Longman Mi16 Manifold Blowing

[Guest hux309]

after getting a grp n lower engine mount fitted i still swear the exhaust has started to blow.....can anyone pleade help me with this as i need it ready for nat day

will getting poly bushes reduce exhaust movement as i feel it vibrating underneath especially upon startup or when reversing......any suggestions as im lost

[fiji bob 0]

the mount will make the exhaust seem alot louder and will probably account for the vibration as well give it a couple of weeks and it will soften a bit but its still too harsh for everyday use imo

[C_W 3 1 Cars]

I'm a bit confused, why would a group n lower mount stop the manifold blowing?

 

btw on mine I had a hairline crack around the base of the flange (downpipe end) that you couldn't hear blowing on idle or slow driving but if you accelerated hard you ould hear it blowing loudly, probably opened up t he crack a bit.

[Deadliest Pug 0]

A good way to help prevent cracks is to shotblast the manifold as smooth as you can. It takes away small sharp ridges which are where cracks start.

 

Dave!

[Guest hux309]

sorry should have explained better...was in a hurry

the pipes at the low end keep popping out and need to be re-bolted...i bought the grp n to reduce movement but this hasnt cured it from what i can see...hence why ive ordered poly bushes for the zorst

 

all i get is buzzing directly underneath...especially when reversing

Edited May 16, 2003 by hux309

[fiji bob 0]

do you think welding the weak spots would stop it cracking?

[Guest hux309]

it isnt cracked...at least i hope not

its the y piece that keeps popping out

[Deadliest Pug 0]

Peroonally i'd steer clear of any welding. Welding pulls the goodness away from the edge of a material unless it's oxyocetalene welding or brazing etc.

 

Not a good idea.

 

Dave!

[Guest hux309]

well ill keep an eye on it for now.....

if it pulls out one more time the jb weld is coming out

[Guest Paul205]

Make sure the system isn't too rigidly mounted towards the back so it is allowed to move slightly...Could also try some different clamps on the y piece, may need more even force around the joint.

[C_W 3 1 Cars]

A good way to help prevent cracks is to shotblast the manifold as smooth as you can. It takes away small sharp ridges which are where cracks start.

 

Dave!

But an Mi16 manifold is mild steel rather than cast.

 

But that isn't an Mi16 manifold!!!

 

I think what you need to do is adjust the whole system so that it isn't pulled tight before you clamp it.

[Guest hux309]

sorry...bad habit....longman manifold......may try using different clamps as the ones supplies look like they dont offer a lot of clamping force....

 

got some facom spanners here so i may see just how hard i can tighten them.....

the exhaust does pull back slightly but it needs to sit like it does for correct positioning...

will have a look at the middle and back box to see if i can somehow lengthen it but tbh i dont think this will make much difference..

Edited May 16, 2003 by hux309

[C_W 3 1 Cars]

sorry...bad habit....longman manifold......may try using different clamps as the ones supplies look like they dont offer a lot of clamping force....

 

got some facom spanners here so i may see just how hard i can tighten them.....

the exhaust does pull back slightly but it needs to sit like it does for correct positioning...

will have a look at the middle and back box to see if i can somehow lengthen it but tbh i dont think this will make much difference..

Usually on a sleeve fit exhaust yo udon't need to be that tight with them as the first sign of clamping is normally tight enough. Normalyl if you overtighten them it dents them and makes ita pain to get off.

[Guest hux309]

well went for a drive and it didnt get any wrose so it must be the group n mount bedding in.....

on a bizare note i thought my clutch release bearing had gone through the housing only to find it was the cable broken as it was running on the ground......god i hate garages right now

[Guest mikie]

Is it the two pipes that are pulling out or the one to the rear? I have the same manifold & got the rear joint welded its been good since.

[Guest hux309]

its the two pipes...dont like to weld...usually last resort..but it seems ok...if not very buzzy

just getting some poly bushes for the zorst to reduce movement as i can feel it bouncing along sometimes..

Edited May 17, 2003 by hux309

[Guest DAZ_C]

it sounds to me like the back section is to short in some way, I presume you cut the middle section to fit the bottom piece on ?

I have the exact same manifold and have removed the springs off the joint and just clampped it up with big bolts and nuts and I haven't had that problem at all -I mean mine would be alot more riggid with not having the springs come flexy joint on. Would say that if you weld the Y piece to the downpipe bit then the movement thats causing that to come off will just be transfered further up the manifold and may brake the exhaust bolts holding it to the head or damage the manifold (if you know what i mean). Suggest finding the cause of the problem before makin a cure.

[Guest hux309]

well ive been lucky so far...the mount seems to have worked....