R8G Turbo - converted back to stock atmo

[cbx6_79]

Hi all
I'm new to the forum, and for the fun of it I thought I could share some pictures from my old R8G Turbo project.
I am from Norway, and since the mid 70's been interested in the R8 Gordini. Have owned a few 1135's and at the early 1980 I thought it would be great to try a turbo conversion.
At that time the prices and availability of cars/parts were very different from today. I had a stock 812 engine and got new 7:1 compression pistons from Venolia in the US. Cylinder head was fitted with larger valves, but camshaft stock atmo.
I bought a set of new Dellorto DHLA, that was designed to allow boost pressure. They fitted directly to the stock inlet manifolds for the Webers. Home made exhaust manifold and a Rotomaster tubo on the top. Wastegate valve was adjusted to 0.8 bar.
The stock radiator was moved to the front of the car, and an intercooler took its original place in the engine compartment. Had the engine dyno tested in Sweeden, and output before any further adjustment was 147 bhp. Stock displacement of 1255 ccm.
Engine was paired with a 353-13 gearbox. The car was actually pretty fun to drive, and I had it as a "daily driver" for a couple of years. Sold it to a mate, but 40 years later I was able to buy it back from him. MOT inspection did not exist at the time I built the car, but now that became an issue.
At first inspection I removed all the Turbo stuff, and installed it back in again after approval. But found out this was a bit too much work to do at every MOT, and now the car is rebuilt to stock engine configuration and wil stay like that. The only thing that is kept from the 80's is the small body modifications.

 

[Adey]

love that! period turbo conversion is awesome. looking forward to updates

 

[Steve Swan]

Was speaking to this Gent on e-mail a couple of weeks back. Bit of a shame it has been put back to Atmo, but I suppose it is worth a lot more that way. Apart from Jody Sheckter's (supercharged) Forced induction car, this must be one of the first Turbocharged 8's ever built. Blow through carbs have never exactly been common. That's why the 5Gordini turbo was a wet turbo, there were no suitable carburettors other than the DHLA from the Lotus.

 

[BobG]

Lovely car! I am currently building a 1.4 turbocharged motor for my R8. See the thread at R8 GT Turbo Too!.

I'm curious as to how you prevented detonation under boost? It's not obvious from your photos.

 

[cbx6_79]

love that! period turbo conversion is awesome. looking forward to updates

Thanks! Opened up the engine last year and was surprised how it looked inside. Cylinders, pistons and bottom end in general was in very nice shape. Valve guides and seats in cylinder head though, was worn. It is now rebuilt with another head, new valves, new pistons and liners, back to stock spesifications. But even though not that much used, I was impressed the engine still worked good after beeing there for 40 years. Adding a pic of the engine compartment as it is today. Very stock apart for the DHLA's still used in stead of the Webers. Gearbox was another story. Bearings on input shaft was totally worn out. Gearbox was NOS when I installed it together with the engine in early 80's.
Brg Jan

 

[cbx6_79]

Was speaking to this Gent on e-mail a couple of weeks back. Bit of a shame it has been put back to Atmo, but I suppose it is worth a lot more that way. Apart from Jody Sheckter's (supercharged) Forced induction car, this must be one of the first Turbocharged 8's ever built. Blow through carbs have never exactly been common. That's why the 5Gordini turbo was a wet turbo, there were no suitable carburettors other than the DHLA from the Lotus.

Thanks again. I would have loved to keep the Turbo, but I considered it too risky now regarding availability and prices for parts. The prices for those Gordini only engine and gearbox parts has sky rocketed. I was shocked now after I bought the car back, how difficult to get, and how expensive parts had become. Not to mention a complete genuine 1135. I remember I bought this car (withot engine and transmission) as a project at the end of the 70's and I payd that time aboth the equivalent 100 GB£. The complete turbo car I sold a couple of years later for about 2000 GB£. It was no risk at that time to do some try and fail, because it was not worth much. That has become another story today. Even though the body has some modifications, the car is a genuine 1135, so I believe it keeps it value better as stock as possible. The MOT inspection issue was also a big contributing factor to rebuild the engine back to stock. It was to much problem over here to get it aproved with the turbo conversion. But as said, a bit of a pity, because it ran well for 40 years, and was very funny to drive!
Brg Jan

 

[cbx6_79]

Lovely car! I am currently building a 1.4 turbocharged motor for my R8. See the thread at R8 GT Turbo Too!.

I'm curious as to how you prevented detonation under boost? It's not obvious from your photos.

Hi. Checked the thread about Your turbo engine build. That is very exciting! At the time I built my engine, it was not that many electronic aids to help you monitoring the engine. I specially order a set of forged Venolia pistons with 7:1 in compession. Then I could boost harder without the risk of detonation. I also installed a "magic" box from Micro Dynamics. That box made it possible to retard the ignition by a certain adjustable amount of degrees, pr 1000 rev increase of engine RPM. I had a pressure switch set to 0,3 bar to start the whole ignition retard procedure. It also had a RPM limiter that was very handy. I sat mine limiter to 7500 RPM. I also had another pressure swith set at 0,1 bar to start the electric fuel pump. When unboosted, the engine ran on the stock mechanical fuel pump (approx 0,3 bar). With boost over 0.1 bar, the electric pump started, and via a pressure regulator kept the fuel pressure 0,3 bar higher than the boost pressure. Because of the presurised carbs, I then avoided fuel starvation at higher boost values. I mostly ran at 0,8 bar, but had the wastegate for a while set to 1,0 bar. Worked like charm . But with a 1255 ccm and 7:1 in compression, it was a vey old school turbo lag engine In addition to the stock Gordini instrumentation, I had a gauge for oil press, oil temp, boost press and fuel pressure.
brg Jan

 

[Steve Swan]

It's funny looking at the original 812 bottom end. How small the mains and caps are compared to the later 810 and every other 13/1400 that followed. Those pistons are not originals though.

 

[BobG]

Thanks again. I would have loved to keep the Turbo, but I considered it too risky now regarding availability and prices for parts. The prices for those Gordini only engine and gearbox parts has sky rocketed. I was shocked now after I bought the car back, how difficult to get, and how expensive parts had become. Not to mention a complete genuine 1135. I remember I bought this car (withot engine and transmission) as a project at the end of the 70's and I payd that time aboth the equivalent 100 GB£. The complete turbo car I sold a couple of years later for about 2000 GB£. It was no risk at that time to do some try and fail, because it was not worth much. That has become another story today. Even though the body has some modifications, the car is a genuine 1135, so I believe it keeps it value better as stock as possible. The MOT inspection issue was also a big contributing factor to rebuild the engine back to stock. It was to much problem over here to get it aproved with the turbo conversion. But as said, a bit of a pity, because it ran well for 40 years, and was very funny to drive!
Brg Jan

Very clever way to avoid detonation without a computer! I come from an era before cars used electronics. I'm currently using a Microsquirt to control spark retard, but I rather be using something analog.

 

[cbx6_79]

It's funny looking at the original 812 bottom end. How small the mains and caps are compared to the later 810 and every other 13/1400 that followed. Those pistons are not originals though.

The 812 is a bit skinny, but it held together well. You are right, the pistons in the pics are the Venolia 7:1 turbo pistons on their way out.
Jan

 

[ren5gord]

Early lancia Delta 8v turbo uses a twin choke blow through Webber.

Which will go on to a 5 gordini manifold if you re-drill 2 holes of the 4 holes.

I fitted one to a 5 gordini turbo years ago.

 

[DaveL485]

That looks fantastic in red!

I'd have kept the turbo though hahaha