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Discussion Starter · #1 ·
Just had an e-mail back from janspeed regarding the re-working of the head on my 160.

£529.......to re-work a supplied head
£899.......to remove, re-work and re-fit

Copy of mail below:-

We would recommend a straight forward re-working of the head, which on the earlier VVC models (145bhp std) but fitted with the same mods asyours were running 170-175bhp. We haven't tried this on the later 156bhp models yet but you would expect to see a similar incremental gain, so around 180-185bhp.
For us to carry out the work here, including the labour to remove and
refit the cylinder head would cost £899 inc VAT. If we just work the
cylinder head you supply, the cost will be £529 inc VAT.


This doesn't take into account mine has been chipped too ;)

If anyone has obtained a better price for a similar increase, i would be very interested :mrgreen: :mrgreen:
 

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I believe the likes of Dave Andrews found that porting the 145bhp head and the 160bhp head brought them both up to around the same total bhp. Not 25-30bhp for both heads but only 15bhp for the 160 head.

And this is with exhaust / intake mods already in place.
 
G

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Have a look at the Mike Satur site.

Just out of curiosity, how much extra does this hike your insurance, all the mods you have done to increase trhe power?
 

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Discussion Starter · #8 ·
Light Sabre said:
Have a look at the Mike Satur site.

Just out of curiosity, how much extra does this hike your insurance, all the mods you have done to increase trhe power?
With what i have done so far, i pay£50 extra..........but its worth it as ALL my mods are declared. This head work would hike it by a further £40.
 

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AndyK160 said:
Light Sabre said:
Have a look at the Mike Satur site.

Just out of curiosity, how much extra does this hike your insurance, all the mods you have done to increase trhe power?
With what i have done so far, i pay£50 extra..........but its worth it as ALL my mods are declared. This head work would hike it by a further £40.
thats sounds bloody good to me young man !!!!!!
well worth the investment ;) ;) ;) :up: :up: :up: :up:
 

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Discussion Starter · #10 ·
yellow-peril said:
AndyK160 said:
Light Sabre said:
Have a look at the Mike Satur site.

Just out of curiosity, how much extra does this hike your insurance, all the mods you have done to increase trhe power?
With what i have done so far, i pay£50 extra..........but its worth it as ALL my mods are declared. This head work would hike it by a further £40.
thats sounds bloody good to me young man !!!!!!
well worth the investment ;) ;) ;) :up: :up: :up: :up:
Lmao Stewart, not been called young man for years.........i thank you, especially as you are younger than me.........lol.

But it is something i am seriously considering in the new year ;)
 

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wow! 180bhp!!! nice! but expensive.

(what are janspeed make on the cylinder head? I dont understand it very much because I'm swiss)
 
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Robmaster said:
What makes Janspeed exact at the cylinder head? :ban:

I am very much interested in it. :bash:
"Janspeed" are an engineering company based in the UK who specialise in exhausts and engine tuning

http://www.janspeed.com/

Have a look at thier web site which might go a little more towards explaining who they are and what they can do.

Hope that helps?
 
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AndyK160 said:
Light Sabre said:
Have a look at the Mike Satur site.

Just out of curiosity, how much extra does this hike your insurance, all the mods you have done to increase trhe power?
With what i have done so far, i pay£50 extra..........but its worth it as ALL my mods are declared. This head work would hike it by a further £40.
"'kin 'ell"!

Thats bloody good. Who is that with as I need to change my insurance company as I am getting ripped off!
 
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The main thing is to also open the inlet and exhaust manifolds to the same diameters and also make sure that the mating faces line up as do the ports. The interior surfaces can be polished to aid airflow. The whole lot is then put on a bench and the flows through each of the parts of the head are measured to make sure that it is all the same. If you dont then you could end up with one cylinder getting a bigger air/fuel charge than another and power distribution throughout the engine will be unbalanced.
 

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A pal advised that there was interest in this area and since I fitted what was the original development VVC head from Janspeed to a R200 BRM back in mid 1999, and others since, my experience may be of interest.

The bottom line is that the VVC head, irrespective of 143 or 158 specs is essentially the same as far as modification is concerned. Minor differences between the two standard specs are 'overwritten' when the head is modified.

The other point is that the breathing capacity of the head is related to valve lift and whilst there are gains to be had in the lower lift areas, the big gains seen with developments like Judd's K2000 need cams that can exploit this. It's all very well seeing 40% or whatever increases in flow at 11mm and above valve lifts, but a complete waste of time and effort if the cam only lifts to the standard 9.5mm!

So for general road use where the cam lift remains standard there isn't the big window for large gains in terms of top end power. I would concur that the Janspeed claims are real world expectations for most engines in fine fettle, with some engines able to give an extra bonus on top.

What I regard as the biggest gain from fitting the head to the BRM was in mid range torque that not onlu completely filled the dip in the standard torque curve that affects the 3000 to 4500 rpm area, but the way in which it noticeably enhanced torque from just above idle. Being as it is torque that provides acceleration this is more important and indeed most effective. The same sort of pull seen on standard engines between 5000 and 7000rpm is now experienced from 3000rpm is perhaps the best way to describe the changes, plus there is a bonus with the upper rpm ranges being sharper too.

The VVC head is a factory perforomance K series head where the shortcomings of the MPi head have been addressed within the designed lift range of the cams. It flows significantly better than an MPi head which is why it is so widely sought after for fitting to Mpi engines with the solid cam conversions. It does however have common production line compromises that reduce flow and efficiency. primarily these can be seen in the manner of the fit of the valve seat inserts and the dreadful, for flow, steps between the seats and the ports. Then there are often casting irregularities in the ports so that addressing these provides a worthwile improvement to flow. Add to this three angle cuts to the seats and carefully blend or back cut the valves and you add to the smoothing effect that increases flow, especially at lower valve lifts. This work is relatively simple and not so time consuming that it makes for an over expensive product and why it is offered. Another benefit of this work is that by evening out the flow in each port the resulting flow into each cylinder is evened out and so firing pulses are more even. This has a marked effect on the smoothness of the engine and on an old MGF I had I achieved the mid 150's in terms of peak power for relatyively few changes, but I did have to change the standard exhaust as I could neither hear or feel the engine when idling in traffic and that makes for less easy stop start driving. Remember also that extra flow doesn't guarantee extra power, but that without flow you can't have power!

The target on the BRM was to achieve 100bhp per litre whilst retaining the standard single throttle plenum system and management system. The engine was ceratinly close enough in all testing from different rolling road results to legitimately believe this, although numbers on their own are irrelevant, it's how the car drives thats important. Numbers come into their own for comparisons of like for like tests, from the same equipment for development and checking purposes.

The spec of the BRM stopped short of all modifications that could have been easily done and ended up with the head (using standard valves and VVC mechanism), standard alloy inlet but with a 52mm throttle body, ITG Maxogen filter system for the 200/25/ZR and a cat back Janspeed exhaust. The rest of the engine was standard although I welded the exhaust manifold on the outside between pipes and flanges and ground out the inner welds. This was worth a whole zero in extra power, but at full tilt on the rollers the exhaust manifold clearly ran cooler.

I have done various additional testing and it is interesting to see repeated back to back tests between 48 and 52mm throttles show that in power terms the 52mm body showed no power difference below 5000rpm and from there to 7000rpm it progressively increased to peak at an extra (flywheel) 5bhp. Interesting to note that the 55mm throttle found on the earlier MEMS1.6 MPi K series (1993 to 1995) and all T16 engines did not show any advantages over the 52mm throttle. These figures do seem to conflict with the sharper feeling you get at all rpms with the 52mm throttle, but have since been done on other engines and confirmed!

Also of considerable interest is the BRM was never fitted with a Janspeed exhaust manifold. The standard manifold is, after the standard air filter, one of the most restrictive engine parts and so shows big gains. The manifold change on other engines has been worth between 6 and 9 (wheel) bhp, but again it is one of those mods that helps torque too so it is readily felt in terms of performance increase. It would have been interesting to see what the manifold made on this modified engine.

The exhaust manifold may not have been changed but I did some back to back testing of the Maxogen for the 200/25/ZR, as fitted to the BRM, against a standard (143bhp spec) filter and the larger Maxogen filter used on MGF, TF and ZS180. (The latter an item I developed with ITG on my old ZS180 and hence my preference to ITG.)

The standard 143bhp spec filter is not noted for it's flow ability. In testing and up to 3000rpm there was no recorded difference between it and the dedicate ZR Maxogen, but standard power was 5% less at 4000rpm, 10% down at 5000rpm, 18% down at 6000rpm and 16% less at 7000rpm. (Rounded to nearest number) Incidentally make sure the moulded intake is always in place for the ZR Maxogen as power suffers badly if it is removed, especially on warm days.

The ZR Maxogen is certainly effective and was developed to fit available space, but as a matter of interest I surmised that the space restriction compromised ultimate efficiency. The larger Maxogen was connected to the throttle body using the same hose and the cold air pipe was routed to the same area leaving the body laid on top of the original filter space. There being no prospect of shutting the bonnet, but non ABS cars may have more scope, especially since I have also successfully fitted this filter to Rover 100 with 16v K series.

The bottom line with this comparison is that there was no difference until above 5000rpm, and at 6000rpm the larger filter was 23% better than the original standard Rover filter (and 5% more than the smaller ITG.) The at 7000rpm it was 21% better than standard, (4% better than the smaller ITG). I mention this to illustrate that there remains some scope for further improvements in air filter, but that it will only be seen at the higher rpms.

Other tweaks include measuring and adjusting fuel pressure. Nominally MEMS MPi systems operate with 3bar fuel pressure, but the reality is that mechanical variation is expected, so a standard regulator is deemed serviceable where the working pressure is seen between 2.8 and 3.2 bar. Of the significant number of regulators I have tested they are usually close to 3 bar, but age does see a tailing off of working pressure. As an alternative to an FSE or similar, the BRM was fitted with a modified standard regulator which had been squeezed in a jig so that the internal spring pressure was increased so that it was reset to work at 3.2bar. This is within the sandard range so lambda control is not lost, but ensures that at full load fuel flow volume is maintained, with a small potential bonus. In fact going to 3.3bar has been tried and remains compatible.

Certainly testing airfuel ratios at full load on the BRM confirmed no leaning. so standard mapping, injector flow and fuel pressure were fine. At the other end lambda control was still spot on. Needless to say this mod showed no power difference, but then it was done as reliability insurance not a power mod.

I have been impressed with K series every since driving a development hack Montego in 1988 fitted with a 1400 16v development K series that felt as fast as a 2.0 litre MG Montego. I have done many things since with the K, but always relatively mild as the engines were to be hauling relatively heavy steel bodied cars, not half ton fibreglass bath tubs, so torque is more important than top end power.

I have done heavily modified MPi heads with metal welded to ports for provide the height needed to replicate the 3mm higher port line of the VVC/Motorsport heads, used different valves and ended up with very effective torquey and smooth engines. I currently have another VVC head casting and matched alloy inlet, modified by my long time friend Pete Burgess, which will be assembled over the holiday with a Piper 270 solid cam for use on my sons 1.8 R100.

Early 2005 sees some stepped and progressive testing of another VVC car with the new Emerald VVC ECU with various bolt on mods inc multiple throttle bodies to see what can be achieved with just external changes. Projections for both developments are modest in hoping to break through the 100bhp per litre mark with improved driveability, yet this includes the retention of standard reliability and for normal driving conditions similar fuel economy.

I am happy to speak with anyone and pass on my experiences. Remember what I have seen is only applicable to the engines and cars I have been using and so only provides a guide to what similar mods on another engine/car will deliver. Remember each engine is an individual and like humans can be athletic or asthmatic, grumpy or happy and this always has an effect on what is achieved.

Best mail to get me is [email protected] as my time for BBS visits is very narrow.

Rog
 
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