A110 - 807/841 engine to 1774cc
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Thread: A110 - 807/841 engine to 1774cc

  1. #1
    Fellow Frogger!
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    Default A110 - 807/841 engine to 1774cc

    Thinking of upgrading the A110 engine in my R8G from 1605 to 1774 cc. Although the 1796 cc looks even more inviting, it is just a road car and there is very little block left after it is machined for 86 mm o.d. liners.
    Anyone have any experience, thoughts?

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  2. #2
    1000+ Posts Frans's Avatar
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    Hi. Yes I have built a 1800 for an A110 GRP 4. Actually fairly easy if you go the Salv Sacco way. Not sure if you know him but he has proven kit that can do it.
    The sleeves have different bores depending on your needs. On the big bores the pistons donít go to the top and flush with the block they sit a little lower and the bore on top is standard size for you to use standard head gaskets. It works well.
    Donít have any details specs here at work but can get more if you want.
    Frans.

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    Thanks Frans, I have previously bought some new 45DCOE manifolds from Salv at a very good price. I will look into what he can supply.

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    I have checked with Salv Sacco who has quality 82.5 mm forged pistons and his liners are slightly improved over the Mecaparts liners.
    Apart from being very helpful, I don't have to worry about the occasional French translation problems you sometimes get with Mecaparts.

  5. #5
    1000+ Posts schlitzaugen's Avatar
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    What are you chasing?

    Power?
    ACHTUNG ALLES LOOKENPEEPERS

    Das computermachine is nicht fur gefingerpoken und mittengrabben. Ist easy schnappen der springenwerk, blowenfusen und poppencorken mit spitssparken. Ist nicht fur gewerken bei das dummkopfen. Das rubbernecken sightseeren keepen hands in das pockets-relaxen und watch das blinkenlights.

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    1000+ Posts renault8&10's Avatar
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    Quote Originally Posted by schlitzaugen View Post
    What are you chasing??
    RS Clio’s!
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    KB


  7. #7
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    I can pass most on the track and stay in front, but I want to make it easier as I get older. It can be very hard work.

    I am after more torque as I am also going up to a 3.5 diff from the 3.7. I will be able to save a couple of gear changes by staying in 3rd in at least two corners at Eastern Creek.

    I will also get a higher top speed on the straight with more torque and the taller diff, I will not have to rev the hell out of it.

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    1000+ Posts schlitzaugen's Avatar
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    I see.

    But I thought you said it was a street car hence my question.
    ACHTUNG ALLES LOOKENPEEPERS

    Das computermachine is nicht fur gefingerpoken und mittengrabben. Ist easy schnappen der springenwerk, blowenfusen und poppencorken mit spitssparken. Ist nicht fur gewerken bei das dummkopfen. Das rubbernecken sightseeren keepen hands in das pockets-relaxen und watch das blinkenlights.

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    It is a street car, very calm on the road, mild cam, not noisy, looks old and standard, keeps up with modern traffic. Then at a track day, I get to drive it like we did in the early 1970's and its much faster than most late model Renault "sport" variations.

    Brettr's supercharged car is a Sydney daily driver and mine is much milder than his beast.

  10. #10
    1000+ Posts schlitzaugen's Avatar
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    What spec is your 807 now? R12G? Above?
    ACHTUNG ALLES LOOKENPEEPERS

    Das computermachine is nicht fur gefingerpoken und mittengrabben. Ist easy schnappen der springenwerk, blowenfusen und poppencorken mit spitssparken. Ist nicht fur gewerken bei das dummkopfen. Das rubbernecken sightseeren keepen hands in das pockets-relaxen und watch das blinkenlights.

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    The engine is probably close to 12G spec, built by Bruce Collier it had EFI when I acquired it. Claimed to have ďall the good gearĒ with nearly 200hp on injection. I never believed that but it is a sound Collier engine. The injection never worked efficiently which is why the engine became available. I sold the injection and went back to two 45 DCOEís so the engine bay looks more like a Gordini.
    I took the head off to find it was around 1600 with standard rocker gear, nothing really special about the head. It has forged pistons but I doubt there are any H beam rods for big revs as the cam runs out of puff at about 6500 rpm. That suggests a rally spec cam as evidenced by the pretty basic rocker gear.
    Considering all that, itís remarkably fast compared to Renaults current offerings and after sitting in a paddock for nearly 20 years, that engine is not too bad in the back of the car I built for it.
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  12. #12
    1000+ Posts Frans's Avatar
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    Quote Originally Posted by Bustamif View Post
    The engine is probably close to 12G spec, built by Bruce Collier it had EFI when I acquired it. Claimed to have “all the good gear” with nearly 200hp on injection. I never believed that but it is a sound Collier engine.
    I took the head off to find it was around 1600 with standard rocker gear, nothing really special about the head. It has forged pistons but I doubt there are any H beam rods for big revs as the cam runs out of puff at about 6500 rpm.
    As you said "I never believed that". It is almost always an over estimate if you speak to owners about their car's HP. One will have to go very high-tech and very hi-equipment to get a 1600 8 valve NA pushrod motor to make that HP, if ever.

    FWIW. Something that I experienced Bustamif, is that the 1800 I built peaked out at 190 flywheel HP after all our development. Obviously I de-tuned it for the customer because of the Targa long distances. In this de-tuned condition (175HP FW) we experienced on two occasions that after 2 Targas we had a cracked crank at the flywheel end journal. This is logical because all the power of the 4 cylinders is added at the last journal to transfer all the power through to the gearbox. That means about 1500 - 1600 km of special stages and a good 4000km cruising between stages. This is just to give you some info on the strength of a standard crank.

    I don't think you will do a 1500km at the track days but just incase you enter the Bathurst 1000.

    Fans.
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    Young enough to do it anyway.

  13. #13
    1000+ Posts driven's Avatar
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    No one seems to mention OS inlet valves. Can add more HP for little effort

    As good as many. Maybe why running out of puff at 6500rpm, should be suck actually

    High Performance Math

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    That's exactly the type of accurate practical info I was hoping to get for this project, thanks Frans. The number I am aiming for is 165-170hp.

    Interesting about the flywheel end of the crank. The big engine in the Lotus cracked the block on the flywheel end after two race meetings. After welding in some reinforcement and re machining, it has now done three race seasons with no signs of block stress on the last inspection. The crank will be crack tested next rebuild!

    Targa events would probably put more load on the end of the crank than smooth circuits due to the bumps and surface irregularities. I avoid some tracks which are way too rough.

    I have a few spare 807/841 doner engines, heads, cranks, valve gear etc so I have decided to build a fresh engine rather than rebuild the one in the car. Just a matter of finding the spare time and money now. The big expense is the piston/liners, the rest is mostly time.

    I will use the same carbs, change jets, chokes and swap the headers, alternator etc.

  15. #15
    1000+ Posts Frans's Avatar
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    The 165-170 will be easy and reliable and I am sure that you will get that from 98 octane as well.

    Frans.
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    Young enough to do it anyway.

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    Quote Originally Posted by driven View Post
    No one seems to mention OS inlet valves. Can add more HP for little effort

    As good as many. Maybe why running out of puff at 6500rpm, should be suck actually

    High Performance Math
    That's a good link. Although the 1605 engine drops off at 6500, the car with the 1980 cc (plus) has standard valves and pulls like a train to 7200 where the soft limiter cuts in. That's a tad over 240 kph at Phillip Island according to the data download.

    I intend to go to bigger valves with the new R8G motor. I seem to recall Alan Moore from here on AF mentions some valves with a 7 mm stem diameter to reduce port restriction on 807 heads.

    And for the last few years I have set every car to run 98 octane fuel.

  17. #17
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    I like the SENSE being talked here. People keep on asking for 170-180 hp motors to be built, and first thing I ask are you willing to have it rebuilt in 2 years, or a new motor built. And they look at me crazy like. Then I explain that if you want that kind of HP and last 50K km then you need "H beam" rods and a billet crank and real forged pistons, and another $20K. And still I will limit it at 7500RPM as they will run out of air (and torque) at 7200RPM. And not to mention the extra drive train needed. And you will have difficulty driving it on the road in traffic.

    Take care,
    Ray
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    Ray geckoeng

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  18. #18
    1000+ Posts schlitzaugen's Avatar
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    The 807 in my 17G runs out of puff at 6500RPM and that is just a standard 120HP engine. I think Frans is at the very limit of what you can expect to get out of 1800cc from an engine like that. 100HP per litre is easy to get with four valves and modern injection but even modern engines don't really go there. In light of your previous statement about torque I would be curious if you could increase the torque without necessarily upping the power that much (the crank would still have to be strengthened especially if you're going to push more torque through). Kinda like what Renault did with the Virage compared to the "normal" 12.
    ACHTUNG ALLES LOOKENPEEPERS

    Das computermachine is nicht fur gefingerpoken und mittengrabben. Ist easy schnappen der springenwerk, blowenfusen und poppencorken mit spitssparken. Ist nicht fur gewerken bei das dummkopfen. Das rubbernecken sightseeren keepen hands in das pockets-relaxen und watch das blinkenlights.

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