17 replies to this topic

[Harwoods]

As stated in title, while attempting to fit our new exhaust manifold (C-AEG365) with our existing CAM6618 inlet manifold there is a clear issue with fitting. Whilst tightening the nut+washer down on the stud, the washer tightens down onto the inlet manifold side but is a clear 1mm clear of the exhaust manifold.

Tightening any further results in an angled washer and possible stud bending as shown below, still not securing the exhaust manifold:

 

Is this a defect with the manifold we purchased? Are there different thickness of the flanges on the exhaust/inlet?

As far as I can measure our old exhaust manifold was the same 7.5mm~ as the new one in thickness.

We're using the same studs+washers as before, just got the new nuts as ours were well past there time, as seen below for comparison:

 

 

Any help/advice would be greatly appreciated. Thanks in advance.

[cal844]

You need to make stepped washers

[I hate Brian]

Why stepped washers just recess the inlet manifold  ? must be easier 

[cal844]

That could be done but difficult to get it right

[Harwoods]

You need to make stepped washers

 

 

Okay that sounds like somewhat of a solution, but still doesn't explain the route of the problem.

Why are they making 2 different thickness of flanges on the exhaust manifolds? Or is this just an issue of manufacturing? 

 

Why stepped washers just recess the inlet manifold  ? must be easier 

 

I wouldn't like to do any irreversible work to the original spec. Otherwise if I needed to replace the manifold again then my inlet might be too short of a flange.

Thanks all, any other info on the cause of the problem would be great.

[Harwoods]

Upon researching the "stepped washer" suggestion I have found this article relating to the modern equivalent inlet manifold sold on minispares.

http://www.minispare...old-information

 

"The flange thickness variation can cause poor sealing of the manifold resulting in air leaks into the induction system and blowing exhausts."

"Initially the obvious solution is to grind whichever manifold has the thicker flanges down to match that of the other - but when attempting the fitment on a weekend and without the ownership of a decent mill in your garage, it is the hardest to achieve. The other option then is to counter this inconvenient 'step'."

The options listed on this page all seem awfully involved for parts that I expect to just bolt on. Any other suggestions on if we have bought something incorrectly would be much appreciated.

Thanks again.

 

[richmondclassicsnorthwales]

Use or make shims from metal sheet to sit in on the lower side. (gap side)

 

You just don't need the gap or it will blow an awful noise on the exhaust side, reversibly, if the gap was against the inlet manifold and not the exhaust, then you would be sucking in too much air and it just would not run correctly at all

 

If you tried to take away the excess on the inlet, you would have to absolutely spot spot on

 

By the way - make sure you use the large washer on the faces first, / and / or / then a small flat then spring / lock washer not just a small flat and then the brass nut

[Harwoods]

You just don't need the gap...

...If you tried to take away the excess on the inlet, you would have to absolutely spot spot on

Agreed.

 

By the way - make sure you use the large washer on the faces first, / and / or / then a small flat then spring / lock washer not just a small flat and then the brass nut

Not sure about this, the larger washers would fowl on the welds of the exhaust manifold where the flanges are welded on.

Our engine is tuned to 1380 and from what I understand has a MG metro inlet manifold, which by the looks of things minispares has a different manifold for, not the one we have ordered...
C-AEG366:

https://www.minispar...|Back to search

C-AEG365 (What we ordered):

https://www.minispar...|Back to search

 

Not that minispares has the best catalogue of images for each product, anyone have any idea how they have achieved: 

"With half washers on back of flanges for the extra width of the original CAM6618 MG metro inlet manifold."

Are the half washers welded onto flanges?

Anyone know what returns/exchanges are like with minispares...

Thanks again.

[richmondclassicsnorthwales]

Think you may have to do a bit of mix and match, and use parts which do the job with a bit of adaptation.

 

Nothing wrong with a bit of adaption, you need what works and will do the job, it's not a bodge, it's a necessity.

 

Just putting the ideas in the pot. I've had to do a few things over the Years, especially early 80,s when replacement parts were NLA

[sonscar]

Its a classic car catered for by many different sources.Classic tinkerers are overjoyed to have to "fettle" parts to make them fit.Seriously it is very poor but I would fire up my welder and make some stepped washers,hours work.Steve..

[cal844]

What I usually do is weld the half washer to the full washer to stop it falling out as you put it in place

[Spider]

The few times I've come up against this issue, I've done V shaped Washers so that when done up, there's a more even pressure across both flanges.

[Earwax]

Not only will you likely find the need for a step on the washer ( my vote goes to this solution), you may likely find you need to grind one or two of the washers for fitment across their diameter- i have 3 round washers, and two shaped like a D, and one closest the water pump end that fits easiest without any washer ( on the end of the header pipe alone) . As above, it is a bit of a grumble, but in the end these engines have had so many different headers and manifold combinations put to them that the easiest thing to do is accept it as a workable solution.

[jaysmini1983]

I did a bit of both, i filed the back side of the inlet manifold flat to remove the washer recess, then welded straight to the washer and dressed that with a file to make a nice stepped washer.

[Mini Manannán]

We made up a set of stepped washers for mine as well.