2.4 cih head

[yeti132]

Want to build a good 2ltr engine brought a 2.4 Cih head which I was going to use but been told I have done it the wrong way round 🥴 and should of used a 2.4 block with 2 ltr was all so thinking about the unleaded fuel so could anyone give me some advice on building a nice 2ltr to go in a Ascona i2000 please which I am rebuilding at the moment 6 years in 🤔 Got a couple of Kent cams in garage which mite help with the build 

[611]

Maybe its down to the compression using the 2.4 head on a 2.0l block.

Cheapest way i think to build a good CIH is to bore out the old 2.0l block as far as you can. Get the 2.0l head fully ported and some big valves fitted (which will take car of the unleaded) and then get a nice cam for it ENEM.SE do some nice one!

The 2.4 is a costly affair (as i know!) and a pain and the car would have been back on the road years ago if i had stuck to the 2.0l

I had a 2.0l, big valve head, twin carbs, in mine before this and it went pretty good, probably about a 2.1l, about 150bhp ish. I had a mate who had his bored out as far as he could (maybe 2.3?) big valve head, very hairy cam, it was in an early B series and that went pretty quick for a CIH and the bits should be cheaper for the standard engine. Pistons from the USA seemed to be relatively cheap.

Just a few ideas

[yeti132]

Thanks Andy

[Jessopia74]

Yup it’s right 2,4L head has a larger combustion  chamber than a 2L due to the swept volume differences. 
So a very dirty maths way to look at it would be 10% difference in Cylinder cc = 10% drop in compression ratio - there is a bit more to the formula than this but you get the rough idea to see the compression drop. 
The inverse is opposite too, but upping CR by 10% is not a bad thing, just need to use better fuel to stop detonation (pinking), or use less advance (not what we want!). 
The real formula if you want to figure it out properly is 
Swept Volume + combustion chamber volume /divided by/ combustion chamber volume.

I have never used the 2.4 head myself, but I think the inlets sit higher up and might cause issue with clearance if using injection plenum anyway. G
But as Andy has pointed out already, a good 2.0e head can respond well to a very good porting Job, larger valves from the bigger capacity CIH engines fitted and a cam profile with solid lifters.
Fun fact,  old 1.9s cam btw was a bit of a mild road spec when used in the 2.0e due to its profile difference,  but it’s profile was not for hydraulic lifters. 

 

[611]

21 minutes ago, Jessopia74 said:

Yup it’s right 2,4L head has a larger combustion  chamber than a 2L due to the swept volume differences. 
So a very dirty maths way to look at it would be 10% difference in Cylinder cc = 10% drop in compression ratio - there is a bit more to the formula than this but you get the rough idea to see the compression drop. 
The inverse is opposite too, but upping CR by 10% is not a bad thing, just need to use better fuel to stop detonation (pinking), or use less advance (not what we want!). 
The real formula if you want to figure it out properly is 
Swept Volume + combustion chamber volume /divided by/ combustion chamber volume.

I have never used the 2.4 head myself, but I think the inlets sit higher up and might cause issue with clearance if using injection plenum anyway. G
But as Andy has pointed out already, a good 2.0e head can respond well to a very good porting Job, larger valves from the bigger capacity CIH engines fitted and a cam profile with solid lifters.
Fun fact,  old 1.9s cam btw was a bit of a mild road spec when used in the 2.0e due to its profile difference,  but it’s profile was not for hydraulic lifters. 

 

Nice bit of info there 🙂

Yep the inlets sit much higher up, you also have a different thermostat housing on the 2.4 and cant fit the 2.0l to it (i have gaskets if you do need one as had to buy 10!!) and if you did have the injection on you might have an issue, carbs or throttle bodies no problem 🙂

You can see how they sit up higher in the image below and the smaller thermostat inlet

http://www.theopelproject.com/wp-content/uploads/2017/07/IMG_20170826_092630-1140x660.jpg

[lamchop77]

Been a while since I posted on here!!!! The 2.4.head is pretty much the same as the 2.2 head but the exhaust ports are bigger. The combustion chamber as said is bigger than the 2.0 and gives the  10% or so drop in compression. If you want to use it skim the head to raise the compression a bit and invest in Vernier timing gear as you will need to dial the cam back in after skimming, can’t remember exactly but I think 0.1mm skim is a 1 degree change in the position of the cam. The inlets are higher in the head but this gives a big increase in flow. Comes from early tuning of the “Sweden heads” I think. Basically a 2.2/2.4 head starts flow wise where a fully ported 2.0 stops so definitely worth using. You can use the 2.0 injection and manifold it just needs the dowel positions red rolling in the 2.0 plenum and a bit of port matching to fit. Guy I knew ran 2.0 injection on a standard 2.4 and got a 9bhp increase. 2.2/2.4 injection was geared for economy not power.

Hth

Chris

[H-400]

This will be the next thing to do on my GSI, got the 2.2/2.4 head and a cut off 6 cilinder manifold with the 70mm throttle body. Together with a BMW AFM (also 70mm) and L-jetronic feul pressure regulator (3 bar, a LE is 2,5 bar). As you wrote I want to copy the "Schwedenkopf". 

[GTEPETE]

Hi Herman, can you help me with a part number for the 70mm BMW air flowmeter. I nearly bought one on ebay, but it only had four electrical pins... Manta has 5,,,

[Jessopia74]

On 08/07/2020 at 15:55, GTEPETE said:

Hi Herman, can you help me with a part number for the 70mm BMW air flowmeter. I nearly bought one on ebay, but it only had four electrical pins... Manta has 5,,,

Think that’s rather L2 jetronic variant.

think this is the one you want as fitted to 323 etc, can see oem part number clearly.

However , the bmw number can be found https://ecu.eu/bmw/air-flow-meter/bmw-13621284407-bosch-0280202031-129549.html

 

Edited July 12, 2020 by Jessopia74