bankz5152

bankz5152

Well-Known Member
Been having a read on a few dead threads around the web about inlet/exhaust manifold porting but as the threads are dead there is only mis-matched information, so thought I'd ask here!

So anyone done it? Worth doing?

Mainly interest on the inlet side as that would be very easy to do, though I'm sure it's not as simple as grind out some of the inlet manifold!

Cheers
 
So anyone got any advice on TD5 porting?

Been offered a good head for little cash to give it a go.
 
I had a go at it once using a dremel with a flexible drive thingy. Standard heads have quite rough ports caused by the initial casting so the idea is to remove as much of the roughness as possible to give a more efficient flow of air/fuel into the combustion chamber. It took me about 2 hours of fanning about with the dremel and if I'm honest I couldn't really feel any difference although the mpg was slightly better but not by enough to make me want to do it again.

Col
 
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Polishing the ports on its own probably won't gain you very much at all.
It's the sort of procedure which would need a number of other jobs too such as inlet manifold polishing, joint/gasket matching to prevent or at least reduce airflow disturbance and vortexes where the manifold meets the cylinder head. You should also consider polishing the cylinder head and balancing the cylinders.
If you're going to do all that lot, I wouldn't even consider it on a production line built diesel engine if I were you. There's a reason why hand-built engines cost so much.
 
It is a lot of work for potentially little gains. Turners do a ported TD5 head and claim 30% more power/torque and better mpg to me that seems a tad embellished...

I have been offered a head so could do the inlet, exhaust and head if I **** it for any reason it's only a spare! Though I was under the impression polishing isnt the best as the reduces turbulence and thus actually hinders the fuel/air mix where as a rougher surface excites the air/fuel particles causing them to mix more efficiently.
 
brian47 said:
Polishing the ports on its own probably won't gain you very much at all.
It's the sort of procedure which would need a number of other jobs too such as inlet manifold polishing, joint/gasket matching to prevent or at least reduce airflow disturbance and vortexes where the manifold meets the cylinder head. You should also consider polishing the cylinder head and balancing the cylinders.
If you're going to do all that lot, I wouldn't even consider it on a production line built diesel engine if I were you. There's a reason why hand-built engines cost so much.
Click to expand...
Agreed. I've known a few petrol head diy mechanics spend a lot of time and money tuning the head, re-profiled cams, custome exhaust manifold etc etc but didn't do anything to improve the bottom end. It nearly always ended up in total engine failure. A friend of mine put a heavily modified engine from a rally prepped mini into his old mini 850 but didn't bother to upgrade the suspension, brakes or steering. He crashed it on his first outing.

Col
 
Jesus! Not the best thing!

I wouldn't go as fasr as re-profiled cams and such, though maybe have it balanced while in bits but at the end of the day it currently runs well!

Maybe if the HG ever goes I'll do it, though kinda laos want something to do haha
 
If you do it, let us know how you got on and your method. My old series 3 is still running with its original head which hasn't been converted to run on unleaded petrol. Also the valve stem seals are knackered and I keep thinking about getting a Turner head, their tuned head isn't that much more expensive than the standard so I'd probably get one of them. I'm waiting for a good enough excuse to get the head off to do the change but I'm not as fit as I was and lifting the bugger off is going to be a struggle unless I acquire an engine hoist thingy.

Col
 
Yeah I'll do some more research and see but from what I've found so far there are only a handful of people that have done it to a TD5 and as I said in the OP most are old dead threads, one is recent though so following.
 
Hi bankz5152 I asked the same question on LR4x4 forum a while ago for my 200tdi as I got a spare head off eBay ,some were for doing it and others were you won't get a lot of power gain for the outlay don't know if you've read that one can't post the link cus I'm on the iPad and I don't know how to do it :rolleyes: . The jist I got was it improved drivability and added a bit more power , was planning to get it done but by a pro as people who had tried there selves had had mixed results if I remember right the exhausts are polished and intakes rough and then you match the port size to the gasket was still planning to have it done or might still have a go myself but not at the top of my list at the moment.
Cheers Ian
 
Yeah that makes sense, if the exhausts are polished then it reflects the heat back in and out quicker!

I havnt read it but ill have a search! Same username?
 
Colthebrummie said:
Agreed. I've known a few petrol head diy mechanics spend a lot of time and money tuning the head, re-profiled cams, custome exhaust manifold etc etc but didn't do anything to improve the bottom end. It nearly always ended up in total engine failure. A friend of mine put a heavily modified engine from a rally prepped mini into his old mini 850 but didn't bother to upgrade the suspension, brakes or steering. He crashed it on his first outing.

Col
Click to expand...

Yeah, I remember a young un many years back, he had a MkII Cortina and was dead chuffed with his efforts to make it go faster, so I asked him what he'd done to the brakes. He looked at me stupid.
The Cortina didn't last long.

Even my father told me when I first started driving that you never make a car go faster until you can make it stop quicker.
 
brian47 said:
Yeah, I remember a young un many years back, he had a MkII Cortina and was dead chuffed with his efforts to make it go faster, so I asked him what he'd done to the brakes. He looked at me stupid.
The Cortina didn't last long.

Even my father told me when I first started driving that you never make a car go faster until you can make it stop quicker.
Click to expand...

Very true but end of the day its a Defender! It's never going to be a race car haha i'm certainly not going to be ragging it round corners and the like! It does stop quite well, planning on new callipers & some EBC slotted discs (coz theyl ook nice :p) soon More of wondering if its worth doing and if it can be done at home. IF what folk state is true may be worth it!
 
Good read! (link if anyone wants a look)

Seems very mixed! Only really worth doing if you can do it yourself, with a spare head kinda thing, though doesn't look like it's too hard if you stick to a modest port and don't go over board. Looks like it could be done to a TD5 for less than £300 (head, gasket, bolts n bits)

This makes for a good read too

So -
Gasket match inlets and leave rough
Gasket match exhaust and polish
Clean and polish valves and seats

Doesnt seem like tooo much work!
 
Last edited:
brian47 said:
Yeah, I remember a young un many years back, he had a MkII Cortina and was dead chuffed with his efforts to make it go faster, so I asked him what he'd done to the brakes. He looked at me stupid.
The Cortina didn't last long.

Even my father told me when I first started driving that you never make a car go faster until you can make it stop quicker.
Click to expand...
Its the old story, we couldn't fix the brakes, so we made the horn louder
 
Porting, the major gains are made in the following places.

Steps between manifold and heads, if inlet manifold larger than port, enlarge port to match.

Tidying obstructions, strange casting anomolies, that sort of thing, smooth them off.

No need to poilish intake.
 
Glad you enjoyed the read bankz5152 that guide on how to is very good still would like a go myself , but on that 200tdi head I've got there were some ripples in the cast inside were the valve sits and not sure if it's safe to smooth them out or not .
 
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