Sly_G's GTS QV rebuild thread | Page 3 | FerrariChat

Sly_G's GTS QV rebuild thread

Discussion in '308/328' started by Sly_G, Dec 6, 2017.

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  1. Hinecker

    Hinecker Formula Junior

    Mar 14, 2011
    379
    Morning, my driving is combined, city, highway and back roads(passing other cars on narrow and curbed back roads takes some heavy acceleration...have say that this is where the fun starts).
    Could also be that US cars have lower compression and this makes the engine less efficient.
     
  2. kcabpilot

    kcabpilot Formula 3

    Apr 17, 2014
    1,527
    California SF bay area
    Full Name:
    Paul
    Another thing that US cars have that Euro might not is PCV (Positive Cranckcase Ventilation) there is an oil/vapor separator which is similar to the type used on Alfa’s throughout the 70’s through 90’s that is not always as effective as it should be and is prone to clogging. It should separate the oil from the extracted vapor and return it to the sump but it’s obvious from the insides of the intake plenum and tubes that oil is making its way past. But again this wouldn’t explain deposits on the back side of the exhaust valves which is something I had no evidence of.
     
  3. Hinecker

    Hinecker Formula Junior

    Mar 14, 2011
    379
    Morning Kcab,
    Exhaust valves have carbon buildup, not as heavy as the intake. Inside the plenum it looks quite clean...well, won't worry too much about this issue.
    Just as a question, have you installed or do you know anybody that has adapted a different type of fuel injection on this engine? If so, is there any improvement?
     
  4. kcabpilot

    kcabpilot Formula 3

    Apr 17, 2014
    1,527
    California SF bay area
    Full Name:
    Paul
    I don’t know anyone personally but there are plenty of cases where people have installed electronic fuel injection and even individual throttle bodies. I think both Nicks Forza and Scuderia Rampante have examples. I’m in California so it wouldn’t be possible for me to do any modifications like that.
     
  5. Hinecker

    Hinecker Formula Junior

    Mar 14, 2011
    379
  6. nerofer

    nerofer F1 World Champ

    Mar 26, 2011
    11,968
    FRANCE
    Great John, Thank you; will see if I can find something...

    Rgds
     
  7. Sly_G

    Sly_G Karting

    Mar 5, 2015
    123
    Lausanne, Switzerland
    Full Name:
    Sylvain
    Hi John,

    Thanks for hijacking my thread :)

    Just 2 quick points:
    1- I value your opinion but I had a total of 6 experienced (understand professional) engine builders actually looking at the block, including Ferrari specialists, 1 being the most reputable in the east of France that recently rebuilt an F40 engine. So far, after examination, all (understand 100%) opinions were to keep the liners as they are. Measurements check out on my end, thus so far I will go in this direction, unless I find concrete evidence that they need to be replaced.
    2- Feel free to start a thread on your build, that will be better to keep matters clearly separated without confusion.

    Cheers,

    Sylvain

    P.S: had no time at all to make any progress since the head work... so no progress report here.
     
  8. Sly_G

    Sly_G Karting

    Mar 5, 2015
    123
    Lausanne, Switzerland
    Full Name:
    Sylvain
    The engine had about 88kmiles. I am not sure on the history.

    The reason for the rebuild was poor compression on 6 cylinders (under 40psi). Explanation after disassembly was a timing issue (several, because there is evidence of another timing issue before).

    As for condition of the engine, all internals were in good shape, in comparison with other threads I have seen, with no unusual wear (see bearings pictures). One head was rebuilt (guides were new, came off really easy), the other head was stock (took a few months to take out). Guides on the original head were toasted. All was cleaned & replaced on both heads.

    I think this engine was freshly rebuilt, non professionally, and they messed up the timing.

    No need to say that I did not pay much for the car.

    I'll keep posting pictures as progress is made, which is slower than I wish...

    Cheers,

    Sly
     
  9. Hinecker

    Hinecker Formula Junior

    Mar 14, 2011
    379
    Morning Sly,
    Sorry!! I got a little carried away in this thread. :(

    John.
     
  10. Hinecker

    Hinecker Formula Junior

    Mar 14, 2011
    379
    Never the less, it was fun:)
     
  11. Sly_G

    Sly_G Karting

    Mar 5, 2015
    123
    Lausanne, Switzerland
    Full Name:
    Sylvain
    No worries!

    Cheers,

    Sly
     
  12. trs666

    trs666 Karting

    Apr 17, 2014
    83
    Göteborg, Sweden
    Full Name:
    Tommi S.
    Hineckerker, hydraulic tappets and timing chains are ok for minimising maintenance on dd running cars, button not good on HP engines,. Why? Hydraulic tappets collapse sometimes every while, they just loose the oil pressure,stocatically and for no reason, just happens. Maight be OK balance to service on a DD car but NOK on a Hp engine, yhe collapsing also gives you all kind of problems with uneven idle and HC values in emission testing. Cam chains work good on normal and even on moderate HP engines when correctly engineerd (look at VW:s 1.4 liter engine for one that was not) Maybe it was not sold in US but in europe second hand cars were completely cold due to camsheins jumping. Also if you use a ordinary chain, single or duplex, the camshaft movement is not even, it kind of hacks at every loop of the chain. Done lots of measurements and tests to verify both these issues at Volvo engine development laboratory. Morse chains as used for example the old OLDS/Rower V8 give an almost even camshaft rotation. ///TRS
     
  13. Hinecker

    Hinecker Formula Junior

    Mar 14, 2011
    379
    Good afternoon and Happy New Year!
    Sorry, I don't see the logic in your explanation...Why do modern Ferraris use hydraulic tappets and timing chains? My 328 gives out 260 BHP which is nothing compared to today's produced Ferraris.
    Another example: Japanese bikes have used timing chains since I can remember. If we talk about high performance and high revving engines you can't get a better example. A 600cc bike puts out more than 100 BHP and revs up to 14,000 RPM...Never seen a chain slip or break. Chains do stretch, that is true, yet you can't notice any loss in performance.

    Best from Spain
    John.
     
  14. trs666

    trs666 Karting

    Apr 17, 2014
    83
    Göteborg, Sweden
    Full Name:
    Tommi S.
    Hinecker, maybe i am a bit theoretical here, just what i learned from years of working with engine construction and optimisation on a major car company.
    We also use hydraulic tappets in production engines, but when we test in laboratory we see these things happen when monitoring real time combustion and emissions.
    Todays engine management systems can of course compensate for these irregularities with software optimisation so no major issue for road use.
    Om race applications solid tappets are still often used.
    I do not mean a well constructed cam chain can not take high revs and last long time, VW 1.4 and Audi V6 engines just show that sometimes manufacturers do not succeed in doing this correctly. Cost saving and shorter engines by using single chain instead of a double or a belt drive.
    On bikes it is another story, we do not expect bike engines last for several 100.000km:s as we do with car engines.
    ///TRS
     
  15. kcabpilot

    kcabpilot Formula 3

    Apr 17, 2014
    1,527
    California SF bay area
    Full Name:
    Paul
    Belts vs chains is not that simple of an issue and there have been technological advances over the past 40 years that have helped chains a bit, such as lightweight guides and tensioners but if they had been used as they existed in 1974 for the the F106 they would have added a lot of mass to the valve train and weight to the upper half of the engine. Belts are actually more robust and trouble free than a lot of people make them out to be especially in regards to the 308 design using two short belts on their own dedicated drive sprockets. It’s actually much better than many other v-engined designs of that era.
     
  16. Sly_G

    Sly_G Karting

    Mar 5, 2015
    123
    Lausanne, Switzerland
    Full Name:
    Sylvain
    Hi guys,

    Time for an overdue update! I am checking the site regularly but I am poor at reporting progress...

    The rebuild is making good progress.

    We came up with the engine strategy. We are keeping Nikasil liners (I found a way to new ones, not too expensive), and designed new pistons with optimized squish (far from ideal originally) and compression (11:1).
    The head cylinders have been rebuilt last year and surfaced. Pistons will be machined to be adjusted as best as possible. Along with the new pistons, new camshafts are being built (more longer duration mainly). Crank, stroke and bore will remain original. We had several constraints in mind for this build, including to be able to put everything back to stock if necessary.

    I'll definitely post pictures of the pistons and engine built once it is completed (over the summer).

    Waiting for the last critical parts to arrive, the engine is clean, alternator, starter, all electrical motors, master cylinder all rebuilt and ready to go.

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  17. Sly_G

    Sly_G Karting

    Mar 5, 2015
    123
    Lausanne, Switzerland
    Full Name:
    Sylvain
  18. Sly_G

    Sly_G Karting

    Mar 5, 2015
    123
    Lausanne, Switzerland
    Full Name:
    Sylvain
    Regarding the interior, this is also in progress. All carpets and leather are being re-done. This is where I feel lukcy, I live a few miles away from Molsheim, the place where Bugatti builds their cars. I got lucky to get in touch with a local manufacturer that does special projects for them. Very reasonnably priced and top quality (he works alone and does only a limited number of projects).
    Looking forward to see the result!!!

    These is when I dropped everyhting at his workshop.

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  19. Sly_G

    Sly_G Karting

    Mar 5, 2015
    123
    Lausanne, Switzerland
    Full Name:
    Sylvain
    And finally the injection. To get the best out of this engine I have to get rid of the K-Jetronic mechanical injection to install EFI.

    Following the advice of the much respected Nick Forza (many thanks again Nick for all the useful information you shared), I decided to go with the Link Thunder 8 cylinder sequential injection.

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    The question after was the throttle bodies. After a long time thinking about different solutions, I decided to go with a CBR 1100xx Blackbird injection system. The reason is that they are 42mm, spaced 85mm (pretty wide spacing for a motorcycle - still less than the 94mm required on a QV), easy to find in a good condition, have throttle position sensor, vacuum lines at each body on the head cylinder side all combined on a single sensor, and a nice fuel rail.

    Top
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    Now the question is how to adapt on the 308 head...

    Original
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    Got to connect this to that...
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    So I went ahead and used my poor engineering skills to create the proper coupler and 3D print it for testing

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  20. Sly_G

    Sly_G Karting

    Mar 5, 2015
    123
    Lausanne, Switzerland
    Full Name:
    Sylvain
    I could only print half of the model, but because the 2 twin bodies will be separated, this is fine to test proper design. Pretty happy with the results:

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    So all looks ok so far. I have to print the other half to fully test everything and get it machined in Aluminum if all checks out ok.

    Some progress, not there yet, but well on our way!!

    Cheers all

    Sly
     
    Milkshaker0007 likes this.
  21. mk e

    mk e F1 World Champ

    Oct 31, 2003
    12,899
    The twilight zone
    Full Name:
    The Butcher
    Are you planing to do any flow work?...its pretty easy to pick up 15+% onnce the CIS intake is gone ;)

    I have a set of 31.25mm (iirc) intake valves sitting here wishing they were helping someone make hp left over from my V8 days and are about the biggest that will sit on a stock seat.....$300? which I think is 1/2 what they cost me. Another option is 348 valves, 30mm iirc?


    Cam change planned? Once the CIS is gone you are no longer duration limited....just sayin.....
    Cool build.
     
  22. Sly_G

    Sly_G Karting

    Mar 5, 2015
    123
    Lausanne, Switzerland
    Full Name:
    Sylvain
    Thanks for the offer, but we are purposely keeping stock valve diameters. This might be controversial, but from what I understand, increasing CFM is not a universal solution for making power. In fact, optimizing intake diameter allows for exploiting gas inertia that dictates the rpms at which the engine will be able to operate. And despite popular beliefs, larger is not always better! Again this is just my humble understanding.


    Absolutely and ordered :)
    Aiming at 250deg @ 1mm.
     
  23. mk e

    mk e F1 World Champ

    Oct 31, 2003
    12,899
    The twilight zone
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    The Butcher
    What you're saying sounds right in general. The HP here comes form better intake to exhaust matching. The stock heads the ration is about 92% which is a lot of exhaust flow, so bumping the intake up and leaving the exhaust stock get you a bit better ratio and will let it pull to a bit higher rpm, were the velocity is again high.

    On the stock engine the CIS plenum pretty much instantly becomes the restriction is you touch the head so its a hard fight, but in your case with the ITBs I thought in might help to add a bit more flow on the intake side.....it will run good either way though I'm sure so carry on.


    Nice, that sounds like a good option....and just about exactly the duration I picked for my engine :)

    How much lift are you planning?
     
  24. Sly_G

    Sly_G Karting

    Mar 5, 2015
    123
    Lausanne, Switzerland
    Full Name:
    Sylvain
    Thank you for sharing your thoughts and analysis! Indeed, we will not touch either exhaust or intake ports / valves diameters. As you mention, my impression was that the biggest restriction was with the CIS plenum so going with throttle bodies should definitely free lots of available power. It certainly would have help to touch up the intake and exhaust ports & valves, but I think most of the power loss is in the plenum. So the most power gain to $$ seems to be in the intake plenum and cam profile. We'll see the results :)

    Stock lift. We'll see what we get. Along with a good piston design, it's still possible to change cams :)

    If you don't mind asking, what duration / lift are you planning?
     
  25. mk e

    mk e F1 World Champ

    Oct 31, 2003
    12,899
    The twilight zone
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    The Butcher
    I think just replacing the CIS with ITBs will gain you about hp20 so nothing to laugh at for sure.

    my cams, with lash set so valve timing are
    @.006" 273/285
    @.050" 241/247

    lobe timing is
    @050" 247/251

    Lift at the lobe
    11.5/10.6mm

    This is in my frankenferrari.....TR heads on 400i block, in a 308. The TR heads are very similar to QV, stock flow is virtually identical (94cfm@10" vs 93cfm@10) but QV are a little straighter and easier to improve, still with some effort(ok...a LOT of effort) I got it up to 156@10" with the manifold and TB in place so quite a lot more air. IIRC stock TR cams are the same as stock 328 cams, which is a just little more lift on the intake than QV, but the same exhaust..
     

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