Shortened Mi Manifold..

[nick 3]

As the title really, how much needs taking off of the manifold for it to fit?

 

Cheers,

 

Nick

[Jonmurgie 2]

Noooooooooooooooooo.... don't do it! It's far better (and easier) to move the radiator down a bit. Do a search and read up about it but the Mi16 inlet is that length for a reason

[nick 3]

The conversion was done ages ago with the rad moved and full length inlet(see sig'). I have already done a search and it seems 50/50 on whether it makes much difference (both Maxi and Taffycrook being advocates of the shorter manifold and in my opinion both knowledgable people)

I spun a shell at Donington and I'm getting ready to rebuild the motor to go in my new 205, I have spare inlet that I'm going to get modded and if I don't like it I can put the full length one back on.

 

Anyone know how much to take off?

 

Nick

Edited June 18, 2006 by nick

[Jonmurgie 2]

Fair enough then... give Matt @ QEP a call as he does them so should know how much to take off

[nick 3]

Cheers Jon, never thought of that!!!

 

Nick

[t16ryan 1]

I found with a shortened inlet it seemed hesitatant between 4500-4800rpm, fitted full lengh and moved rad and felt alot faster and smoother, same with a friends of mine as they are made that lengh for a reason,

[Duroc 2 1 Cars]

I found with a shortened inlet it seemed hesitatant between 4500-4800rpm, fitted full lengh and moved rad and felt alot faster and smoother, same with a friends of mine as they are made that lengh for a reason

 

I'd have to agree. I bought one of my Mi's with a shortened inlet manifold fitted. I found that it had good torque v. low down and pulled well after 5.5k, but the middle was a bit lacking. I went back to a standard manifold.

[Miles 331 1 Cars]

Std length is the best all round, Short ones are OK not just as good, But you need to remove around 1" out of the inlet tracks

[petert 586]

I take 50mm off and don't experience any resonance problems.

[nick 3]

Thanks for the replies lads, it's not going to cost a fortune to get done so I'm going to go with it anyway.

As I've already said I will still have the option to go to the std manifold and moved rad' if I'm not happy with it.

 

Miles, so an inch would allow it to fit OK?

 

A friend of mine had the same set up as me (totally std Mi) but with a shortened inlet and our cars were perfectly matched in a top gear roll on from about 40mph, even though mine was always regarded as the slightly quicker car through the gears, this is what has got me thinking about going the shortened inlet route.

 

Well at least I should be able to give a seat of the pants back to back comparison.

 

Nick

[rich_w 0]

Slight thread hijack but i've got a Guttman inlet manifold for an MI16 if anyone localish (to me) who has a mi16 and would like to do a back to back test i'm up for it

[nick 3]

That would be interesting.

 

I had forgot about the Gutmann conversion, have a look at this article which is pretty interesting http://uk.geocities.com/nickmi16@btinternet.com/magazine.htm

 

Nick

[rich_w 0]

Can't get to the pics as the bandwidth has exceed, I will try latter and make a mirror

[nick 3]

I haven't got a clue as to what you just said!!

 

Nick

[C_W 3 1 Cars]

I found mine had a big flat spot 4500rpm with the short manifold too. As a temporary measure you could space the shroud and radiator forward.

[nick 3]

It's already done Chris ready to drop in, but I thought I would have a look at the shorter one just to see.

 

Nick

[taffycrook 2]

I have done it both ways, never had any problems with flat spots.

I have however seen short manifolds that don't fit!!

So be carefull.

In back to back tests the short manifold made a bit more power, due to the fact that peak torque had moved up about 400 rpm, this makes the mi16 pull to the limiter still making power where the std manifold tails off just before.

The trade off is slightly less torque lower down but not drastic. A swing of the cam timing will cure this any how.

IMHO it makes little difference but it is easier to fit a short manifold, the small difference in low down torque doesn't effect the 205 on the road.

[crf450 0 1 Cars]

Something worth remembering when shortening the Mi inlet manifold is that it's almost impossible to avoid an internal mismatch and the only way round this is to have the shortened manifold ported after welding. People who have experienced problems with shortened manifolds may have been running manifolds with a bad mismatch.

 

Cheers Martin

[Mattsav 1]

We remove 2" (50mm) without any problems.

 

As CRF450 says, the inside needs cleaning up after welding.

[KRISKARRERA 2 1 Cars]

this makes the mi16 pull to the limiter still making power where the std manifold tails off just before.

The few Mi16s I've seen go on rolling roads, including the 2 engines I've had, don't seem to be dropping off at all before the rev limiter.

[d-9 0]

Rich, Im from glos and have various MI16s, in the next month or so I'll have a standard mi16 205 on the road if you fancy comparing them. Be nice to do a power run on the rollers really

[nick 3]

To be totally honest I would prefer to keep the full length manifold but I had big issues with the bonnet not shutting correctly on my old 205 and ended up with bonnet pins. My old 205 was a bit bent on the front end anyway so that may not be an issue with the one I have now, but seeing as it's not going to cost a fortune(seeing as my missus is going to get rid of all the porn clogging up Martins pc) to get the manifold shortened, and I have all the parts to go back to the full length one I might as well give it a go.

 

Nick

[crf450 0 1 Cars]

Porn, how dare you ,my pc's just tired.Oh forgot to say nick you may want to reconsider the shortened manifold route,yours has just gone up £50