A Riviera scratchbuilt GT40

I plan to use 15W/40 mineral oil with ZDDP additive for the break-in , despite I have roller lifters ...


Check out the VALVOLINE VR1 Mineralic 20 W 50 it is realy a good oil. Other than that i´m using ZDDPLUS to bring up Zinc and phoshat level to above 2200 PPM ( VR1 original still has about 1400 PPM, which is 100% more than in most street legal fullsynt´s with about 500 - 700 ppm))
also it stays quite viscous in higher temperatures and therefore is not easy pressed and squished away.

Cam and Flat tappet lifters look like new on my car after 4500 km.

Very valuable information Tom...I am going to investigate this solution . It is now clear for me that the main point is to keep the ZDDP level at a sufficient amount , either with an "old school " oil, or with a correctly rated one, slightly upgraded ...

Since last post, I focused mainly on priming fuel system and oil distribution ; and thanks to good advices I received on the previous posts, everything went OK :

*Fuel : I installed dummies tanks ( Definitive parts still to build!) with 10 liters and 5 l plastic cans ...pick up at the very bottom, and return visible from the opening .The carb is not yet connected and 100 % goes to the regulator return line .

After 4-5 s priming, the fuel pressure stabilizes nicely at 5.5 psi ; switching
( 2 x 3 ways valves) on the other thank takes 2-3 s and pressure is the same.

As expected , the Carter 4601 pump is a little bit noisy ....

*Oil system : I finally decided for 15W-40 mineral Schell Helix oil, with ZDDP additive .As visible on the picture, I made a removable bracket which holds a 500 W electric drill ; I use the original belt , disconnected from the cranck pulley , to the drill pulley.
After 23-30 s initial priming the oil pressure goes up to 75 psi and keeps very stable .I suppose that it is from pump pressure regulator action ...

I operated with cold oil , and as expected , TOM, the electric drill came to eggs coocking temperature by the same time! But still working ...

The valvetrain got lubed in sequence and I made the 90 ° rotation procedure.

I decided to make the first starter rotation test : OK, without, and with the spark plugs .

During those sequences , I noticed that the lifters bleed-down within a few minutes , and not all at the same rate ...

Is it something I should take care of and investigate ?

From a few Web investigations, I did not found a precise answer...



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An important step was made last week on my build : FIRST ENGINE START ....

With support of Mark,( 454 Cobra owner and builder ...) we powered the engine for the break-in: it started immediatly, despite a low battery, and performed the 20 minutes break-in at 2000-2500 RPM without issues ...

The oil pressure (Dry sump system) started at 75 psi and came to 50 as water temp was growing

The water temp was at 100 ° C at the end of the sequence we made with hot summer weather, in the garage ....; the remote thermostat ( radiator by-pass) opened at 80 °C as expected , within 7-8 minutes.

The vibrations are very low ( At the low break-in RPM...) : can be the addition of crank internal balance, poluyrethane bushings , and flywheel specific balance ?

As the car is still on the building bench , I tested the gears selection :OK ; no unexpected noise came from the box , neither from the clutch ; this is encouraging for the future , but not very representative as there is still no torque on the drivetrain .

We made a short video sequence ( VLC .mov, 5 mB ), but I am unable to attach it to the post, sorry! Any advice will be appreciated ...
Hello René,

Here is your vid !

GT40 first start - YouTube

Serge send it to me, and to be able to publish it few days ago on the french forum you know, I've had to put it on my youtube account. If you mind it, let me know, I'll remove it.

Maybe somebody could have a better solution ? No way for me to have the youtube window directly opened in that post !

Pierre-Louis (Bob, on some other place ;))
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Thank you very much Pierre-Louis/Bob , you did it right !

And this is a nice exemple of synergy between forums !

See you next time in this one or another ....

Hello René
yes that's a good step!!
But does this means that you already achieved all electric harness for the whole car or did you built only an engine test harness ?

Keep your good work

may be we soon will test our cars on track on same time ( LOL ) my 908 replica is on a good stage too !!!
Hello Markus, Mic,

Yes ,I am pleased from the sound and the level is surprisingly moderate ( At low tested RPM ) ....

The mufflers are Pypes Performance M 80 , 4 " external diameter which I selected from good anounced attenuation and also good feed-back on some forums.
I plan later to perform some sound measurements at higher RMP ..Wait and see...

Mic, I installed the definitive electric harness on the chassis up to the connectors for the front and rear clips( Schematics shown on post N° 105).
A long process I am glad to have behind me !

I still have to test the alternator ( Not connected for the break-in )and install the remaining instruments and switches on the dash-board...

Nice to see that your 908 is on a good stage ( Never doubt on that !) Do you have recent pictures , or posts on the project ?

Hello Markus, Mic,

Mic, I installed the definitive electric harness on the chassis up to the connectors for the front and rear clips( Schematics shown on post N° 105).
A long process I am glad to have behind me !

I still have to test the alternator ( Not connected for the break-in )and install the remaining instruments and switches on the dash-board...


Yes indeed connecting all the main harness is something nice to achieve but lot of work ( I just finished mine during Holidays !!)
some pic with 908 bodywork and suspension fitted before to have the chassis epoxy painted (this will be ok from subcontractor coming back home)
Keep on your good work ; hope to watch some good progress of your nice GT 40 in august !!


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Very , very nice job you did there Mic ! This chassis is an "oeuvre d'art" ..
Do you really need to install a body on this metal sculpture ?

I am joking of course , the Porsche 908 body as the same hudge "speed evocation power" than the GT40 has ...

Now , we are all waiting for the "engine start video" as a prelude for the " first track test" video !


Ian Anderson

Lifetime Supporter
It is fantastic to see some French builders.

Will you be able to get the cars road registered in France now or do the authorities still not allow home built cars?

Well done

Many thanks René
Today is coming back from Dordogne camping week and monday at work again ( lol)
Beg you pardon for having hacked your nice thread for that pics post !!

What are you sourcing for your wheels 15 " ? and tyres ?
Ian, thank you for your encouragements to the French builders !

Effectively, the French kit car registration is still a blocking point ....The authorities does not forbide the kit car registration , but they have almost the same administrative process to perform than an industrial builder!
There is no SVA procedure

The other alternative is via the "Collection car" status ; but you need to prove that the chassis ( Or part of ...) is more than 30 years old ...

So my starting program is track use ....

Mic, have a good restart after holidays!

On the wheel subject, in fact , I will go to 17" rims from Team III
( Halibrand) in order to install more than 300 mm diameter brake rotors , and have a wide open choice for the tires ....

After the break-in sequence, I when ahead on the build with a specific air-cleaner box ....

And I have to admit that I did not resisted to the idea of installing dummy trumpets on the air-cleaner box! As visible on the pictures...Hum ...

Obviously , I have to apologize for those who spend money and time for full "historic" Weber carbs and trumpets; but I confirm that the next major evolution which is already decided on the engine, is an EFI conversion with 8 throttles and trumpets !

More seriously, I am now looking for the optimum engine adjustments: Ignition, AFR etc ...

And I am going to connect a wide-band O2 lambda gauge ( Not permanent ) in order to have an exact information on the AFR ; I suspect it to be in the lean area at middle range, due to quite hot headers....


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Your special velocity box is very very "smart" !!!!
this allow you to wait for your new injection system ;are you using some Jenvey kit ? seems they are not so badly manufactured.

I think you are thinking to improve your engine injection to win our future track day
"encounter " LOL..... GT 40 VS 908 !!! in memory of le mans 69 big battle
Am just working too on my RSR engine to have it ready to fit it on the painted chassis
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There is also this supplier ( stackinjection) doing anice kit ;

Australian supplier


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