Asad Posted August 4, 2012 Share Posted August 4, 2012 Basically....power goal ~250bhpspec:4efe block + crankstock 4efte GT rods74.5mm ross pistons6500-6800 rpm rev limitgt25 at 1-1.2 bar external wgemb/emudiy ported headacis manifoldjust to clarify and put the ommm you need to go fully forged bandwagon to bed, yes i can get forged rods but im on a tight budget and my power goal is fixed...this is just a "slightly better than standard build with tweeks"a standard engine is out of the question people want an arm n a leg and god only knows what condition it will be in....if i was to forge id go 5E je pistons/pauter rods/arp studs top and bottom/gtx turbo/clevite77 bearings...not to mention the gearbox issues id inevitably face @300+ bhp so throw in another £2-3k for a zisco gearset ....so no lets not go there :surrender:now to make sure everythings reliable i need to run a low compression ratio to take stress off the rods hence the lower rev limit....anyone got any suggestions as to a good compression ratio? ive read that HYBRID on tgtt has sucessfully ran 1.5-1.7 bar on standard rods with a cr of 7.34:1how do i go about calculating what i need? what would be best? Quote Link to post Share on other sites
klyfax Posted August 5, 2012 Share Posted August 5, 2012 4efe block + crankstock 4efte GT rods.74mm piston can work great if the engine is not worn. Check that and save the money. Aim for stock compression - camshaft are build for it.Go 7200 rpm. Engine is build for it.GT25 at 1-1.2 bar external wg sounds great.emb/emu - whats that?Match port both manifolds to top, leave the rest. You might do more harm then good.acis manifold, if you already have it, or can find it with a very low cost, mount it. Else leave it standard.Get a Greddy ECU system or something that can control fuel and ignition. Its here the durability of the engine is.Target 250 bhp @ 1.2 bar. Have always worked here in Denmark. And still going... Quote Link to post Share on other sites
AdamB Posted August 5, 2012 Share Posted August 5, 2012 (edited) You will be fine at stock compression ratio mate, but if its going for a rebuild you can always chuck in a thicker metal headgasket like a 1.2mm.It's not the rods that are the problem, its the weak piston ringlands, and since you would have rectified this problem you'll be good to go mate. Just make sure to run some good bottom end bearing shells ;) Also I wouldn't bother touching the head, just clean out all the carbon shit from it and leave it at that Edited August 5, 2012 by AdamB Quote Link to post Share on other sites
Asad Posted August 5, 2012 Author Share Posted August 5, 2012 Cheers lads thats a load off my mind, may go with your suggestion n throw a thicker hg on...any idea what the cr would be after the head and block is skimmed + a 1.9mm hg?Bearings id go for acl or clevites..as for the head id just be cleaning the casting marks roughly/port matching mabe even cut the valve guides down but thats it no removal of excess material @ klyfaxthe reason i want a rebore is to start fresh, so 74.5mm should suffice..emb is emanage blue n emu is emanage ultimate....decided on a ngk wideband and some stack/omori gauges but yet to finalise management When you say port match the top, do you mean just the top half of the port and leave like a step in both inlet+exhaust manifolds? Ive read that having a step in the exhaust manifold-head is a good thing something called exhaust reversion? I have a acis ready to go...a run on each set of runners will easily determine the best open pointApreciate the help guys Quote Link to post Share on other sites
AdamB Posted August 5, 2012 Share Posted August 5, 2012 (edited) You want the intake manifold runners to be slightly smaller than the cylinder head ports, this is to increase air velocity as it enters the cylinder head.The reverse for the exhaust side, its good to have a manifold with larger ports than that of the cylinder head as this reduces back pressure.So as for port matching, I would go with the above style setup I wouldn't recommend running a 1.9mm tbh, it will make the car very lazy off boost, and since the 1.3 doesn't have a great deal of torque either you will only be going backwords. I wouldn't go no more than a 1.4mm headgasket.The problem lies with the mapper in my opinion, you could run a complete stock setup and easily make 250bhp, the problem is mappers want to induce as much ignition timing into the map as possible, but as soon as det occurs they reduce the timing. This is wrong, you need to understand what causes detonation and that is excessive cylinder pressure, ie sparking at the wrong time! The way to combat this is to retard the valve timing, but since this is time consuming, tuners don't do this. Retarding the valve timing reduces cylinder pressure, you want to keep as much ignition timing in the map as possible!The main problem with the E series engine is that valve timing is NOT able to be independently adjusted between intake and exhaust, since these engines are not a true twin cam design. Edited August 5, 2012 by AdamB Quote Link to post Share on other sites
Asad Posted August 5, 2012 Author Share Posted August 5, 2012 Ahh right so it would be best to port the inlet ports to a gasket and leave the intet ports alone vice versa for the exhaust...Athena have loads of different sizes avaliable so ill pick one say 1-1.2mm? tbh thats now my main concern, i dont want to invest in a solid engine and have a tuner half ass things and not make the best of what i have given him..having looked at the td04's at 1bar id be expecting nearer 250 with the gt25 and for it to hit full boost earlier....seems all the tuners tune the way u mention :/ Quote Link to post Share on other sites
AdamB Posted August 6, 2012 Share Posted August 6, 2012 (edited) You could gasket match the ports, and if funds allow get a 3 angle valve cut on the valve seats, this will allow a much better flow into and out of the head. I wouldn't then bother going with anymore modifications the head as it will perfectly fine at the boost pressure you plan on running, and even slightly more.I would go for a 1.2-1.4mm gasket, if you was going for a standalone system you could run thinner with ease due to the extra control, but since this is not the case I wouldn't advise it. I would try and stick around the stock 8.2:1 ratio, its quite a low ratio to begin with compared to modern turbocharged engines.What GT25 are you looking at? As I know there a few different varients in trim. But they should all be much more efficient than a td04 at around 1-1.1 bar of boost, although from what i've seen the gt25 seems to tail off top end quite a lot compared to the td04. But the GT25 will be a hell of a lot more reliable, the only problem is the expense if it goes wrong, as long as its well looked after you shouldn't see any problems The main reason why a lot of tuners reduce ignition timing is because its easy, quick, and they can get the job in and out in a faster time. If it was my business, I would ensure that the engine runs to the best ability that it could, if it means spending an extra day or so to work on, i'm sure my customer would be happier with a car that has 10 more bhp and 30 ft/lbs of torque more just by spending extra time on it. The problem lies with the customer mainly though, how much can you afford to spend on dyno time? If it was a race engine then my previous post stands true, trying to gain every last horsepower.But hey, what do I know, i'm not a tuner, I'm a student engine designer ;) Edited August 6, 2012 by AdamB Quote Link to post Share on other sites
Asad Posted August 9, 2012 Author Share Posted August 9, 2012 If i can ill get a 3 angle job but more than likely ill just lap them in, port match and give it a clean up at bestIm not sure on the management side tbh, im using 4efe hardwear/looms/ecu so i dont have a clue how im going to run it in as the 4efe ecu cant handle boost...do i run it in as NA then plug in a emb/emu and the turbo and go for a remap or?? Im doing a quick run in say 50miles not the million mile hype most do...Ive got someone looking for a gt25 variant for me as we speak, decided on a max pressure of 1.3bar so it should be fun across the rev range....ill update on what i get...I see where you coming from, i know what id do if i had the knowledge...Not chosen a mapper yet as everyones got a story to tell good and bad and due to the nature of the build im not sure who to take it to....Much apreciated Quote Link to post Share on other sites
AdamB Posted August 9, 2012 Share Posted August 9, 2012 The only thing I can think of is if the stock 4efe ecu will be able to recognise a 2 bar map sensor, like that of a stock gt/glanza. If you can get that to work all you would need is to run a fpr, raise the fuel pressure and run it in safely, or if you got an AFR gauge you can get it more accurate, but obviously wouldn't advise going balls out without having it checked atleast on an AFR gauge.You would be best to run the turbo from the outset as it will put load on the rings and bearings to bed them in. Otherwise when boost hits them they will get a shock lol.I looked at the GT25 only a few days ago, and I think its the larger trim which is better suited (GT2560) with a .48 turbine housing would go really well!Are you going to be building it yourself? Quote Link to post Share on other sites
Asad Posted August 9, 2012 Author Share Posted August 9, 2012 I know the stock map sensor doesnt read boost and im assuming the 4efte one has extra pins/wont fit...ill have a wideband im worried it will just all go crazy timing wise...theres no knock sensor eitherYeah im building it myself, using a 4efe block/crank going to measure it all up before/as im taking it apart and hopefully the crank is ok to go (end play/out of round/clearances)...dont like the idea of taking meat off the crank... Quote Link to post Share on other sites
AdamB Posted August 10, 2012 Share Posted August 10, 2012 (edited) Argh no knock sensor is a problem.Will the stock FTE ecu mate up with the EFE wiring loom plugs?In all honesty, without running a knock sensor is asking for trouble even with a tuned ecu. The ecu would need to be setup for various different intake temps, this alone will cost a lot of money in tuning time. Without a knock sensor EFI is pretty much useless imo, might as well run carbs.Does the block have a fitting for the knock sensor or is it just a case of the wiring loom doesn't have it featued?If its a case of the wiring is not featured it would be more beneficial to swap the loom over to an FTE one. Edited August 10, 2012 by AdamB Quote Link to post Share on other sites
Asad Posted August 10, 2012 Author Share Posted August 10, 2012 Tbh from the advice ive got from other members/yourself its probably best if i run a fte loom/ecu/sensors and tap the knock sensor into the block....run it in on say 0.5bar and then go get it mapped on a emu that way all i have to do set the fuel pressure as stock and monitor the afr till shes broken in Quote Link to post Share on other sites
AdamB Posted August 10, 2012 Share Posted August 10, 2012 That would be the best way mate, you wouldn't wanna waste or ruin an expensive engine. Quote Link to post Share on other sites
Asad Posted August 10, 2012 Author Share Posted August 10, 2012 Any idea on which running in oil to use? i know synthetic is a no go till 500miles and plenty of changes later..Apreciate the help, hows your build going by the way? Quote Link to post Share on other sites
AdamB Posted August 12, 2012 Share Posted August 12, 2012 (edited) Millers do a "running in" oil, I've used it before and done the job ok and had no problems. Just down to personal preference really as everyone tends to use a different brand.http://www.opieoils.co.uk/p-60229-millers-oils-cro-10w-40-competition-running-in-oil.aspxLooks as though its been packaged different to when I used it a few years ago, used to come in a blue tub lol. Ah it's not too bad, going slowly but getting there lol. Just need a turbo and clutch then I can start building the motor. Was going to go for the ECC twin plate but after they released the price the other day and I nearly vomited all over my laptop I think I may steer clear Edited August 12, 2012 by AdamB Quote Link to post Share on other sites
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