2.1 8v

Discussion in '8-valve' started by newkid, Jul 11, 2012.

  1. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

    Joined:
    Jul 26, 2006
    Likes Received:
    3,320
    Location:
    Creating Pfredstarke
    The hangover made you numb to the hail?...you're nuts...lol
     
  2. mr hillclimber Club GTI Supporter and Sponsor

    Joined:
    Nov 24, 2005
    Likes Received:
    148
    Location:
    Southwest
    As you like to quote me so accurately I'll gladly help brush off that chip on yr shoulder...

    Just for you yes I will explain...

    Yes I do have forced induction experience!...I was involved with a "lot" of Escort RS turbo work years ago...ZVH conversions etc. In pure and simple terms, stacked gaskets are a bodge!...usually carried out by people who think they now more than they do. Some of the local lads tried to do this on d.i.y ZVH conversions and regularly came in with poor running engines...pulling the heads off always would find the gasket"S" blown apart. Oddly enough, our conversions with 1 gasket, no spacer plates, and machined pistons worked fine.

    Another chap tried to do the same on a high c.r Mini (A series...done "lots" of those!)...guess what happened to those gaskets!

    Turbo engine's work mechanically on the same principle as any others...that's "mechanically"...i.e nothing to do with the forced induction side of it. Mitlom explained the basics perfectly so I don't need to go over it again....unless of course his uni lecturer didnt know what he was talking about. Big squish clearance's are bad...tight clearances are good...simple.

    I will concede that if the squish clearance is "increased" past a certain point...it varies from engine to engine...the issue goes into a safer zone...e.g Cosworth YB turbo (did a lot with those too!)...from memory the std clearance is around 35-40 thou...increasing past that results in detted pistons in high boost applications...drop past around 60-65 thou and its ok again to a point. Dished pistons are the correct way to lower the c.r, along with chamber mods if needed.

    A spacer plate is a slightly better way, at least a gasket either side stands a fighting chance of sealing against the flat surface either side of it...but it still increases the squish area way past the ideal...a spacer and two gaskets would certainly never be used to lower the c.r in an atmo engine...the piston crown would end up a mile away from the head.

    Here's an example...race spec Ford crossflow...Kent engine...high c.r can be used with a flat head and the pistons down the bore, so in effect the chamber is the gap between the piston crown & head face. The other way is with dished pistons and tight squish. Peak power both very similar, however the short piston engine needs 10 degree's more ignition timing to make the same power. Exhaust emissions are also poor in the big clearance engines, as is fuel consumption in road spec compared to the tighter squish versions.

    You make a complete contradiction in your own statement by saying lack of squish would not be a cause of detonation, yet can lead to poor combustion...and go on to say that increased squish clearance can lead to end gasses causing hot spots that can lead to detonation!...you'd make a great politician.

    You further go on to say that basically drowning the engine in fuel and knocking back ignition timing will take away the det issues...very true...to a point...but will also lead to increased fuel consumption and poor emissions...all unnecessary if an engine is built properly in the first place.

    Dont tell me...you've got stacked gaskets in your engine? If you and the rest of the turbo boys pull your pistons and have a deeper bowl machined in them to lower the c.r you'll save the cost of gaskets (I doubt a JDM/HKS gasket was cheap), use less fuel, and have a cleaner, more efficient running engine making more power which'll be an even better result for you.

    See, no need for you turbo/calibration boys to struggle anymore...you only got to ask nicely and us engine builders can help.

    You wanted some "supporting facts" as well...

    PWE...Honda 2ltr K20, 12:1 c.r, 1 bar supercharged boost, 580hp @ 9k
    SRD...European & UK stock car champion engine builder for 7 years running
    SB engines...Castle Coombe outright winners the last 2 years running
    JRE...countless race, rally, hotrod engine wins over 10 years
    JMR...3 hillclimb & sprint championships and counting

    Ask any of the above about squish clearance and I know what they'll tell you....tight as poss every time...I also know what they'll say about stacked gaskets.

    This too isnt personal...you've asked..I've answered.

    I'm also not going to continue flooding this mans post, apart from saying, the 2.1 can give decent results but it is one of a lot of effort for the small gains, it totally depends on how much you value the extra power or the challenge ahead...it's possible, but mill the pistons off to come 28 thou out the block and use an ABF head gasket @ 68 thou compressed thickness...the 40 thou clearance will work fine, and loosing the raised D section will give you better squish as you can then take advantage of both squish zone's on the head face. Lift @ tdc on the road cams are not a problem as the std chamber depth is around 8mm...you wont find a race cam lifting that much!...so as long as the valve doesnt go past the head face @ tdc it'll never touch the piston.
     
  3. fthaimike Forum Addict

    Joined:
    Oct 27, 2003
    Likes Received:
    12
    mine is a short block 1.8 bored out with a diesel crank and goes well enough for me and has run for many years though like poeople say they are an expensive mod.
     
  4. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

    Joined:
    Jul 26, 2006
    Likes Received:
    3,320
    Location:
    Creating Pfredstarke
    I was expecting a more in depth technical answer to my question, rather than sarcastic remarks plus suggesting I have a "chip on my shoulder"? I have no desire to attack anyone on here personally even though I may not always agree on a technical basis. You do not really know me face to face to make such assumptions and would be happy to talk about any concerns or perceptions you have about my comments on here or if you will like to know more about my personal life in a telephone conversation or any medium you are comfortable if needs be. We already know the typing thing is no good.

    The examples you qoute of stacked gasket failure still do not describe why others with different engines do not have any issues or concerns, let alone detonation or or engine failure. The examples of failures you quote do not make the practice "wrong". So I am not convinced and neither do we turbo boys have an issue as you seem to suggest right up to 915bhp and beyond. In my own case I am yet to have the 2 MLS gaskets my turbo'd ABF fail in the 16000miles of service I have had out of the engine.

    As I and others have said in this case for Newkid, I would not agree to carry out such a modification of stacking gaskets on an engine such as this "2.1" as that would not be well thought out and have already suggested milling the piston and use with the MLS gasket.

    But then there are the user's expectations which perhaps may be satisfied by taking the exisiting engine and remapping to increase torque. An standalone engine controller of the owner's choice can be used to control the engine to carryout the task.

    Kind regards.
     
    Last edited: Jul 14, 2012
  5. tshirt2k

    tshirt2k Forum Junkie

    Joined:
    Oct 21, 2004
    Likes Received:
    325
    Location:
    Herts
    Mr Hillclimer. Thanks for enlightening me, I better scrap my "stacked Gasket" Bodged turbo engine then, and go down your route.

    But hold up! There seems to be nothing "wrong" with it! :o. 260ftlb and 250hp doesnt seem bodged to me and still returns good fuel economy AND the mrs can drive it to the shops. 13,000 miles on my bodged engine can't be bad! Unless its all in the mapping?

    Seems to me, from how you write, that you may need to brush that french fry off your shoulder. Maybe you should try to communicate with people and find out what they are really like, instead of assuming you know them. Its not a willy waving competition. A bit childish and insecure if you ask me :(
     
  6. fthaimike Forum Addict

    Joined:
    Oct 27, 2003
    Likes Received:
    12
    Read post #11 again, on 1st glance that can be taken the wrong way ;)
     
  7. tones61

    tones61 Forum Member

    Joined:
    Dec 27, 2007
    Likes Received:
    12
    Location:
    ~ MOT TESTING ~ plymouth
  8. Admin Guest

    You don't even need to mill the pistons, 8v ones are meant to fit under a valver head and lower the comp enough without any mods?! So, don't 2.1 it, turn in into a 16v turbo.

    If you mill a bowl into the centre on a piston are you not going to get bastyy hot spots appearing around the edges were the clearance is less? Would it be best to just mill a flat layer of the piston? Something that I have always wondered about anyway?
     
  9. tones61

    tones61 Forum Member

    Joined:
    Dec 27, 2007
    Likes Received:
    12
    Location:
    ~ MOT TESTING ~ plymouth
  10. tones61

    tones61 Forum Member

    Joined:
    Dec 27, 2007
    Likes Received:
    12
    Location:
    ~ MOT TESTING ~ plymouth
    all this 'chip' brushing is making me hungry,lol ;)
     
  11. stytrhe Forum Member

    Joined:
    Jul 6, 2005
    Likes Received:
    3
    Location:
    United Kingdom
    Hi, Im currently getting some parts together to make a 2.1 8v engine. Ive got a PB 1.8 block coming, I've bought a 1Y diesel crank, and I've all ready got a tsr pack C head on the current engine. Ive got a few questions if anyone is able to help.

    1. What sort of machining has to be done to the engine block, I assume some work to the crank so it does hit anything. Also a rebore to 83.5 I believe ?
    2. Is there any point in getting forged pistons & rods as its going to be an NA engine.
    3. I guessing I'm going to have to increase the fueling, so bigger injectors, higher pressure fuel pump, and new engine management. See what have people used on theirs.
    4. Also I'm assuming I need a bigger/heavy duty clutch, the car all ready has a diesel gearbox in, which I'm going to have rebuilt.

    Thanks for any advise people can give.
    Ross
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice