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MG MGF Technical - FAO Rob Bell: VVC/TF heads

Rob, your wonderful website says that the TF head had machineing on parts of it that were like a poor mans porting and which improved breathing over the old F head. Roy at Techspeed said he didnt think the heads were any different and that the improved power came from a better TB, exhaust and ecu remap. He's had some TF heads off and looked! Did the head that you and Dave (?) looked at come from a pre production TF or maybe a Trophy?
m hanson

Both Rob and Dave are at Bedford Trackday today..(and so would I if my car wasn't in bits :-( ) So don't expect a reply until later or even tomorrow

Stu
Stu Dickens

Here's your answer (thanks to Rob):

The machined ring around the exhaust valve will give increased airflow on low valve lift.

http://mgf.ultimatemg.com/group2/engines/images/cylinderhead_145v160_w250.JPG

Sander

Thanks Sander. Marc, this head was from a production TF. The TB, improved breathing and remapped ECU (MEMS3) all help, but the improved breathing at low-valve lift is reckoned to be the single greatest contributor.

By this token, relieving your 145 VVC head in a similar fashion ought to go a long way towards releasing 160 horses... Dave and Stu, with fully ported VVC heads (and retaining the VVC mechanisms) see close to 180bhp.
Rob Bell

Sander

The 160 head shown has significantly bigger inlet valves (2mm as best as I can scale of the screen). What size are they in real life?
Wouldn't that have ever so slight an effect?
Paul Walbran

Paul, no, the TF160 uses exactly the same size of valve as the earlier versions of the VVC. Any apparent size difference is I suspect a visual illusion.
Rob Bell

Rob

That's my experience of TF160 heads I've seen, but have a closer look at that pic - the "160" valves are much closer together, and if you measur them on screen they are also bigger, whereas the exhaust valves in each case are about the same.
Paul Walbran

It could also be that it's time for me to get shut-eye!
Cheers
Paul Walbran

Thanks all. Rob, to stay in standard class I cant port the head but can swap my F head for a TF head. Presumably its a straight swap? As to the ECU, is it a big job to change to the MEMS3 from the old 96 F ecu? Would I need to do that anyway if changing the head? I suppose if it all stacks up I can just get the current head ported and run in RGM class but I fear itd encourage me to take the car to bits and turn it into a full on racer. Id need another mortgage!
marc h

LOL Paul! Well, I can definitely tell you the valves are the standard size - I was the photographer :o) I suspect that what you are looking at as valve area is the machined area around the valve seats that increases the area of the 'pocket' around the valve that improves air flow?

Marc, TF160 head is a straight swap to an eariler VVC. And don't bother with MEMS3. Keep with MEMS2J; you have larger injectors on your engine than are fitted to later 160 engines (size reduced so as to make the engine easier to map to pass EU3 emissions targets). Large injectors and MEMS3 I suspect will not mix well for rather obvious reasons! ;o) Besides, you won't be permitted to tamper with your ECU for sprint regulations.

HTH
Rob Bell

Thanks Rob. Time for a chat with Summit Motorsport I think. Techspeed don't want my money anymore (and Ive never been difficult and spent Ive spent thousands)They have bigger fish to fry. B&G were asked for a quote for a fair bit of work and didnt come back to me. I hear the boys at Sumnmit are good and have expierience of racing Fs
marc h

I've not heard of Summit? Let me know how you get on with them. Where are they based?
Rob Bell


"Techspeed don't want my money anymore"

I think it's probably the race season that makes it a bit difficult for Techspeed Marc, Outside this they have alot more time. My cars in there now awaiting a new hybrid gearbox, It's going to take a few weeks but I am prepared to wait for their expertise.

Stu
Stu Dickens

Stu, I was in discussions with Roy earlier this year (before the race season) about a lot of work that I wanted doing to my car. We spent some time finalising the scope and then I was told that due to the demands of the race teams they look after they werent doing anymore private cars. Pretty disappointing as it was too late to get anyone else to do the work for this season. Funnily enough Roy's just called me about my post above. Saying they had "bigger fish to fry" was a bit strong but you can see my point. Anyway, the reason was they turned my work (and some others) away is that they have been very busy this year due to having one man down and a number of teams to service. They should be quieter in the autumn after the end of the season (October 17th?)when they can take on more "private" cars.

Rob, Summit are in Maidenhead. They run a couple of ZRs / Fs in various race series. They have also done some work on a couple of cars in the Championship and come highly recommened.
marc h

That's a relief - and my car will need servicing in October! I knew my service due date was at the tail end of the year for good reason ;o) LOL
Rob Bell

This thread was discussed between 19/07/2006 and 24/07/2006

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