Decisions On Mi16 Manifold

[Jonmurgie 2]

Right, I've got a 4-2-1 Mi16 manifold that I've had for a year or so... it was bought second hand and served me well but not long after fitting the Jenvey's & MoTeC the manifold cracked between the join of the outer 2 sections. The guys at PowerStation were confident it could be welded up and proceeded to do so. This meant the 2 sections had to be split so access could be gained to the crack.

 

With this done I wrapped the system and left it in the garage until this weekend when we came to final fit the engine in the car, knowing that there are only 2 ways to get the complete system in the car (engine out or subframe off) we put the new studs in the head and offered up the manifold, only then did we notice that as the system had been split, and re-welded together there was an issue between the 2 sections which meant they would not slide over the studs... we tried several things to maneuver the manifold on but ultimately were unable to get all 9 of the studs through the manifold no matter what we tried.

 

The long and short of it is that we put the engine in with no manifold as I wanted to get some progress made. This means I now have a 4-2-1 manifold that doesn't lineup and needed to make a decision on what to do. The options as I see them are as follows:

 

1. Try to re-weld the 4-2-1 manifold once again

Issues with this are that it may be a lot of wasted time and effort and with the engine in the car it means a LOT of work to check unless I get a foocked Mi head to test fit. Also, I had the Y piece (the 2-1 section) welded up as the brackets were loose and the system was blowing. This now means the system can't easily be split again. Up side of this option, though, is that it could save some dosh!

 

2. Buy a new 4-2-1 manifold

Easiest and no doubt the best solution would be to simply buy a new 4-2-1 manifold, problem is I totally can't afford to do this right now so it means a long delay in getting the car running. The manifold I currently have was cheap when I bought it and it was a bit of a gamble as to whether it could be fixed after it cracked earlier this year so I guess maybe it's just had enough and it's time to move on from that one?!

 

3. Fit a standard Mi16 manifold (with angle plate)

This is an option that I only thought about yesterday... basically going for the standard Mi16 manifold and re-angled plate then coble together the rest of the the exhaust as I'd need a downpipe etc. This seems the most cost effective way of moving forward and getting the car running. My BIG issue with this though is what effect is may have on the torque/power of the engine....

 

So one of my main questions is am I being completely foolish to think I can run with a standard Mi16 manifold in a high-powered application? Does anyone have an idea on what the max BHP the standard manifold can cope with?

 

Using a standard manifold would only be a short to mid term thing, until I could afford a proper 4-2-1 again... I'm just keen on getting the damn thing back together and on the road!

 

So any thoughts please guys

 

Cheers

Jon

[hman205 1]

Jon if needs be i can lend you an mi16 head to do the test fitting on then you can go ahead with option 1

 

but if not option 2 is probabbly the best option

 

BTW im in Bristol if thats any use to you?

Edited September 18, 2006 by hman205

[Jonmurgie 2]

Having just discussed it with PowerStation I'm going to take you up on that offer and will drop you a PM

[steve@cornwall 100]

I have had a couple of 8v manifolds crack and afterward the manifold studs have been pulled out of shape so as not to fit onto a good manifold, are you sure all of your studs are still straight?- wouldn't it be nice if it were that simple?

[Jonmurgie 2]

It's a brand new head and new studs... it's the manifold that's the issue, I will get a pic

[taffycrook 2]

I have run std exh manifolds up to 190 bhp. The design is far from perfect and no doubt more power could be made by using a proper manifold. However if the engine flow doesn't require it then it could be money spent better elseware.

 

I have no idea of the specs of your engine so I can't answer for sure but unless its a 200 bhp animal try the std manifold it may surprise you.

[Jonmurgie 2]

It's going to be plenty over 200bhp so I'm going to try my best to save the one I have, otherwise buy a new one...

[Mattsav 1]

Either fix the existing manifold or buy a new 4 branch.

 

 

The std item will strangle that engine.

[Dazza 4]

Jon if its any use i can have you a new bolting flange in mild or stainless steel made up perfectly ,cut by plasmer cutter so its amazingly accurate and this would leave you with welding the 4 branch to the flange only .( If you can wait a ccouple of weeks )

If iam on the right tracks couldnt you file out the offending holes to fit over the head bolts as iam suspecting it cant be to far out although reaching and seeing down the back of these engines is near impossible unless you use a mirror to see there ?? Is it a one piece exhaust manifold gasket similar to the iron Mi 16's as there's a template for you ?.

Let me know .

dazza

[welshpug 1,657]

it would be interesting to see what effects the standard manifold has on an engine of that tune seeing as you've had a power run with the aftermarket manifold.

 

what sort of power did you get at the last mapping?

[Jonmurgie 2]

The std item will strangle that engine.

Cheers Matt, I was gonna give you a call before I made any major decision to go for a standard item... but as you say it will no doubt kill power as I thought

 

Dazza, thanks for the offer... we're going to try and match the manifold up to a spare Mi16 kindly loaded by hman205 first and see if that works. Failing that I'll get in touch!

 

I've never had the Mi6 on the dyno with a standard manifold so I can't actually compare that

[James_R 3]

Option 4 would to have an totaly new exhust manifold made up as per the spec of your engine rather thana generic tubular job used on std to hot engines, which is not ideal, although as ever cost is an issue and it's not a perfect world, but after spending X thousand on the engine to skrimp on the exhust seems silly?

 

Hope you get it running soon though

 

James

[Jonmurgie 2]

Cheers James, I guess that would be ideal and something to consider in the future when funds allow... what kind of places are able to do that then, something that will actually WORK rather than somewhere like Powerflow who just stick bits of pipes together (I realise they don't do manifolds though)?

 

Cheers

Jon

[James_R 3]

BTB, Tony Law, Simpsons

 

I've only seen a simpson system first hand, stainless tig welded, was an awesome bit of kit, full system on a single repackable box, not cheap, but not a powerflow by anymeans. Talking aroudn 1000 price tag whihc compared to the other company I named are fairly cheap.

 

Also Ashely perf exhuasts would be an option, I've used then numerous times for one off stuff and it's not to the same standard to those, is effective and lasts well, that woudl be around 500 for a full manifold and system hand built for the car, around a weeks turn around.

[taylorspug 7]

Id recommend BTB, as they did an amazing job on my VR6 manifold a few years ago, was a work of art and gave proven gains, not cheap though.

[Jonmurgie 2]

Right, good news is that we managed to sort the manifold out today with a BIG thanks to James (hman205) for letting me borrow a Mi16 head last night

 

So, all systems go for this manifold, finished off wrapping it too:

 

hooray, mini-disaster averted as we managed to save the 4-2-1 Manifold this afternoon. With the use of a vice, welder and some persuasion (and the borrowed Mi16 head from James aka. hman205) we've straightend everything out and it's all fitting nicely:

 

 

 

 

[smckeown 1]

superb

[Kitsune 0]

not cheap though.

 

 

BTB Mi manifold (Spoox/TRC 205). £2500.

 

Good work Jon. Cant wait to see this in the flesh.

[Dazza 4]

BTB Mi manifold (Spoox/TRC 205). £2500.

 

Good work Jon. Cant wait to see this in the flesh.

You Bet .it should be quick as there's all the right stuff around it ......

Dazza