C

chipfork

Active Member
I thought I'd post here as this relates to the Synergy and Pierburg MAF that was in my FL1 TD4.

I bought the ron box and pierburg MAF some while back. They've been running for some time with the box switch set for the pierburg MAF, it's been running well and never a warning light. Anyway with other problems the car has been sold off and I salvaged the box and the MAF, however the MAF I've taken out is badged as a Bosch, looks nothing like the pics I've seen of a pierburg. I've found the original pierburg box and sat inside is my original Bosch MAF which has the same part no. on it but does look very slightly different.

I can't see it, but would a pierburg use a Bosch shell? If not and it got swapped around by a garage at some point, then how was it running so well with the ron box switched to the pierburg MAF setting?
 
Nodge68 said:
I think you are onto something there GG ;)
Click to expand...
I am using the Synergy with my original Bosch MAF with the compensation on (Pierburg setting)
It's working fine at the moment, but I do get a puff of black smoke when I plant my foot.
 
Nodge68 said:
I think you are onto something there GG ;)
Click to expand...
for serious issues with melted pistons due to bore wash etc you would not be able to see for the smoke..... I can see no way that the simple synergy maf amplifier could do that - it will simply make smoke if wound up too far. (and it actually ALLOWED it to have such a gain - which I am sure it does not) The difference between the pierburg and the bosch is fairly minor.
 
Joe_H said:
for serious issues with melted pistons due to bore wash etc you would not be able to see for the smoke..... I can see no way that the simple synergy maf amplifier could do that - it will simply make smoke if wound up too far. (and it actually ALLOWED it to have such a gain - which I am sure it does not) The difference between the pierburg and the bosch is fairly minor.
Click to expand...

The piston looked melted, which can happen if to much fuel is added, or that cylinder was extremely lean.
As weather a Synergy could allow sufficient extra fuel and boost to melt pistons, is debatable tbh.
 
Nodge68 said:
JoeThe piston looked melted, which can happen if to much fuel is added, or that cylinder was extremely lean.
As weather a Synergy could allow sufficient extra fuel and boost to melt pistons, is debatable tbh.
Click to expand...
Hi Nodge, I agree it certainly looked melted, and had certainly 'picked up' badly on the bore also. I cannot see any possible way that a synergy MAF amp (even with the added fuel fudge by pressure sensor tricking) could possibly do that in a month of Sundays really mate. It was only one bore as well by the sounds of it. Long before that happened any excessive over-fuelling would just cause it to smoke like a destroyer trying to out-manoeuvre an E-boat lol..:D - I think for that particular 'piston' issue the fault lay somewhere else entirely.
Joe
 
Joe_H said:
Hi Nodge, I agree it certainly looked melted, and had certainly 'picked up' badly on the bore also. I cannot see any possible way that a synergy MAF amp (even with the added fuel fudge by pressure sensor tricking) could possibly do that in a month of Sundays really mate. It was only one bore as well by the sounds of it. Long before that happened any excessive over-fuelling would just cause it to smoke like a destroyer trying to out-manoeuvre an E-boat lol..:D - I think for that particular 'piston' issue the fault lay somewhere else entirely.
Joe
Click to expand...

I agree with you Joe. There's more to it than simply fuelling issues.
I have wondered if the inlet manifold was choked full of goo from the EGR. The TD4 has two inlet manifold runners, one to each valve. If the small upper runner was choked solid, over fuelling in one cylinder could possibly occur.
 
Nodge68 said:
I agree with you Joe. There's more to it than simply fuelling issues.
I have wondered if the inlet manifold was choked full of goo from the EGR. The TD4 has two inlet manifold runners, one to each valve. If the small upper runner was choked solid, over fuelling in one cylinder could possibly occur.
Click to expand...
I like your thinking mate. I have never seen so much crud in an engine than pictures on here of some of the TD4 units with that horrible EGR ! . frightening. !.
I would tend to think that that image was a product of bore 'pick up' and subsequent overheating that caused the issues. If I was to make a best guess, I would also consider the lower bore oil jet spray for that bore as a culprit - mix that with the egr and runner crud - YIKES, as soon as we get 'pick up' it is a rapid down hill spiral of bore scoring, piston expansion, diesel wash and 'Ooooo Feck' the end fell off. :D

Have you ever had or seen a catastrophic rod failure that causes block punch out ? :eek: usually a big-end cap letting go. But - I have seen more than one with piston pick up causing a complete piston lock up followed by a small end failure that then bent or cracked the rod prior to 'escaping'. Even ones where the whole gudgeon pin and part of the piston skirt up to the pin bore has completely parted then let go.. - apparently makes a hell of a noise and requires many changes of underwear...
We used to call it 'A leg out of bed' or a 'Ventilated Crankcase' :D
Never had one on mine but have seen quite a few- my Chevette apparently suffered that fate a year or so after I sold it - it did have a full Bill Blydenstein lump in it though and had been hammered to 'feck' and back :rolleyes:
 
I melted a piston on my Avenger GT with a Tiger kit fitted. That was caused by a slightly blocked main jet in one choke of the front 40 DCOE that was fitted. I didn't really notice it not running quite right but I did used to turn it to 8,000 Rpm on occasion!!
All other pistons were fine but No1 was melted just like that TD4 piston pictured.
I have thrown a few rods over the years. Mostly in Triumph Straight Six engines. They would break off just below the little end, or across the big end bolt land area. I had a rod go on a KV6 too, but it always ran lumpy so suspected it had picked up water at some point. It had 3 bent rods and a very broken one. Unfortunately the crank had also failed so I could never ascertain the exact cause of the failure.
I do know that crank failure of supercharged KV6 will happen at about 250 Bhp. At that power output, the charger is using about 40 Bhp meaning that the KV6 crank can't take 300 Bhp without failure. The pistons and rods are well up to the task though.
 
Nodge68 said:
I melted a piston on my Avenger GT with a Tiger kit fitted. That was caused by a slightly blocked main jet in one choke of the front 40 DCOE that was fitted. I didn't really notice it not running quite right but I did used to turn it to 8,000 Rpm on occasion!!
All other pistons were fine but No1 was melted just like that TD4 piston pictured.
I have thrown a few rods over the years. Mostly in Triumph Straight Six engines. They would break off just below the little end, or across the big end bolt land area. I had a rod go on a KV6 too, but it always ran lumpy so suspected it had picked up water at some point. It had 3 bent rods and a very broken one. Unfortunately the crank had also failed so I could never ascertain the exact cause of the failure.
I do know that crank failure of supercharged KV6 will happen at about 250 Bhp. At that power output, the charger is using about 40 Bhp meaning that the KV6 crank can't take 300 Bhp without failure. The pistons and rods are well up to the task though.
Click to expand...
Ye gads ! :eek: I thought the KV6 was much stronger - Janspeed were getting 300 from the ford V6 - the german 2.9 Cologne unit - in the 80's. !.) Mind you - it is often different driving a load from the front of the crank as opposed to the rear. A SC belt driven from the front of the crank may well overload that area of the crank. I believe most cranks are rated for a certain front shaft load ?. What about turbo charged ? (well, another form of supercharging but not using direct drive lol :) ? is it still limited to around 300 ? - not that that is bad at all - far from it - -
Also, an avenger at 8K - sweet :) .. :)
So many parts - not that long ago were crap (and MOST still are)!!! in the crank rods and pistons area - mostly sintered steel crank and rods and cast pistons. All the good stuff had forged steel rods and crank - and forged pistons. That is a nice thing about our diesels - most of the parts are so massively overbuilt and already would have been classed as 'race spec' not so long ago :D.
I used to love the Cooper 970S (the best of all the mini cooper s models imho!) EN40B forged steel crank from the factory - over-square design, bore / stroke > 1 (about 1.14 if I remember) - with shot peened rods and forged pistons they would rev to over 10K !!! - the Hillman Imp unit also - wow - what a beauty! I used ot love watching them in the 'chairs' at the TT revving to 12K and more - unbelievable really - all based on a fire pump engine from Coventry Climax ..
Need to stop reminiscing :oops: - must be getting old Nodge...
Sorry to OP for OT .....
Joe
 
Joe_H said:
Ye gads ! :eek: I thought the KV6 was much stronger - Janspeed were getting 300 from the ford V6 - the german 2.9 Cologne unit - in the 80's. !.) Mind you - it is often different driving a load from the front of the crank as opposed to the rear. A SC belt driven from the front of the crank may well overload that area of the crank. I believe most cranks are rated for a certain front shaft load ?. What about turbo charged ? (well, another form of supercharging but not using direct drive lol :) ? is it still limited to around 300 ? - not that that is bad at all - far from it - -
Also, an avenger at 8K - sweet :) .. :)
So many parts - not that long ago were crap (and MOST still are)!!! in the crank rods and pistons area - mostly sintered steel crank and rods and cast pistons. All the good stuff had forged steel rods and crank - and forged pistons. That is a nice thing about our diesels - most of the parts are so massively overbuilt and already would have been classed as 'race spec' not so long ago :D.
I used to love the Cooper 970S (the best of all the mini cooper s models imho!) EN40B forged steel crank from the factory - over-square design, bore / stroke > 1 (about 1.14 if I remember) - with shot peened rods and forged pistons they would rev to over 10K !!! - the Hillman Imp unit also - wow - what a beauty! I used ot love watching them in the 'chairs' at the TT revving to 12K and more - unbelievable really - all based on a fire pump engine from Coventry Climax ..
Need to stop reminiscing :oops: - must be getting old Nodge...
Sorry to OP for OT .....
Joe
Click to expand...

The KV6 is "strong enough" for any NA breathing. It's not massively over engineered like some engines however.
Supercharging does cause failure unless power is kept in check. They fail near the front end of the crank. Most likely due to the loads imposed by the charger drive.
Turbocharging is much "softer" on an engine and more efficient too.

My Avenger never made more than 126 Bhp @7600 iirc. I did hang on into the gears to get the best out of it. It has a heavy weight cast crank, well up to the task.
I've never heard of an Avenger or Sunbeam (same engine) break a crank. Or a rod for that matter. I do know that the piston crown can split off sometimes, but that's rare.


Back on topic now
 
Nodge68 said:
The KV6 is "strong enough" for any NA breathing. It's not massively over engineered like some engines however.
Supercharging does cause failure unless power is kept in check. They fail near the front end of the crank. Most likely due to the loads imposed by the charger drive.
Turbocharging is much "softer" on an engine and more efficient too.

My Avenger never made more than 126 Bhp @7600 iirc. I did hang on into the gears to get the best out of it. It has a heavy weight cast crank, well up to the task.
I've never heard of an Avenger or Sunbeam (same engine) break a crank. Or a rod for that matter. I do know that the piston crown can split off sometimes, but that's rare.


Back on topic now
Click to expand...
Sorry :) - last one then defo back on topic - re talbot engines - the 1600 and 2 ltrs lumps - the only issues we had - and it was common - was the crank thrust bearings failing causing quite alarming end float and clutch issues - that was only on fairly highly tune units. We put a tiny chamfered in the main thrust shell bearing to allow more oil to the outside area - later thrust bearings were also better grooved. Otherwise they were bomb proof - especially the 2.0.
 
Joe_H said:
Sorry :) - last one then defo back on topic - re talbot engines - the 1600 and 2 ltrs lumps - the only issues we had - and it was common - was the crank thrust bearings failing causing quite alarming end float and clutch issues - that was only on fairly highly tune units. We put a tiny chamfered in the main thrust shell bearing to allow more oil to the outside area - later thrust bearings were also better grooved. Otherwise they were bomb proof - especially the 2.0.
Click to expand...
So true. One thing I love about that engine is the ease of it to work on. The thrust bearing was a simple steel backed white metal bearing. These could simply be changed when they went loose. It was only ever the front thrust that got worn. Almost definitely caused by the clutch action pushing the crank forward.
One thing that always surprised me was the front pulley. It was just a simple pressing and no damper in sight. Yet it didn't ever suffer crank failure.
On the Triumph engines, if the crank damper is even slightly hard, the crank will break, cracking the block when it goes.
 
Interesting and worrying read, it certainly did fry a piston, no.4 I believe. To note as well I dispensed with the EGR and went for the blanking mod at the same time I fitted the Synergy.
I'm sure when I flicked the MAF setting it prompted an engine warning light once, hence I checked it was set to the Pierburg setting. It 'ran well', it pulled well, felt smooth and there was no smoke.
I'm a little baffled as to why there wasn't a Pierburg MAF in the car, why would a garage want to swap it for a Bosch, I believe they're actually more expensive.
I'm back at home later so will take a pic of the two MAFs I have side by side, there's only a slight difference.
 
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