Andre3000 55 Report post Posted May 12, 2009 Im finally getting down to business with the performance mod side of things. Firstly: Im looking at getting a shrick 284 cam. Does anyone know of a place cheaper than ireland engineering? Secondly: Where to get 17lb injectors + fuel pump? And also whereabouts would i get my cam replaced? Has anyone had any good experiences? Any help/guidance is appreciated. Cheers Andrew Quote Share this post Link to post Share on other sites
antony 0 Report post Posted May 12, 2009 Not sure if there cheaper than IE, http://www.evo-s.co.uk Im running a 273/273 catcam in my 2.7. Runs really good, very driveable. Quote Share this post Link to post Share on other sites
Mark 178 Report post Posted May 12, 2009 Am in the process of doing this ATM. Not, with a performance cam... but having the stock cam refurbished. One thing I've learnt about the process, is that once you get the head off an M20 (especially one with decent k's on the clock), you find more and more things that need replacing. Mine started off with just needing to replace the head studs and cam. Now we're onto replacing exhaust guides, relapping valves, head skimming, new cambelt, waterpump and tensioner bearing etc etc. I'm having the work done at DCH motorsport, and for the original work of replacing the cam and head studs they quoted me 10 hours labour. The other thing you may need to look at is with a performance cam I believe you often need stiffer valve springs. Quote Share this post Link to post Share on other sites
CamB 48 Report post Posted May 12, 2009 (edited) Figure out what has 17lb injectors (I have no idea, sorry) - try a commodore if you want cheap. You should also figure out once and for all if a new cam needs new rockers. I chickened out and have ordered new rockers for the M10, but I am getting the Ireland engineering ones as I want the flexibility to rev a bit higher than M10 rockers will generally allow, so the new cam was a good excuse for new rockers... (edit) Good points above - my M10 head needed new valve guides and a skim, and I had all the valve springs tested and they are fine, although now I've ordered new ones (see above - higher revs). Schrick refers to valve springs as "optional" with the 284. Edited May 12, 2009 by CamB Quote Share this post Link to post Share on other sites
Andre3000 55 Report post Posted May 12, 2009 What i dont get is the dual cam watsit thingys. ie the 272/284? am i just reading it wrong? Spoke to steve from Motorsport Engineering about replacing the cam, and maybe the 288 would be the best option for more power/little loss? Im confusing myself already Quote Share this post Link to post Share on other sites
Driftit 2069 Report post Posted May 12, 2009 I was told by Gavin and Hi Velocity to not go higher than 282 for the M20B28 I may build. And I would require new hardend rockers and valve springs. Prob going oversized valves at the same time. What your thinking of doing will set you back more than 2K. You do realise this? Quote Share this post Link to post Share on other sites
CamB 48 Report post Posted May 12, 2009 The different numbers are difference intake and exhaust duration - an asymmetric cam. I **think** less exhaust duration means less overlap and more civilised at idle (ie what Dan says). Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted May 12, 2009 (edited) What your thinking of doing will set you back more than 2K. You do realise this? +1 You wont do it even for $2000 if your going to do it properly New cam or regrind Machine head, valves & new valve guides Rocker shafts ? Valve springs Rocker arms & accentrics Head bolt set Exhaust studs Gasket set Cambelt Tensioner Water pump Approx 10-12 hrs Labour Remap @ Gavins What is your budget to do this Andrew ??? Edited May 12, 2009 by *Glenn* Quote Share this post Link to post Share on other sites
Andrew 30 Report post Posted May 12, 2009 I was told by Gavin and Hi Velocity to not go higher than 282 for the M20B28 I may build. And I would require new hardend rockers and valve springs. Prob going oversized valves at the same time. He's right. That is exactly what I had to do to get power. I may have a set of spanking new injectors you can use (were a little large for my 3.1ltr) The head cost me over 4k and did everything on Glenn's list + oversize valves, port and polish and lots of flow testing. Quote Share this post Link to post Share on other sites
Driftit 2069 Report post Posted May 12, 2009 Hence why my 2.8 project is on hold at the moment. It is not the best bang for buck. Best bang for buck would be replacing the motor with a 1JZGTE. But I like the BMW M20. And wanted to stick to it. Quote Share this post Link to post Share on other sites
Guest FrantiC Report post Posted May 12, 2009 (edited) e36 325i m50 injectors.. 17.5lb's I used them in my m20 2.7 n/a Edited May 12, 2009 by FrantiC Quote Share this post Link to post Share on other sites
Andre3000 55 Report post Posted May 13, 2009 Yeah im hoping it would be no more than 3000. I'll come and see you tomorrow morning Glenn an talk about this in a bit more detail. I am aware that it will probably blow my budget, but im not too worried about that, these mods are long overdue. Id also be wanting to use a lightened flywheel too. If i was to use the 272/284 cam, would it be too much lift if i wanted to turbo/supercharge later on? Thanks for the input guys, its helping alot Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted May 13, 2009 (edited) Yeah im hoping it would be no more than 3000. I'll come and see you tomorrow morning Glenn an talk about this in a bit more detail. I am aware that it will probably blow my budget, but im not too worried about that, these mods are long overdue. Id also be wanting to use a lightened flywheel too. If i was to use the 272/284 cam, would it be too much lift if i wanted to turbo/supercharge later on? Thanks for the input guys, its helping alot I would say that its going to be an engine out job then, with clutch, flywheel, head off & the oil leaks you've got from the engine & the gearbox....remember the list I gave you ?? Turbo & SC dont need a cam as your achieving more air by forced induction rather that relying on NA which needs a cam to gain HP I think you had better decide what you are going to do in the future before you do anything at all Edited May 13, 2009 by *Glenn* Quote Share this post Link to post Share on other sites
CamB 48 Report post Posted May 13, 2009 However, if you design your turbo system for such a cam, you can make more power with less boost (at the expense of that power arriving later and some lag). Having said that, the standard cam with the right turbo choice (again, with a less restrictive exhaust) appears to be able to make 300hp plus ... how much powers do you need? Quote Share this post Link to post Share on other sites
tibbs.james 1 Report post Posted May 13, 2009 I would say that its going to be an engine out job then, with clutch, flywheel, head off & the oil leaks you've got from the engine & the gearbox....remember the list I gave you ?? Turbo & SC dont need a cam as your achieving more air by forced induction rather that relying on NA which needs a cam to gain HP I think you had better decide what you are going to do in the future before you do anything at all Once you get to this stage it would be recommended to do a freshen up of the bottom end another $1000 to get the basics right (Hone,Rings, & bearings & balance) is going to go a long way to making things better overall. Especially if you get so far on the cylinder head and spin a bearing / break a rod bolt, or end up with low compression on one cylinder. Quote Share this post Link to post Share on other sites
Silver Fox 43 Report post Posted May 13, 2009 The problem with only doing the head, is that you put more pressure on the bottom end , and it will go bad. Had this happen to two of my early rebuilds on the M40s. Now do both at the same time, not much more cost, but so much easier with the motor out once only. Quote Share this post Link to post Share on other sites
Guest FrantiC Report post Posted May 13, 2009 Once you get to this stage it would be recommended to do a freshen up of the bottom end another $1000 to get the basics right (Hone,Rings, & bearings & balance) is going to go a long way to making things better overall. Especially if you get so far on the cylinder head and spin a bearing / break a rod bolt, or end up with low compression on one cylinder. I agree. No point splashing out on one area of the motor, slapping on a fresh worked head onto a worn out bottom end. Do it once, Do it right! Quote Share this post Link to post Share on other sites
DRTDVL 0 Report post Posted May 13, 2009 If i was to use the 272/284 cam, would it be too much lift if i wanted to turbo/supercharge later on? Thanks for the input guys, its helping alot If your dead set on going down the forced induction route, then when your getting the head work done see if they can increase the EXHAUST port size... As the engine was designed with N/A application in mind manufactures create a smaller exhaust port comparied with the intake port. As the engine sucks the air in there can only be a theoritical max of 1 athmosphere of pressure (typically much less then this) when the engine draws in the air, but it's being forced out the engine at a pressurized rate. Depending on the manufacture you can see a exhaust port runner volume 70 - 80% (don't qoute me on those it's been years since i learnt this stuff might be closer to 80 - 85%) typically of the intake port runner volume. As your now by providing forced induction changing the purpose of the head and you could possiblely develop a bottleneck of the exhaust runner size being too small relative to the amount of air now entering the chamber via the intake. Not that it really matters as it's not a super high level race car - but i'm bored and in an informative mood... Quote Share this post Link to post Share on other sites
CamB 48 Report post Posted May 13, 2009 Not that it really matters as it's not a super high level race car - but i'm bored and in an informative mood... To back this up, my head had the exhaust ports modestly enlarged for turbo ---> it was suggested by the head guy. Quote Share this post Link to post Share on other sites
DRTDVL 0 Report post Posted May 13, 2009 (edited) Depending on who you talk to a 1:1 ratio is perfect so the exact amount of air entering the system will leave the system. Generally if your 85%+ of the intake size your doing very well... If you google you see all sorts of ratios floating around... I remember vaguely reading about a drag team in the states that found a exhaust port 48% smaller than the intake port worked for them... They where an all motor class team... Edited May 13, 2009 by DRTDVL Quote Share this post Link to post Share on other sites
