Inlet manifold help

[stonedrive]

Hi everyone, trying to get manifold off but previous owner has stuck it with what looks like black sealer. I’ve tried everything I can think of to break sealant but to no avail. Any suggestions would be greatly appreciated. Cheers Steve

[DJT]

Having previously used Stag Wellseal to fit an inlet manifold, it took a fair bit to shift it a few years later. I - carefully - used a crowbar between the underside of the manifold and the top of the water pump housing and levered it off.

[stonedrive]

Hi DJT, yes tried with crow bar but it’s stuck solid, I have also tried hitting it with a length of wood and lump hammer. Do you think heat would help. Cheers Steve

[jbuckl]

Well seal is a weak bond compared to polyurethane, which is gap filling and very structural. (Akin to windscreen adhesive)

Use a bar underneath the front of the manifold to prise upwards.

the location should be above the water pump casting.

a wooden wedge can also do the job too.

are all 12 bolts out? Sorry if that’s a sucking eggs comment.

[stonedrive]

Many thanks for that I will give the wooden wedge a go tomorrow. Cheers Steve

[Edmason]

Acetone will soften polyurethane. Obtainable from paint shops. I'd try wrapping blue roll or kitchen roll around the joints, drizzling acetone onto them, and covering with cling film to reduce evaporation overnight. Then try pry bar.

[APS]

Acetone will soften and even melt a lot of things, including cling film. But it is a good idea to try to reduce its evaporation if you can. Probably tin foil wrapped around would help a bit, but the manifold is an awkward shape to cover.

Just be extra careful that you do not drip acetone on your paintwork. Be prepared to have to repaint top of the engine block.

Acetone, aka nail polish remover. Can be bought in fairly large bottles from suppliers on ebay and the like. Or for the small amount you need to see if it works, raid your wife's make up draw.

[wilf]

"Or for the small amount you need to see if it works, raid your wife's make up draw."

You obviously like living dangerously...........

[stonedrive]

Many thanks everyone for your support but problem now sorted, put a wedge at the front a few wacks with a hammer and it came away. The small openings were clogged up with black mastic which I have now cleared. Now got to clean everything and source new gaskets. Many thanks Steve

[jbuckl]

Buy 2 sets of inlet manifold gaskets.

avoid the poorly cut ones.

pictures are available on here.

at least 3 thicknesses seem to be available.

clean and check all the threads in the heads.

(5/16” unc originally)

sometimes require thread repairs.

consider new bolts.

check the leaks weren’t from the pump…. (Staining at the pump vent)

if they were, now’s the time to pull and rebuild the pump.

Tigerseal or other brand (MHP) of polyurethane sealer works well for manifold joints on previously poorly fitted heads …. Slightly bodgy but mitigates for previous poor work.

[DJT]

Set the manifold in place without gaskets and check that all four faces sit flat against the heads. Use engineer's blue or similar and look for witness marks. Use a long flat file or similar to ensure faces are flat and parallel. Then use quality gaskets and sealant. My preference is Stag Wellseal with Payen gaskets.

[jbuckl]

Set the manifold in place without gaskets and check that all four faces sit flat against the heads. Use engineer's blue or similar and look for witness marks. Use a long flat file or similar to ensure faces are flat and parallel. Then use quality gaskets and sealant. My preference is Stag Wellseal with Payen gaskets.

That’s ok and good advice.

Have been required to fix inlet manifold leaks where the head draw down sequence has not been followed previously.

well seal won’t fix that.

filing probably won’t either.

correction without head movement is aided/ possible with pu sealant.

yes it’s better to move heads, but many owners don’t wish to go to that level of work.

[stonedrive]

Many thanks for all advice. Cheers Steve

[wilf]

When refitting my own inlet manifold after a pump repair, I found I could only get all the bolts started if I used the "thin" gaskets from Paddocks, these can make the difference between completing the job or not. I simply could not get the bolts started with the thicker Payen gaskets. It is perfectly sealed these days, I used a combination of Wellseal and black PU sealant (very sparingly, and only around the actual waterways). I also helicoiled every thread in the heads.

Good luck.

[jbuckl]

Manifold clearance holes can be drilled out to help … (also a bodge) sometimes required though.

Recommend a maximum diameter of 9.5mm.

10mm is possible, but the shallow bosses become too weak and skinny at 10mm and distort…. Compromising the clamping.