G40R 2.5 litre Duratec
Discussion
Remembering back to the beginning of this saga, I looked at the invoice from Guglielmi Motorsport to see how many hours they charged me for the original engine swap. I did help out a bit with running around collecting parts for them to fit. Nevertheless, it was amazing how quickly and efficiently they did that job compared to the many hours of head scratching, trial and error etc that I used up finishing off all these details. So I can again recommend Guglielmi if you are in the Northants area. They are in Daventry.
Looking at the engine invoice from Raceline, most of the cost was the parts. The amount I could have saved in labour and machining by taking a DIY route was not worth all the personal time, trouble and research effort I would need to make. Plus I would have to farm out any machining and hope it was done correctly. Not worth it. The knowledge and support that came from Raceline as part of the engine package was invaluable. They are now working on some 48mm throttles for me, so more is still to come.
Looking at the engine invoice from Raceline, most of the cost was the parts. The amount I could have saved in labour and machining by taking a DIY route was not worth all the personal time, trouble and research effort I would need to make. Plus I would have to farm out any machining and hope it was done correctly. Not worth it. The knowledge and support that came from Raceline as part of the engine package was invaluable. They are now working on some 48mm throttles for me, so more is still to come.
In preparation for getting a new exhaust fitted, I decided to take a look at the metal tunnel sections running in the gap between the lower chassis rail and the body sill either side of the car. Also, a lot of road dirt and stones was flying forwards off the rear wheels and collecting on top of these tunnels, due to open inner rear arches. I wanted to clear the muck out and then fabricate some closure plates for the inner arches.
The tunnel sections for my car were secured unbelievably with zinc plated M6 button head screws, totally unsuitable for the harsh environment underneath a car. 5 screws each side fix the tunnels to the body sill. 6 screws each side fix them to the chassis. My car had done only 3000 miles, mostly dry and always garaged. However, the screws were factory fitted dry, with no assembly lube. The heads have only a shallow 4mm hexagon socket. It’s a guaranteed mess of seized in screws. After a good dose of penetrating oil, patience and persistence, all 10 of the sill screws came out. Of the 12 total into the chassis, only 4 could be carefully unscrewed. Remaining were 8 screws where the hexagon sockets just rounded out. No amount of hammering, chiselling would get these things to budge. Then it’s a case of welding nuts on to the button heads and trying to spanner them off, easing back & forth with doses of penetrating oil. That got another 6 out, though in some cases they initially sheared off and needed a new nut welding on to the screw stub. The welding heat also probably helps release the rust.
Finally, there were 2 screws with the heads sheared off and completely stuck in the chassis, both at the right rear where the exhaust pipe hangs on. I resorted to drilling though the fibreglass sill and through the screws with extra long drills, going 3, 4, 5mm in steps. The screws are tough, so had to keep re-sharpening the drills. Managed it in the end and cleaned up the tapped holes. All screws replaced by stainless and used hexagon heads in the chassis with lots of anti-seize. What a complete avoidable mess!!
The tunnel sections for my car were secured unbelievably with zinc plated M6 button head screws, totally unsuitable for the harsh environment underneath a car. 5 screws each side fix the tunnels to the body sill. 6 screws each side fix them to the chassis. My car had done only 3000 miles, mostly dry and always garaged. However, the screws were factory fitted dry, with no assembly lube. The heads have only a shallow 4mm hexagon socket. It’s a guaranteed mess of seized in screws. After a good dose of penetrating oil, patience and persistence, all 10 of the sill screws came out. Of the 12 total into the chassis, only 4 could be carefully unscrewed. Remaining were 8 screws where the hexagon sockets just rounded out. No amount of hammering, chiselling would get these things to budge. Then it’s a case of welding nuts on to the button heads and trying to spanner them off, easing back & forth with doses of penetrating oil. That got another 6 out, though in some cases they initially sheared off and needed a new nut welding on to the screw stub. The welding heat also probably helps release the rust.
Finally, there were 2 screws with the heads sheared off and completely stuck in the chassis, both at the right rear where the exhaust pipe hangs on. I resorted to drilling though the fibreglass sill and through the screws with extra long drills, going 3, 4, 5mm in steps. The screws are tough, so had to keep re-sharpening the drills. Managed it in the end and cleaned up the tapped holes. All screws replaced by stainless and used hexagon heads in the chassis with lots of anti-seize. What a complete avoidable mess!!
In true TVR fashion, the powder coating was flaking off too, so some time was needed to de-rust and epoxy paint these areas. This will no doubt be a continuous process, like painting the Forth Bridge!
To stop road dirt being thrown forwards into the sill void, I made some plastic closure panels which fit in front of the rear wheels, at the bottom of the inner wheel arch. This one is from the left (non-exhaust) side.
To stop road dirt being thrown forwards into the sill void, I made some plastic closure panels which fit in front of the rear wheels, at the bottom of the inner wheel arch. This one is from the left (non-exhaust) side.
At last, some more updates, this time on the exhaust catalyst and trying to pass the MOT emissions. The original factory Cat always passed with the original 2 litre engine, but the 2.5 was reading high on CO, no matter what. This was strange, as hydrocarbon emissions were minimal and the lambda was good and stable.
I found it really hard to reach anyone who could give definitive answers how to proceed, whether that be engine people, exhaust specialists or rolling roads. Duratec engines are also commonly used in the Caterham world, but there is effectively infinite space available to mount a Cat with the external exhaust arrangement of a Caterham. This compares to the G40 where there is very limited space to jam in the Cat behind the front wheel. Overall, this is an area of poor design in the G40. A few more inches of wheelbase would have allowed more room to package a decent exhaust.
Could only conclude that the original Ginetta Cat, rusty and scabby looking, perhaps had its day.
I found it really hard to reach anyone who could give definitive answers how to proceed, whether that be engine people, exhaust specialists or rolling roads. Duratec engines are also commonly used in the Caterham world, but there is effectively infinite space available to mount a Cat with the external exhaust arrangement of a Caterham. This compares to the G40 where there is very limited space to jam in the Cat behind the front wheel. Overall, this is an area of poor design in the G40. A few more inches of wheelbase would have allowed more room to package a decent exhaust.
Could only conclude that the original Ginetta Cat, rusty and scabby looking, perhaps had its day.
Next up was to try and get a new Cat pipe made. Local suppliers were booked up and somewhat equivocal anyway towards my emissions questions. Eventually I tried a custom exhaust supplier located in the northwest, who I used many years ago when living in that area. Previously, they ran a combined workshop and exhaust fitting business, with a lot of practical experience and timely service. Fast forwards 20 years or so and they had moved to a neighbouring town with more of a large scale factory operation and longer lead times. Oh well, I decided to give them a try.
The result was a new Cat pipe, plus a De-cat pipe for track use.
The result was a new Cat pipe, plus a De-cat pipe for track use.
Sadly, the emissions were no better than the old Ginetta Cat. Additionally, I had an unpleasant encounter with a very unfriendly MOT man who spent most of his efforts ranting and telling me off. How he came to be recommended to me by the local motorsports shop I will never know.
It turned out that the new Cat pipe was a Euro 3 standard Cat, which the northwest exhaust factory had somehow not realised was below spec for a 2014 car. Like I said, hard to find people who really know what the score is.
So if you want a job doing properly, sadly you often times have to do it yourself. A call to Jetex Exhausts yielded a Euro 5 Cat which they were able to supply as the mantle (core) only with a range of cones and adapters for me to try and make something fit into the cramped space. Neil at Jetex was a very helpful guy and gave good advice - thanks!
I also found a few other useful bits and pieces at Exhaust Parts UK.
The result was the Frankenstein Twin Cat, combining the new Jetex Euro 5 Cat running horizontally direct off the manifold with the previous Euro 3 Cat bottom section. After all, I had paid for the E3 Cat and it wasn't like I was ever going to get my money back for it, so may as well use it.
Sorry for my rough welding, but it does all hold together with no leaks. The inlet cone to the E5 Cat is intentionally offset, to keep the Cat away from the bodywork.
It turned out that the new Cat pipe was a Euro 3 standard Cat, which the northwest exhaust factory had somehow not realised was below spec for a 2014 car. Like I said, hard to find people who really know what the score is.
So if you want a job doing properly, sadly you often times have to do it yourself. A call to Jetex Exhausts yielded a Euro 5 Cat which they were able to supply as the mantle (core) only with a range of cones and adapters for me to try and make something fit into the cramped space. Neil at Jetex was a very helpful guy and gave good advice - thanks!
I also found a few other useful bits and pieces at Exhaust Parts UK.
The result was the Frankenstein Twin Cat, combining the new Jetex Euro 5 Cat running horizontally direct off the manifold with the previous Euro 3 Cat bottom section. After all, I had paid for the E3 Cat and it wasn't like I was ever going to get my money back for it, so may as well use it.
Sorry for my rough welding, but it does all hold together with no leaks. The inlet cone to the E5 Cat is intentionally offset, to keep the Cat away from the bodywork.
Hi Podie. The MOT place in question is just around the corner from where Steve Guglielmi used to be in Daventry. I had best not identify them more than that on the forum. I only used them because the emissions test machine at my usual test station was on the blink. Anyway, never again!
Yes, the bodywork does get hot, even with some gold self-adhesive heat barrier applied. It's not too bad if the car is moving along, but when sitting idling the side panel behind the front wheel gets so hot you cannot touch it. I might have to tack a shield plate on the outside of the Cat.
Also I have discovered the source of exhaust fumes sometimes entering the cabin. It's coming in at the bottom of the windscreen A post. There is some communication from the inner wheel arch to the A post inside the car. I saw this when the new Cat was burning off some oil/grease residue and smoke was pouring into the cabin like a chimney! I'm in the process of sealing up all the seams which were skipped over in the factory build.
Next rolling road tune will be after I have fitted some 48mm throttles. Then will do Cat and non-Cat runs, but no timetable for that yet.
Also I have discovered the source of exhaust fumes sometimes entering the cabin. It's coming in at the bottom of the windscreen A post. There is some communication from the inner wheel arch to the A post inside the car. I saw this when the new Cat was burning off some oil/grease residue and smoke was pouring into the cabin like a chimney! I'm in the process of sealing up all the seams which were skipped over in the factory build.
Next rolling road tune will be after I have fitted some 48mm throttles. Then will do Cat and non-Cat runs, but no timetable for that yet.
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