free hit
counters
2GR Engine Build - Engine & Ancillaries/Gearbox - The Lotus Forums Jump to content


Recommended Posts

As some may be aware from my build thread, I have now had the charge cooled TVS1900 supercharger fitted by Komotec and am very happy with the results, although I am still working with Komotec and Back on Track to iron out some issues with the mapping that remain at part throttle/low speed.  As a brief summary, my car is now running the following engine spec: 

•             Charge cooled TVS1900 supercharger

•             Large 76mm throttle body

•             550cc fuel injectors

•             Komotec EX500 extra large carbon air intake

•             2bular exhaust headers/down pipe/sports cat/silencer (Zircotec performance white coated)

•             Moroso Baffled Sump

•             ECU Master EMU Black with dual maps.

On the “Road” map it is producing around 400hp, and on the “Track” map it is up to 493hp and around 530NM, calculated at the crank from the dyno at Komotec. 

The engine is now producing plenty of power, and bags of torque, which is great.  However the redline remains set at 7200 rpm and I really would like to raise this to make the engine really come alive more.  I am aware of guys over in the US (mainly people who have dropped the 2GR engine into Toyota MR2s) who are able to spin the engine to 8000 rpm or even up to 8500 rpm. 

Clearly that is going to require some fairly significant internal engine work.  The obvious stuff is rods, pistons, cams, bearings and bolts.  I would also imagine that some fairly serious work would need to be done on the valvetrain.  For example, I understand that there are issues with the standard hydraulic lifters on the 2GR engine when spinning at high rpm.  Monkeywrench Racing (who are building a lot of the high spec 2GR engines in the US) have some interesting looking products for the valvetrain: 

https://www.monkeywrenchracing.com/product/mwr-valve-set-24-2gr-fe-titanium-standard-size/

https://www.monkeywrenchracing.com/product/mwr-valve-spring-retainer-set-2gr-fe-2gr-fse-titanium/

https://www.monkeywrenchracing.com/product/mwr-valve-spring-set-24-2gr-fe/

https://www.monkeywrenchracing.com/product/mwr-valve-stem-seals-kit-toyotalotus-2gr-fe-v6/

They also have some pretty aggressive camshafts (although these are just reground cams rather than fully new machined):

https://www.monkeywrenchracing.com/product/mwr-cam-set-4-2gr-fe-v6-stage-2/

https://www.monkeywrenchracing.com/product/mwr-cam-set-4-2gr-fe-v6-stage-3/ 

I am not really looking for significantly more power or torque, although I would expect a slight bump in headline numbers as a consequence of doing the build.  What I am really after is giving the engine more “zing” and allowing it to really spin hard to around 8000 rpm or even a little higher.  But of course, it must be robust and totally reliable.

Has anyone considered or carried out any of these kinds of modifications themselves?  Does anyone have any recommendations for experienced engine builders in the UK that would be well qualified to take on this kind of project?

Thanks!

  • Like 2
Link to post
Share on other sites

Upgrade today to remove Google ads and support TLF.
  • Replies 7
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

As some may be aware from my build thread, I have now had the charge cooled TVS1900 supercharger fitted by Komotec and am very happy with the results, although I am still working with Komotec and Back

You can alos check with Track Group who builds the Cosworth spec GLA/GLB engines. However, I understand it as they change to solid lash adjusters - which is fine until until you need to adjust the val

Caution going with Ti valves...  They don't do very well in day to day cars and do wear quite aggressively.  We treat a lot of them in the states for LS7 motors with DCT and WPC as well.  

Have you contacted Swindon Powertrain Ltd. I think they build some N/A V6 engines for the Evora race cars that made 400bhp or so. There were some crate engines knocking about a few years ago.

And have Cosworth done some work on this engine too?

Link to post
Share on other sites

You can alos check with Track Group who builds the Cosworth spec GLA/GLB engines. However, I understand it as they change to solid lash adjusters - which is fine until until you need to adjust the valve clearance and have the TVS1900 covering one cylinderbank :(

What I find interesting is that MWR claims their 50 % stiffer springs to be good for 7700 rpm and that you would need Ti valves and solid lash adjusters to run safely at 8000 rpm. Jubu Performance, on the other side, offers 30 % stiffer springs which they claim are good up to 8000 rpm, even with 13,5 mm lift. It is not easy to be a consumer..

In any case, I am considering the same operation, so if you can get some 1st hand information and share it, it would be great!

  • Like 1
Link to post
Share on other sites

Thanks @#84. I am already in touch with Track Group as I previously spoke to them about the project last year. Will certainly be happy to share details with you.

I am keen to avoid switching to solid lifters if I can avoid it. Too much hassle for ongoing maintenance as you say. My preference would be to use stiffer springs, lighter valves, and a can with just enough lift and duration to do the job but no more.

I don’t believe that the Cosworth engines use solid lifters, but they also redline at 7,600rpm...

Link to post
Share on other sites

Caution going with Ti valves...  They don't do very well in day to day cars and do wear quite aggressively.  We treat a lot of them in the states for LS7 motors with DCT and WPC as well.  

  • Like 1

If the only thing constant is change, then why do we resist change the most?

Link to post
Share on other sites
18 hours ago, Mattmahope said:

That’s interesting, as you would expect Ti valves to be fairly strong. I guess the Issue is probably rubbing on the steel valve springs or lifters?

They are strong but you must buy them coated as they can gall.  chromium nitride (CrN) is a good coating ....and make sure your guides are copper bronze.  Titanium suffers from very hot flame temps over time as well as elongation of the stem.  There is much more maintenance when you use Ti valves to make sure you don't drop one "unexpectedly".  

  • Like 1

If the only thing constant is change, then why do we resist change the most?

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.




×
×
  • Create New...