Performance Cylinder head for Series?

Hi,

has anybody experience with "performance" cylinder heads, especially with the ones from

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?

As I have the rebuild the head of my petrol 2,25 IIa this winter I am thinking about buying a performance head. They claim a power and torque increase *without* any further modifications. As a regular engine tuner (motorcycles, Mini, etc.) I am basically not a newbie to engine tuning, but I don´t know anything about performance enhancements on the old 2,25 lump.

As I drive my 109 through the northern sahara I would appreciate a little bit more torque over the whole rev-band and a little top end power plus. The head they sell has 1:8 compression so this would be no problem for my africa journeys.

I basically don´t want to alter further enginge parts because I would like to conserve the reliability and repaireability of my old friend, so a head which alone brings a little bit more power would be nice.

Raoul

Reply to
Raoul Donschachner
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the 2.25 is very well engineering and understressed and will take a lot of modification without losing its reliability. if you are going to change the head (which i believe gives about 10bhp extra) you might as well change the camshaft for one of their uprated ones. Might as well change the exhaust and inlet manifold too! So i`ve been told, with the modified cylinder head, cam, exhaust and manifolds you will get about 90-95bhp without losing low down torque or reliability. If you drive at the same speeds as you did before then you should even get better fuel economy. Just make sure the bottom end of your engine is in good condition and you have good oil pressure etc (basically the same things you`d check on a mini engine before modding it) automotivecomp have a good reputation in the UK. Hope this helps.

nick c

Reply to
Nick C

Hm, would be nice, but then I would have to do a complete rebuild which is not necessary at this point of time.

Nice to hear that, I will see and tell :)

Raoul

Reply to
Raoul Donschachner

My mate has a lot of the automotive kit on his 2.25 engine. He has the head and the cam, along with the fancy exhaust manifold, and the inlet manifold with the SU carb (is it an SU?) I dont know what its got now in terms of HP, but its bloody fast!, and sounds good! (hes got a cherry bomb on there too). It goes off the speedo without any trouble, which is impressive (the needle keeps going round!) I dont think its any more un-economical than before, and its definately just as reliable.

If i were doing it, I'd rebuild the bottom end of the engine at the same time. When we put his together the bottom end looked a bit worn (the pistons moved a bit), but we left it alone. 9 months later and its getting pretty knackered now! (knocking somewhere). will find out what it is when he gets round to pulling it apart again (I think he's tempted by a bigger block next!)

He didnt have any trouble with automotive, except that the courier firm they use is crap. They actually rang up this week to collect the old head!, and the courier came round to get it, but apparently didnt give enough time to get down the stairs and answer the door before scarpering. They had his phone number but didnt ring it (its even on the note the courier put through the door!). I think most courier/delivery firms are crap though!

Reply to
Tom Woods

Many years ago, I was looking to replace the original unleaded head(8:1) on my early 90(2286cc) purely for the hardened valve seats, and influenced by the claims of the company regarding their "stage 2 head", I paid the extra to have one of those.

Although they said it had made a difference, I personally, could never detect the slightest improvement.

With hindsight, I wouldn't have bothered paying for the "performance".

Neil

Reply to
HN

Indeed? You bought a Stage II head but did not alter anything regarding manifold, carb or so? Maybe this would have been the point, as the stage II seems to be modified in a way where the engine needs improved surroundings to give an extra horespower.

Raoul

Reply to
Raoul Donschachner

you`re spot on there Raoul. There is no point having a high flow, high output cylinder head if you`re still sucking in the juicy stuff through a drinking straw! The induction is the main restriction in any engine. You restrict the induction and it doesn`t really matter what engine / exhaust combo you have, it won`t make much difference. The first thing you must do to increase the performance on any engine is allow it to breath to the engines maximum potential. Once you have that you can then move onto the engine itself and allow a higher flow rate through the cylinder head. Check out the VW beetle for instance, massively restrictive carb and manifolds, same with the exhaust. Change the carb and inlet for a nice webber item and bang on a decent exhaust system and put it on a rolling road for a proper tune up and you can bump the engine output by about 40% with no engine mods! My 1302s `71 ran like a dream after doing just those 2 mods and was happy to cruise at 65-70 all day long! They were built purposefully restrictive to ensure huge reliability and economy - same as the landie 2.25 engines. Shame that they sold you the modified cylinder head without first telling you this simple bit of tuning advice........

Nick C

Reply to
Nick C

Nobody sold anything to *me* I think the point is, that there are two different versions of performance cylinder heads from these guys. Stage I is supposed to work without further modifications, for which I was seeking a reasonable proof, and the stage II obviously can´t run properly without more in- and output than the original manifolds and carb can deliver.

Raoul

Reply to
Raoul Donschachner

It was I was sold the head, not Raoul! :o(

As I said it was quite a few years ago.

At that time, I was really only looking for a lead-free head for my

2286 engine. I know that the company were claiming performance improvement by virtue of the Stage II head alone, without alterations to other parts of the fuelling system. In fact I think I may even still have the original advertising somewhere. But that's beside the point, as they didn't recommend, or even suggest that I purchased the other tuning bits anyway.

So, as I considered them to be the "experts", I took their advice that was offered.

If I can dig out the original sales blurb, I'll verify this.

Neil

Reply to
HN

This would be very unprofessionel from them :-/

Raoul

Reply to
Raoul Donschachner

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