1


Atalla header and stock header

 

[husky drvr]

jdoclogan,

Would there be any possibility of including the cast iron exhaust manifold and down pipes with the 32/36 tests for a baseline reference? There are so many using that combo, there will probably be a bit more interest generated for people who might be considering a change.

I realize scheduling for any project like this can rapidly become "hectic."

Thanks for your consideration,

 

[DanR]

My 4 into 1

Doc, I really like the looks of your 4 into 1 headers. Very nice and neat loooking.

 

[alpine_64]

Jerry,

Looking great.. also take note of the various choke sizes and jet size in each configuration for each run to compare changes

I note you have rare 38DCOE and your 40 setup are dellortto not weber so that may create slight variation across the 38/40/45 comparison

 

[jdoclogan]

Jerry,

Looking great.. also take note of the various choke sizes and jet size in each configuration for each run to compare changes

I note you have rare 38DCOE and your 40 setup are dellortto not weber so that may create slight variation across the 38/40/45 comparison

Yes, 38DCOE is rare. I had and may still have access to NOS in the box 38s. 38s are the same body as 40s except for 38 vs 40 outlet.
Dellortos are virtually the same configuration as the Webers.

I'm taking note of setups.

jdoclogan,

Would there be any possibility of including the cast iron exhaust manifold and down pipes with the 32/36 tests for a baseline reference? There are so many using that combo, there will probably be a bit more interest generated for people who might be considering a change.

I realize scheduling for any project like this can rapidly become "hectic."

Thanks for your consideration,

I put cast iron in pile.


This is my professor question of the day. Curious, where did you get the "there are so many using that combo?"

 

[bernd_st]

Jerry, terrific combos you have there so very much looking forward to see the actual dyno readings. My best bet on a 1592 would be either 38 or 40 DCOE's in combination with your 4 in 1. From all around driveability, responsiveness and mid range torque point of view I'ld put a bet on the 38's. Let's see. Think you know that, but in order to achieve optimum mixtures/jettings best would be to put a Lamba sensor into each of the exhaust headers...

 

[husky drvr]

This is my professor question of the day. Curious, where did you get the "there are so many using that combo?"

Well gee professor,

No hard data, but a plethora of observations, such as, of Alpines for sale with owners expounding a conversion to W 32/36, a number of threads asking how to tune the W 32/36 (ever recall a thread here asking "How do I tune my Solex B 32 PAIA carb?"), and finally, the knowledge some s3's and all sIV's are just a part replacement away. Series V's would need to change the intake manifold as well as the carb and linkage. Ever notice when a thread is questioning about drivability and tuning of the original carb systems, there is almost always a response or two chiming in advising a change-over to the W 32/36? As parts for the Solex go away, there will be more conversions in the future.

Just some random thoughts,

 

[jdoclogan]

Agree with your last thoughts Don. However, I will test the 32/36 against the 38/38. I have run both and by the seat of my pants I think 38/38 is giving me a better sensation of power.

 

[jdoclogan]

Don, after a thorough investigation into the cast headers my findings determine the cast headers to be a horrible component. Rootes must have been dropping their quality control. Note my following findings:

I took three cast headers from my parts pile.


I measured each inlet and discovered they all have a poor casting outcome on 2 and 3. Note my yellow markings at the defective area


In addition there openings were smaller than the outlet on the heads I randomly measured from one of my piles.


Here are the measurements:
All cast components had .88 (+ or - .06) inches on cylinders 1 and 4 inlets and .68 (+ or - .03) inches on cylinders 2 and 3. All heads had all outlets measuring .9 (+ or - .01) inches. This leaves a flow problem (particularly at cylinders 2 and 3) at the junction of head to cast header with a restriction of .02 inches for 1 and 4 and up to a whopping .25 inches for cylinders 2 and 3. There is already a flow issue with the heads that Vizard mods and valve sizing can address. One could grind out the cast headers orifices to match the head sizing. I just don't see any value in comparing these headers to the Logan 4 into 1 headers with a 1 inch inlet. Series 1 and 2 Alpine stock exhaust header components consistently provide a 1 inch inlet opening as well. So to compare a Y header system provided by the Series I and II s to the Logan 4 into 1 will provide information as to any value of the Logan 4 into 1.

 

[husky drvr]

Jerry,

Oh well, it was worth asking.

I wasn't trying to suggest the cast manifold was a competitor with the headers, stock or yours. Only that giving that setup a run as a stock example, you would then have a defined start point. A point you could define as the the start of your journey to show how the different stages have progressed.

Also, I'll admit a curiosity just to see what that assembly does produce. IIRC, the only people who actually do dyno tests, and post the results are interested in top performance, the cast manifold is automatically out of contention - no results.

As to your examples of cast manifolds, they do seem a bit "rough." The raised bar in the #2 and 3 ports are there for a reason, either supporting and keying the core for casting or as a reinforcement for the fastener access flat on the exterior of that port, maybe both.

I measured a sV version of the cast manifold and a sV and a sII's head exhaust ports and found the heads' ports to be 1 3/32" and 1 1/16", respectively. The manifold's ports were 1 1/8" at the port surface, larger than either head's ports. Yes, there are areas that could be improved by a bit of grinding. I'm just not sure how thick the casting is at those points.

Thanks again for your consideration,