Removing the manifolds on an AJP V8 - how easy?

[mikesr]

I'm going to remove the manifolds with a view to getting them welded if the damage isn't too bad.
I know the engine has to be moved about to get enough clearance.

I was thinking of doing it with the car on axle stands and a jack and supporting timber board under the engine.
Engine mounts off, move the engine about and get the clearance to get the manifolds off.

Has anyone done this?
Impossible? Easy?
Don't jack the engine on a block of wood 'cos it cracks the sump?

The alternative is decide the manifolds are scrap before inspecting them and saw them up to get them out so the engine doesn't have to be moved. But I'd rather spend the £1k on other bits. And since I'm planning on treating all the chassis rails around the engine to POR15, self etch primer and a high temp top coat I might as well do the engine mounts at the same time.

And if I'm going take the engine mounts off anyway....

Strange how the simplest of jobs turns into an all winter project


Any advice appreciated.

MikeSR

[JensenA]

I remember reading a thread on here that they are possible to get off with the engine in situ, but loose so you can move it around, so good luck. Hopefully someone who has dne it will be along soon to tell you more.

[jonbarrett]

I also have cracked manifolds and am getting a quote from a local TVR specialit. I'll report on the cost whan I get it.

[jesfirth]

Hi Guys,

I had mine welded a couple of times but my experience is that once they have gone you will just chase the cracks around. I gave up and fitted new manifolds. It can be done by loosening the engine mounts but it is still very tight. Andy at APM did mine

[Mad Mark]

I took mine off recently and had them welded.
Its not a hard job really, just a bit of jiggering about to get them out.
I undid my engine mounts and shifted the engine over to give better clearance.
I do have a pit, but dont think it will be too hard on axle stands.

[Cyclone1]

Mad Mark said:

I took mine off recently and had them welded.
Its not a hard job really, just a bit of jiggering about to get them out.
I undid my engine mounts and shifted the engine over to give better clearance.
I do have a pit, but dont think it will be too hard on axle stands.

Agree with Mark.

When I did mine I cut the old ones out first as they had had various rewelds. We then tried in vain to fit the new ones without moving the engine but without any luck (gearbox gets in the way), we got close (about 5mm ) but just couldn't get the new ones in place without breaking something. In the end we loosened off the engine mounts and shifted the engine over slightly, this gave us enough room to manouvre and the job from there on in was easy.

Jules.

Edited by Cyclone1 on Monday 3rd September 06:39

[Mad Mark]

Thats right, it is a very close fit.
Even with the engine 'loose' so to speak, I still had to jimmy my off side manifold to clear the gearbox.
Also on the near side I removed the oil pipe that comes from the sump.

[SimonSparrow]

Mine cracked ages ago and Andy at APM said that given the pain of removing and welding them it was worth putting on new 4.5 manifolds (the phrase 'bigger bore' sold it to me ).

I remember reading about the ACT manifolds that are in two parts so can be fitted more easily, could be worth considering.

[mikesr]

Yes the ACT manifolds were the ones I was looking at. Nice shiny stainless steel to go with new cats that are definitely needed.

I was trying to not spend money on the manifolds if I can get another season out of the existing ones by welding them.

They are in 4 peieces and can be fitted without moving the engine if the old ones are sawn off.

But I plan on removing and painting the engine mounts anyway.

I think I'll take them off in one piece and then decide whether to replace or weld when I can see how bad they are.

Thanks to everyone for the comments and experiences.

[markh1]

My Cerb is currently at Austec having ACT manifolds put on as the original ones cracked. Luckily I have an aftermarket warranty so I get covered for the first £1000.

I was there when they were taking one side off, it took about 2.5 hours - not an easy job.

The manifolds are about £900 and its about 6 hours labour.

I shall be picking the car up tomorrow night probably.

[markh1]

Had the ACT manifolds fitted. Picked up the car last night and there is a noticable difference. Firstly its louder, it seems smoother to me and the torque is better If you have a spare 12-1300 quid kicking about its worth doing.

[Cyclone1]

markh1 said:

Had the ACT manifolds fitted. Picked up the car last night and there is a noticable difference. Firstly its louder, it seems smoother to me and the torque is better If you have a spare 12-1300 quid kicking about its worth doing.

Probably more of a placebo effect.

If you'd done before and after RR tests then you would probably see that the increase is negligable. Also depends on what map you are currently running and whether it would need further adjustment, but for just manifolds being changed this adjustment would be minor.

Good thing is that you now have manifolds fitted that should last significantly longer than the standard ones and they shouldn't suffer from cracking. Did the rest of your exhaust system (inc cat / decat pipes) bolt back in place or did this need adjustment?

Jules.

[HarryW]

Cyclone1 said:

markh1 said:

Had the ACT manifolds fitted. Picked up the car last night and there is a noticable difference. Firstly its louder, it seems smoother to me and the torque is better If you have a spare 12-1300 quid kicking about its worth doing.

Probably more of a placebo effect.

.............

Jules.

Not so sure, depends on what the potential is, mine picked up around 30hp/20lbs with the manifolds and exhaust, but then again its not standard.

[Cyclone1]

HarryW said:

Cyclone1 said:

markh1 said:

Had the ACT manifolds fitted. Picked up the car last night and there is a noticable difference. Firstly its louder, it seems smoother to me and the torque is better If you have a spare 12-1300 quid kicking about its worth doing.

Probably more of a placebo effect.

.............

Jules.

Not so sure, depends on what the potential is, mine picked up around 30hp/20lbs with the manifolds and exhaust, but then again its not standard.

Totally dependent upon state of tune of the car at time of fitment. But a car that already has short induction, a big bore exhaust and a remap would not reap a further 30bhp and 20lb/ft by just adding a set of manifolds, 5bhp maybe and similar torque (poss 10lb/ft here and there).

Jules.

[HarryW]

Cyclone1 said:

HarryW said:

Cyclone1 said:

markh1 said:

Had the ACT manifolds fitted. Picked up the car last night and there is a noticable difference. Firstly its louder, it seems smoother to me and the torque is better If you have a spare 12-1300 quid kicking about its worth doing.

Probably more of a placebo effect.

.............

Jules.

Not so sure, depends on what the potential is, mine picked up around 30hp/20lbs with the manifolds and exhaust, but then again its not standard.

Totally dependent upon state of tune of the car at time of fitment. But a car that already has short induction, a big bore exhaust and a remap would not reap a further 30bhp and 20lb/ft by just adding a set of manifolds, 5bhp maybe and similar torque (poss 10lb/ft here and there).

Jules.

Granted a healthy mapped car will see roughly 5/10lbs across the board, which if you having to replace your old cracked/split manifolds anyway is well worth doing.

[Cyclone1]

HarryW said:

Cyclone1 said:

HarryW said:

Cyclone1 said:

markh1 said:

Had the ACT manifolds fitted. Picked up the car last night and there is a noticable difference. Firstly its louder, it seems smoother to me and the torque is better If you have a spare 12-1300 quid kicking about its worth doing.

Probably more of a placebo effect.

.............

Jules.

Not so sure, depends on what the potential is, mine picked up around 30hp/20lbs with the manifolds and exhaust, but then again its not standard.

Totally dependent upon state of tune of the car at time of fitment. But a car that already has short induction, a big bore exhaust and a remap would not reap a further 30bhp and 20lb/ft by just adding a set of manifolds, 5bhp maybe and similar torque (poss 10lb/ft here and there).

Jules.

Granted a healthy mapped car will see roughly 5/10lbs across the board, which if you having to replace your old cracked/split manifolds anyway is well worth doing.

Agreed.

[markh1]

My car had a remap recently and is at about 387bhp. Apart from that everthing else in the engine deptartment is standard 4.5 I would quite like the short induction but it seems bloody expensive just for some tubing and some trumpets in the airbox?? (I thought it was about 900 quid to get it done, am I right?)

[Cyclone1]

markh1 said:

My car had a remap recently and is at about 387bhp. Apart from that everthing else in the engine deptartment is standard 4.5 I would quite like the short induction but it seems bloody expensive just for some tubing and some trumpets in the airbox?? (I thought it was about 900 quid to get it done, am I right?)

Not quite Mark,

You can buy the Whirlwind Short Induction Kit for £386, it doesn't include the trumpets as these hoses will fit on the existing ones. You will however need your car to go back on the rollers for another remap.

Jules.

[markh1]

Jules,

What exactly is included in the whirlwind kit? and does it give a noticable increase in power?

[Cyclone1]

markh1 said:

Jules,

What exactly is included in the whirlwind kit? and does it give a noticable increase in power?

It's purely the hoses and the clamps to hold them in place. It is difficult to say whether you would get a noticeable increase in power without another remap. When I first fitted my prototype Whirlwind hoses the car did show a slight increase in power at peak as it moved the peak power figure further up the rev range as well as torque, what it also did was significantly smooth out the curve (standard set-up hoses result in the famous "camel hump effect" in the curves) which in turns help improve driveability of the car and smoother power delivery. This however is further enhanced with an additional remap.....

Jules.