Announcement

Collapse
No announcement yet.

BP Motoriety

Collapse
X
Collapse
 
  • Page of 4
  • Filter
  • Time
  • Show
Clear All
new posts
Previous 1 2 3 4 template Next
    #1

    BP Motoriety

    I've come across a few interesting differences in BP motors (some of which are fairly well-known):

    i took the crank out of a 94 Escort GT at the junkyard yesterday and guess what?? no MBSP. everything else was the same: oil pan, oil squirters (1st time seeing them up close - pretty cool ) and the main bearing caps even had the bolt holes for the MBSP. Jess with a 95 turbo GT also posted on the miataforum that his BP didn't have a MBSP.....
    the reason for wanting the crank was 1) to see if it was a big-nose and 2) i wondered if it was forged. not sure yet on the big-nose part but it definitely appears to be forged (based on the *wide* 'seam' that is noticeable running along the crank). the thing was HEAVY too - man it almost seems like its half of the short block's weight!!

    i have a 91 Escort GT long block that i will soon be tearing apart. it'll be interesting to see 1) if the crank is forged and 2) if it has a MBSP. my guess/hope is yes on both counts....

    there is definitely some confusion out there - as i've read on the miataforum that the official word from mazda is that ALL BP 1.8 cranks are forged. the 'mazda answer', though, may have just related to the *miata* BP.....
    2 members over there have stated that they've seen Escort GT cranks that are (apparently) *cast*. another very reputable member has stated that all BP DOHC motors had forged cranks - including Mazda, Ford, and Kia. he said the ONLY *cast* BP crank came in the SOHC motor of the 90-4 Protege DX

    ????

    on another note, a guy on protegeclub recently installed the *factory header* on his 1st gen pro. he talked to his local mazda dealer and they told him that the factory header was put only on the automatic-equipped '94 (of course all 2nd gen BP's have it).
    at this same junkyard yesterday, i came across a 94 5spd LX with a 10/93 build date. it had the factory header.....

    never believe what you hear from the dealer

    i'll post some other stuff later.
    if anyone else with a BP powered FWD car (including Kia) wants to post their findings, i'd be interested.
    Last edited by naprotejay; 06-18-2004, 08:54 PM.
    Original owner: 1991 Protege LX (now w/SOHC) and a few more BG's ....
    Tags: None
    #2
    90-91 BP's in the protege's had casted cranks.

    iirc the 1.8 sohc (92+) had a forged crank that will swap into a dohc.
    When you turn your car on... does it return the favor?

    Originally posted by goldstar
    Yes, still have it. It was my attempt to immortalize you in verse.

    A Protege driver named Brock
    Once said 7 seconds he'd clock.
    So his engine he goosed
    With much too much boost,
    And drove a rod through his block.

    Comment

      #3
      hmmm interesting; so you're basically saying that ALL the *early* 90-1? BP's (SOHC or DOHC) came with cast cranks. then, sometime in 92, ALL BP's (including SOHC) came with forged cranks......
      Last edited by naprotejay; 06-18-2004, 02:33 AM.
      Original owner: 1991 Protege LX (now w/SOHC) and a few more BG's ....

      Comment

        #4
        if memory serves me right

        yes
        When you turn your car on... does it return the favor?

        Originally posted by goldstar
        Yes, still have it. It was my attempt to immortalize you in verse.

        A Protege driver named Brock
        Once said 7 seconds he'd clock.
        So his engine he goosed
        With much too much boost,
        And drove a rod through his block.

        Comment

          #5
          how about internals, what year was the compression ratio swap? Ect, ect we might as well post most of the info here
          00 dakota 4x4
          90 crx si - ls/vtec

          Comment

            #6
            the 90 - 94 SOHC has a 8.9:1 compression
            the 90-94 dohc has a 9:1 compression
            sohc internals on a dohc head will yield a 8.2:1 compression

            B6-DET connecting rods will fit in a BP DET and are stronger than the ones found in the GTX.
            When you turn your car on... does it return the favor?

            Originally posted by goldstar
            Yes, still have it. It was my attempt to immortalize you in verse.

            A Protege driver named Brock
            Once said 7 seconds he'd clock.
            So his engine he goosed
            With much too much boost,
            And drove a rod through his block.

            Comment

              #7
              According to this page:
              http://members.aol.com/solomiata/MX5Engine.html

              The earlier BPs actually had a 8.8:1 compression ratio, at least in Miatas.
              2006 Mazda 3 hatchback manual

              Comment

                #8
                i think that would be due to a difference in the head more specifically the combustion chamber
                When you turn your car on... does it return the favor?

                Originally posted by goldstar
                Yes, still have it. It was my attempt to immortalize you in verse.

                A Protege driver named Brock
                Once said 7 seconds he'd clock.
                So his engine he goosed
                With much too much boost,
                And drove a rod through his block.

                Comment

                  #9
                  Originally posted by TheMAN
                  the B6 turbo rods are the same as the BP's

                  the stronger rods are the GTR rods
                  i have read differently. but whatever, the important part is that they fit in the BP
                  When you turn your car on... does it return the favor?

                  Originally posted by goldstar
                  Yes, still have it. It was my attempt to immortalize you in verse.

                  A Protege driver named Brock
                  Once said 7 seconds he'd clock.
                  So his engine he goosed
                  With much too much boost,
                  And drove a rod through his block.

                  Comment

                    #10
                    Ya, the MBSPs are something awesome. They have a rare type of Torx bolt, but a double hex will work just fine. My crank has ZERO freeplay, something I thought was cool. All parts were within spec(cams, journals etc), most of which are still ideal tolorances.

                    Comment

                      #11
                      its getting clearer :

                      i went back to the junkyard today and ran into a miataforum member whom i've met before. anyway he was there to get the crank that i pulled just 2 days ago.... so seeing as how the crank was no longer there, he decided to pull apart a 91 Escort GT motor ( with a ?/90 build date). i took a look at the crank. it was a short-nose, AND it was cast (the 'seam' that runs along the crank is only a few mm's wide), AND it had no MBSP.....

                      so, i've come to these basic conclusions (keep in mind they are NOT 'definites' ) :

                      1) no Ford based BP's came with the MBSP (except maybe the OBDII 95 1/2 - 96 EGT ??).
                      2) all Mazda protege BP's (including the SOHC) came with the MBSP. i have NEVER heard of the protege BP DOHC or SOHC not having one...
                      3) the short-nose BP crank is cast (just like the B6 crank). this is the case whether its Ford or Mazda.
                      4) the big-nose BP crank (which came on ALL miatas and at some point on all protege/escorts) is forged.

                      now #3 is one i'm not as sure about (alto it agrees with Brock - no offense)..... could it be that Protege short-nose BP DOHC's came with a forged crank? and the short-nose SOHC came with a cast crank?? this would agree with RandyS' s findings.....

                      here's one of the details to note to see whether you have the short-nose or big-nose:
                      when you take the oil pan off, look at the bottom of the oil pump - if it has 'B6' on it i'm fairly sure its a short-nose.

                      one reason i went back to the junkyard today is to get the oil pump from the 94 EGT BP motor from which i pulled the crank. it DOES NOT have 'B6' on the bottom; in fact it has nothing written on the bottom. the 91 EGT oil pump did. also its easy to see a casting difference between the 'B6' oil pump and the 'un-marked' 94 BP oil pump.

                      anyway i now have a big-nose forged BP crank and its corresponding oil pump. i plan on using it in the 91 EGT long-block i have - which i'm now 99.9 percent sure has a cast crank and no MBSP. i'll probably see if i can find a SOHC pro, pull the oil pan and grab the MBSP.

                      how valuable is the MBSP? how necessary is the forged crank?? how vulnerable to crank snout failure is the short-nose BP??? i personally would rather have all the GOOD parts; but as an example, my short-nose BP has lasted 224K miles and several timing belt changes with no problems..... it definitely does seem that the short-nose BP doesn't have the same tendency to fail as does the short-nose B6.
                      Last edited by naprotejay; 06-18-2004, 11:23 PM.
                      Original owner: 1991 Protege LX (now w/SOHC) and a few more BG's ....

                      Comment

                        #12
                        stupid question: what's an mbsp?

                        Comment

                          #13
                          Originally posted by 95ProLeila
                          stupid question: what's an mbsp?
                          M(ain) B(earing) S(upport) P(late)

                          its a metal 'plate' that bolts to the main bearing caps. it stiffens the bottom end by tying all the main bearings together - much like Darryl's front lower tie bar connects the lower control arms together which otherwise are just hanging out in space....

                          and bty it could partly be the reason why the BP short-nose doesn't suffer from crank snout failure as does the short-nose B6 (which didn't have a MBSP).
                          of course this doesn't explain why short-nose BP EGT's don't suffer from crank snout failure.......
                          Last edited by naprotejay; 06-18-2004, 10:13 PM.
                          Original owner: 1991 Protege LX (now w/SOHC) and a few more BG's ....

                          Comment

                            #14
                            Thanks for the explanation.

                            Comment

                              #15
                              word....good info
                              93' Noble Green MX-ZE (sold )
                              02' Graphite Grey WRX Stage 4, 286whp
                              05' Pontiac Vibe daily driver, lowered/tinted/rims

                              Comment

                              Previous 1 2 3 4 template Next
                              Working...
                              X