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Thread: N/A YB Build - RSA Build

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    N/A YB Build - RSA Build

    Well lets get something going...

    Stripped head of valves etc. Nothing special to report.

    Head has a good "turbo" port job but not good enough for NA use.

    Standard intake valves have just been cleaned up in a lathe by the looks of things

    Bright side all valve guides are still good.

    CC'd chamber at 47.1cc
    Head skimmed to 137.4mm

    My concern is will valve pockets in Wossner pistons be deep enough for 13mm lift on the cam we are using and if not will there be enough meat to machine pockets deeper as the head has already been skimmed so much.






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    Re: N/A YB Build - RSA Build

    Could I just slot rod like this instead of drilling oil feed hole in bigend ?

    Last edited by DarthVader; 31-08-2012 at 23:09.

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    Re: N/A YB Build - RSA Build

    When i was going to have my rods oil feed drilled, the guy in the machine shop showed me some toyota steel rods ,and thats exactly how those were done , same as you ve have , seems they all are .

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    Re: N/A YB Build - RSA Build

    dummy build the engine put some dum dum on piston to check clearance

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    Re: N/A YB Build - RSA Build

    Quote Originally Posted by DarthVader View Post
    Could I just slot rod like this instead of drilling oil feed hole in bigend ?

    I was told by a well known engine builder that the rods dont need that maching as "theirs enough oil splashing around down there" so I didnt do it to my engine and its now done 20,000 miles,

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    Re: N/A YB Build - RSA Build

    Thanks, I'll do the slot as there will be a crank scrapper and proper baffled sump so there hopefully there won't be so much oil flying around in the crank case.

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    Re: N/A YB Build - RSA Build

    Quote Originally Posted by DarthVader View Post
    Could I just slot rod like this instead of drilling oil feed hole in bigend ?


    Feed hole for what ? - remember the small end is not pressurised like the big end.
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    Re: N/A YB Build - RSA Build

    I grind a slot in the centre of the rod facing straight up to the pin, a little extra oil going up to the pin is not going to hurt anything, as you said when running a crank scraper there is a lot less oil going around with the crank, no harm in sending a little more oil up to the piston for the sake of grinding some small slots/grooves in the side of the rod, certainly no need to drill the rods
    "Horsepower sells cars, torque wins races" - Enzo Ferrari

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    Re: N/A YB Build - RSA Build



    This is the mod I was revering to

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    Re: N/A YB Build - RSA Build

    Do a dummy build with some weak springs in no1 inlet and no1 exhaust valves, say the very front valves, then set the valve clearance, now fit a dial gauge on to each lifter, time in the cams as normal, now check the valve clearance by levering/pushing each valve further open until it touches the piston, take note of how much clearance there is on both valves and re check at several different positions, the closest point for the inlet valve will be somewhere between TDC and 15* ATDC, the exhaust valve will be closest to the piston from 15* BTDC to TDC, usually the closest point will be 7*each side of TDC for both valves but it is best to check the clearance at several different points to find the tightest spot

    Now adjust the cam timing al little, advance the inlet cam a few degrees, retard the exhaust cam a few degrees and check what clearance you have now, it will be less for both valves than before, you need to know there is enough room for adjustment at the dyno/rolling road without fear of bending any valves

    Aim for 2.5mm clearance for both valves, the inlet being most critical as they are the heaviest valves and much more likely to bounce/float at any given rpm vs the same spring pressure used for both inlet and exhaust valves

    2mm clearance would be rock bottom with stiff springs but personally I would not want to use less than 2.4 to 2.5mm

    The maximum valve lift of a profile has almost nothing to do with how much lift the profile has at tdc, what does matter is the low lift duration
    and inlet + exhaust cam timing specs, for example a cam with 14mm lift and low duration may not need deep valve reliefs where as a cam with high duration and 11mm lift may need very deep valve reliefs, the quoted lift figures at tdc are a good indication of how deep the valve reliefs need to be, lots of lift at tdc = deep reliefs and if it has long or short seat timing
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    Re: N/A YB Build - RSA Build

    Quote Originally Posted by DarthVader View Post

    This is the mod I was revering to
    Yes that is what I was thinking of, drilling holes like that is completely unnecessary, just grind a simple slot each side and be done with it

    Some of the information in the book that picture came from is very misleading, especially ignition timing, carb settings etc, utter BS
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    Re: N/A YB Build - RSA Build

    Thanks for that info on cam checking, I've got to get into having to deal with an extra cam

    I'll just slot both sides of rod.

    Just for interest ran spec's threw Dyno 2000 software. I've used this before with an xflow build and with the last 2.1 race pinto I built. With the Xflow it was out by 6Hp and with pinto 3Hp compared to Dyno runs.



    Excuse typo - intake valve size is incorrect

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    Re: N/A YB Build - RSA Build

    Havem't forgotten about this thread,

    Customs have hit the jackpot with our stuff :-(

    Anyway,
    Burtons goodies are here
    Pistons should be shipped this week

    Customer now needs to dig deeper into his pockets to get the cams here

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    Re: N/A YB Build - RSA Build



    Head was taken in for porting and thats when I was basically removed from that side of the project. Custom cams where cut of unknown specs - 12.6mm lift I am lead to believe - waiting on spec sheet for cams...

    Got a call from owner telling me they have hit a snag with the head, the cams don't turn in the head, so material needs to removed from the head for the cam lobes to clear. Is this a common problem ? Because as I mentioned to the owner Catcams don't mention any clearance machining with their 12.8mm lift cams.

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    Re: N/A YB Build - RSA Build

    Got a call from owner telling me they have hit a snag with the head, the cams don't turn in the head, so material needs to removed from the head for the cam lobes to clear. Is this a common problem ? Because as I mentioned to the owner Catcams don't mention any clearance machining with their 12.8mm lift cams.
    im not suprised, i've heard that before when it comes to megga lift cams, but as most yb cams have nothing like that much lift you wont come across it often

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    Re: N/A YB Build - RSA Build

    Apparently common problem on Vauxhaul 16V heads. Hoping to get the head back late next week as the lifters are being converted to solid and shimming done - pics will follow then.

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    Re: N/A YB Build - RSA Build

    the schrick cams in my bmw have the same issue

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    Re: N/A YB Build - RSA Build

    Glad I'm not doing the grinding :-)

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    Re: N/A YB Build - RSA Build

    That is a good problem though, it means the cams have decent valve lift, it is a common modification, usually done with a die grinder with a carbide burr or in a mill, you basically remove some more material from the lifter tunnel notches to clear the higher lobe height, any head porter will be able to do this with his poritng tools
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    Re: N/A YB Build - RSA Build

    Quote Originally Posted by RWD fords rule View Post
    I grind a slot in the centre of the rod facing straight up to the pin, a little extra oil going up to the pin is not going to hurt anything, as you said when running a crank scraper there is a lot less oil going around with the crank, no harm in sending a little more oil up to the piston for the sake of grinding some small slots/grooves in the side of the rod, certainly no need to drill the rods
    Sorry to jump in here,but can you tell me if you put a slot in both sides of the rod?

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    Re: N/A YB Build - RSA Build

    Yes both sides, doesn't need to be a big slot, I use a 3mm wide grinding disc in a dremel, round off the corners of the grinding disc first so that it cuts a U shaped channel rather than a square shape, square corners are stress risers long term, might not make any difference in this area but good practice to use a radius/fillet shape rather than sharp square corners
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    Re: N/A YB Build - RSA Build

    i've done it with a triangular file, it literally only takes seconds

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    Re: N/A YB Build - RSA Build

    Thanks for the info.

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    Re: N/A YB Build - RSA Build

    This is some snaps of N/A YB I've started building for myself - road going car

    Toyota 21R Pistons
    BMW M20 conrods
    Crank stroked - 85mm
    92mm bore
    CC - 2260cc
    CR will be +- 10.5 after final valve cutouts have been done.
    Plan to run it on bike carbs or bike throttle bodies
    Hi flow oil pump that has been "port flowed" as per RWD Fords Rule



    Because bigend journals are narrow that pinto's I needed to space the rods on small end side.




    Now just need to find set of cheap N/A cams

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    Re: N/A YB Build - RSA Build

    Friday evening I finally got the head back for the race car motor that started this thread.

    Not complete yet, but 4 valves fitted with shimmed lifters, PAC Gold valve springs. Enough for me to do dummy build with.

    Obligatory porting pics :






    Heads not in the best of nic, and skimmed previously to the max, no space for bigger valves so will be using standard valves for now until we can find a decant head next year.


    Had to grind head to get clearance for the cam's to rotate in the head



    Fitted set of Kent veriers, not the best of fit - even checked them on a set of standard turbo cams.

    More pics of dummy build tommorrow.

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    Re: N/A YB Build - RSA Build

    Got specs for cams - believe it's 16V golf grind



    Seeing that I will be doing a few pinto's I decided to build some "tools" to make life little easier

    TDC Stop




    Degree wheel pointer




    Degree wheel mounted on bush that I can lock onto crank snout and then rotate crank without disturbing degree wheel. To move degree wheel I simply loosen lock bolt turn degree wheel and lock again.

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    Re: N/A YB Build - RSA Build

    Hello DarthVader!

    Did I miss something ? Which camshaft combination you end up for the 13 to 1 CR race engine for your customer ? Any of the Catcam profiles as RWD ford rules adviced ? I also found them very inetersting but I wonder if any of those profiles need deeper than existing pockets on the Wossners ? Have you evaluate all the other n/a YB profiles in the market ?

    Also, are you going to use the Pinto style V.Reinz gasket or is there a YB version of the said V.Reinz gasket ? I am also concerned with different pattern of the water circulation holes in the YB head above the Pinto block.

    Regards,

    Kerem

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    Re: N/A YB Build - RSA Build

    Hi Kerem,

    The customer I'm building the motor decided the cams from Cat where to expensive, so he decided to have a set of cams locally cut. The grind is that of an old Schrick VW Golf 16V grind from the touring car series (found this out Friday) This is also the cam specs I posted above.

    I did a quick dummy build and yes there is going to be problems with valve clearance as can be seen with a lift of 4.5mm at TDC - Unfortunately I only had a hour or so to do a quick test. I don't see the Wossner pistons having enough crown thickness to accomplish the required depth pockets. I see this being a total cock-up Fortunately / unfortunately I was not consulted when the cam profiles where chosen.

    Think this is what is going to be needed in the end http://www.mooregoodink.com/news/eng...mber-mold-kit/
    and a set of custom pistons made

    I ordered 2 YB gaskets for this YB build.

    I have compared the YB gasket to a standard Pinto gasket and I am sure a few cutouts with a hollow punch would accomplish the required cooling holes

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    Re: N/A YB Build - RSA Build

    Hi DarthVader,

    Ok, I understood. It is a pity that you may be having some mismatching components during this build. However, you may still get away with that lift once you time the cam properly. On my Yb built with unknown profiles (Based on reprofiled standart YB cams ) inlet valve lift has to be 5 mm @ TDC and the exhaust valve lift has to be 4.25 mm. When I set this up timing with the Wiseco pistons running 0.10 mm over the deck with 1mm Felpro, I was not having any problems with it. As of this moment, I do not remember the depth of the v.pockets but I may be able find the piston's custom production data sheet. I do not know, may be it helps. I do not have much experience with YB s and I am learning especially with the great help from Rwd Ford rules. Obviously, the camshaft profile will have different efects as far as the valves to piston proximity not only at TDc but also at other known angles. So my camshaft example could be totally irrelevant to your build.

    Regarding the camshafts for a proper n/a YB, really there is not much choice other than the nice profiles as suggested by Jason. His Catcams suggestions definetely worth considering. It seems that Piper and Kent profiles does not have high lift low duration combinations which a high SCR YB really needs. I am sure good YB builders get their own profiles cut.

    Referring to the deep pockets issue, you are right. Eventhough it is not directly related to the max lift of a certain profile, if a chosen profile requires a deep pocket than the hardly gained chamber volume may easily be lost. Then as you mentioned, it is time for custom made pistons.

    Are the Yb gaskets 1.25 mm or 1.50 mm ?

    Regards

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    Re: N/A YB Build - RSA Build

    Thanks for the feedback, I am in the same boat as you, also new to the YB motor.

    You may be correct, with some more time I might be able to get the cams set up correctly. I hope to have the head back from engineering in the next week or so.

    Did you have the standard cams metal sprayed and then reprofiled ?

    The CatCams option was on top of my list, but as I said before I am not the one with the cheque book.

    What duration are your cams ?

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    Re: N/A YB Build - RSA Build

    I have not got the cams reprofiled, the owner of the engine brought the head as a package to me. The head was ported and the camshafts were re profiles in Finland when he bought the set up as used.

    Due to time shortage for the season, I just build the engine and timed the cams according to the seller's advice. As I mentioned the inlet cam was timed with 5mm @ TDC which is quite a lift for YB. Once, I tried to retard that timing and the performance decreased. However, this engine is built with 11 to 1 SCR and I think this is pretty low and I should soon much higher compression for better torque and power.
    Unfortunately, during the build, I did not map these camshafts which I really should. Very soon, I am going to rebuild the engine with higher CR and I will definetely map the cams. Meanwhile, I am planning to get pair of those Catcams Yb camshafts for another YB build. Jason adviced 3 very interesting profiles to choose from and on paper they also seem much better than the Kent or Piper ones.

    My friend bought an interesting YB from USA an I am also looking after that engine. Basic spec details are, 84 mm stroke, 94 mm pistons build with US spec alloy Pinto block. These engines were used on Historic face carsisi in the US. The cylinder head is YBM which I beleive it is from Cosworth and ported and prepared at Cosworth. The inetersting part is, I can not identify one of the camshafts ( again, not much info came about the camshafts during the purchase ). The codes are DA19 and EA26. the DA19 is a mild Kent profile with 11.4 lift ( according to the todays Kent catalog ) probably originated from Cosworth but I could not identify the EA26 yet. I guess I have to do the full cam mapping to undertsand their specs and charecteristics. This 2.3 engine is also build with 11 to 1 SCR. Now the engine is on the bench and I will do something work on it soon hopefully. Due to our regulations here, I may not be able to build this engine in its 2.3 form so I am actually planning to use the head with more aggresive camshafts from Catcams and build a 2.0 lt bottom end engine with a CR of 12.20 - 12.50. The problem is most of the camshaft data advertised does not much the real world so a big investment on YB cam kit from any manufacturer is a difficult decision.

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    Re: N/A YB Build - RSA Build

    The US Pinto block from the 2.3 Mustang is longer than the European spec pinto. So how is the YBM head going to fit a European spec pinto. Maybe I miss understood you - and the block you have us a european alloy block.
    I would love to see some pictures of it as well as the porting that was done on the head, do you know any power figures ?

    I was very tempted to go 94mm bore with my N/A YB that I am building for my road car, but decided against that and leave some meat on the bores for future re-bores if need be.

    We got valve springs and retainers from PEC - bee hive springs that can coupe with the valve lift

    Probable reason why you can get away with 5mm valve lift @ TDC is your cutouts are deeper than those of the Wossner pistons hence your CR of 11:1

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    Re: N/A YB Build - RSA Build

    Our is the European Pinto alloy block but made in USA. It is neither same with the one Burton' selling nor the Smith And Jones's. I will not be able to upload photos here but I can e mail them to you if you like. For the head, I will take some photos over the next few days, it may be helpful to you during your head porting.

    Regarding the 94 mm bore, I have used 93 mm in a Pinto but would not like to go beyond that. In Finland, in Group F rallying, they frequently use 94 and larger bore with some specially made liners. Usually they use heavy duty good quality truck liners if I am not wrong. They really like to go roller camshaft and large bore combinations with some wild camshaft profiles overthere.

    I believe that using an old block with certain amount of corrosion already set in the cylinders ( outer sections were the water passes ), for a reliable engine 92 mm is much safer.

    Are not there any suitable Kent double springs to coop that valve lift ? If I remember correct, Iskenderian doubles could also work according to the Des Hammill book. May be I am wrong. However, I think by going the bee hive spring way, you have chosen the best.

    In that 11 to 1 CR YB, unfortunately pistons had very small domes 5.8 cc ( they were custom made Wiseco and I have spec sheet if you like ) which did not help much to raise the CR with the 50 cc chamber volume. I am not happy with that combinationa and I am quite sure that engine will perform much better with a higher SCR when I built it again. I do not exactly remember the depth of the v.pockets but it should be in the custom order sheet of the Wiseco which is not in this computer but I will find it.

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    Re: N/A YB Build - RSA Build

    Hawk some pics would be interesting. The head I am using has already been finished porting, but it will be interesting to compare the two different heads.

    We have used 94mm bore with diesel truck liners as well. Works really well and have not had failure with them. This method was used along with Wieseco XT550 pistons, I would like to try XT600 pistons @ 95mm bore

    Back to N/A YB

    We got PEC bee-hive springs that where spec'd for the high lift cams - so that problem is sorted out.

    Squish is very important and flat top pistons are not the way to go with YB build.

    I also have spec sheet in PDF of the YBM build data if you are interested - PM me your email and I can email it.

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    Re: N/A YB Build - RSA Build

    Im running DA2 cams in mine but a little lairy for a road car i think. I have another pair in but need the long dick valves to get the lifter clearance or lash caps making
    http://www.turbosport.co.uk/signaturepics/sigpic12022_2.gif

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    Re: N/A YB Build - RSA Build

    I might be missing something but how are you getting big compression numbers if you are talking 5mm of lift at TDC as my own engine runs 0.245" (6.2mm) lift and I can't get any more than 11.4 with a lot of welding to the chambers

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    Re: N/A YB Build - RSA Build

    Mine is with 92 mm bore, 50 cc head, 5.8cc dome volume, 1 mm headgasket, pistons 0.10 mm over block

    Unfortunately the CR is only 11.02 with the above config.

    I am now getting larger domed pistons custom made hopefuly and will probably use 47 cc head and plan to use some profiles with an inlet lift of less than 5 mm @ TDC.

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    Re: N/A YB Build - RSA Build

    When you say 5.8cc domed pistons is that + or - 5.8cc as mine are -1.5cc and I use a 44cc chamber but the engine would not make as much torque and power with a smaller cam profile than it's currently got

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    Re: N/A YB Build - RSA Build

    Dome at piston reduces the chamber volume, dish increases the chamber volume.

    In my opinion ( and I do not have much experience with the YBs ) YB needs a good CR ( at least around 11.8 if not 12.20 - 12.50 ) in combination with a perfect camshaft and headwork to produce some good torque and power. So, in my case, to be realistic my poor engine would not be able to produce more than 205 -210 bhp at most I think. I imagine, we really need 39 cc chamber if using 92 mm bore with 1mm headgasket.

    What camshaft combination are you using ?

    I am sure here in TS, there are very knowledgeable friends on n/a YB engines. Also, for some really good profiles it is really worth looking into Catcams YB profiles. As RWD fords rule mentioned there are 3 very nice profiles at Cat Cams.

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    Re: N/A YB Build - RSA Build

    There are two completely different ways of tuning this engine which also applies to any race or rally engine you can think of


    1. The old school way is to use cams with high duration 300 to 310*+, to get a Decent DCR figure and cylinder pressures the inlet cam needs to be greatly advanced and to use a very tight LSA around 102* even 100*, with massive valve lift at tdc, then you need massive valve reliefs to match which reduces the static compression needing further inlet cam advance to get a good DCR figure, with cams set up like this the exhaust valve opens later towards the end of the power stroke, in which case larger primaries are needed to make decent top end power

    This tuning method uses cams with big duration, moderate valve lift, very tight LSA's (due to the low static compression level vs the cam duration), very deep valve reliefs, large primaries, poor low rpm power and torque delivery below 3500rpm, good mid range and top end power, I am not saying this is a BAD tuning method, it is the most popular tuning method for race engines and can produce very good results with race engines where the rpm's are always kept above 3500rpm



    2. The newer way of tuning engines is to use more modern cam profiles with less seat timing, 280 to 295* seat (@.001" lift with lash), higher valve lift, increased upper lift duration, wider LSA, 105*+ (up to 112* with some engines), reduced overlap lift, shallower valve reliefs, higher static compression, the same DCR or higher, better low rpm power due to reduced overlap, smaller primaries, engine will pull right down to 2500rpm, smooth torque delivery, hard punch out of corners, much wider usable power band, when set up well will make higher peak power and much broader spread of torque, Much faster for rallying and if tuned well can dominate races too


    One thing effects another and another and it all has to work well together, especially for rallying the camshaft is the most critical engine tuning component of all, this is because the rpm's will often drop to 3000rpm and sometimes even 2500rpm, and will go right up to the rev limiter on the long straights and between gears, so we need the widest possible power band we can get, an engine with lots of overlap is dead out of corners, I see plenty of those, 6 speed sequential and throttle bodies are used as a band aid to cover up poorly spec'd cams

    Most racing is a lot less fussy imho, if the engine pulls well from 3.5 to 4k upwards that will do just fine

    If the engine CC has been greatly increased the LSA needs to be made tighter for best results, more duration can be a good thing and the more lift the better as always

    Giving my honest opinion going on what I have tested and observed which applies to any 4 stroke engine, it all depends on the application, obviously I am more interested in rally engines of course but a winning full on tarmac rally engine will also do very well in a race

    Have a good Xmas :santa:
    "Horsepower sells cars, torque wins races" - Enzo Ferrari

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