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Removal of front exhaust header - without moving right side fuel tank

Discussion in '308/328' started by GordonC, Dec 5, 2020.

  1. GordonC

    GordonC F1 Rookie
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    Aug 28, 2005
    3,821
    Calgary, AB, Canada
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    Gordon
    #1 GordonC, Dec 5, 2020
    Last edited: Dec 5, 2020
    (Prelude) when I bought my 308 in 2013, I started a maintenance thread here: Bought an 84 Euro 308 GTS QV today (July 2013) - now a maintenance thread. I kept that up through 2016, but haven't updated it since. Someday I'll catch up on the work I've done since then! I'm in the middle of a maintenance cycle right now, doing timing belts and tensioner pulleys, and will be installing an XDI ignition system from Nicks shortly.

    There's a fair sized list of "while I'm in there" tasks, and one of those is to install the front Tubi header. I installed the rear header in late 2014 after the original cracked on the #3 primary tube, but the front header was fine - and given the difficulty of accessing it, I decided to leave it until I was doing something which would get me part way into that job. 6 years later, to install the crank trigger wheel for the ignition, I needed to be half way to a timing belt job, so I did the belts. Doing the belts got me 3/4 of the way to the front header, so I decided to finally finish the other half of the header install.

    Here's my workspace - car is on a 4 post lift, I wouldn't tackle this job without the lift. The back of the car is supported by jack stands in a jack tray.

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    (Sidebar) Of course, installing the front header means removing the dipstick tube - so since I had to remove the dipstick tube, I did the other task that goes with removing the dipstick tube - dropping the oil sump pan, install the sump baffle, then re-install the sump pan with Stat-o-seal washers and nyloc nuts, to eliminate oil seeping down the sump pan studs. (While cleaning the inner bottom of the sump pan, I found a 6mm washer in the sludge - some prior mechanic must have dropped it down an oil galley in one of the heads!)

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    Back to the header removal - I read all the threads I could find here, and almost exclusively they all said: "Remove the right front fuel tank to take the front header out. Maybe lift the front of the engine an inch or so also, but you must move the fuel tank." I think Steve Magnusson was the only dissenting opinion, and he said "I've taken out the front header without moving the fuel tank - well, I'm 50% certain I did" ;) (paraphrasing). Based on that snippet, I decided to see if I could remove the front header without moving the fuel tank - I replaced all the fuel hoses 6 years ago, they're dry, and I prefer not having to open up the hose connections if I don't absolutely need to.

    Well, I'm happy to report that I was able to remove the front header without touching the right side fuel tank (or the left). Hopefully I'm not premature in reporting this, I haven't put the Tubi header back in yet!

    Starting point - photo through the right wheel well, timing belt covers off, new timing belts and tensioner pulleys already installed. Coolant pipe is still connected at the lower end.

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    I removed the coolant pipe, then took off the alternator, by taking off the bracket by the crank pulley (3 nuts on studs). With the main bracket loose, I could pivot the alternator to access the 4 nuts holding on the heat shield cover at the back, took off the back cover, and unfastened the two wires, freeing the alternator to come out. I make a point of cleaning the parts that come off as I go along, so they're ready to go back in when I start re-assembly.

    As the alternator parts came off - there still seems to have been a bit of oil leaking and getting distributed around the front right engine bay:
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    And then ready to re-install (but I will turn around the large bolt on the bracket first - the factory install of the bolt from the back makes it impossible to remove in situ if you want the alternator out without removing the bracket. Turn the bolt around to it goes in from the front, and the alternator can be separated from the bracket while the bracket remains mounted)

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    With the alternator removed, here's the space where the header has to come out:

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    Next step, removing the heat shield that covers the header collector. One bracket that connects to the forward side of the alternator was already free; the other two brackets are below the oil pump and on the front right engine mount.

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    When I cleaned up the heat shield, I discovered 3 small cracks, 2 on the top layer and 1 on the underside layer:

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    I drilled a crack-stop hole at the end of each crack, and will monitor the shield in a while to see if that's halted the cracks.

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    Now with the header collector heat shield out of the way:

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    Access to the dipstick tube is really easy with the alternator and heat shield and timing belt cover out of the way!

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    27mm wrench on the top tube fitting, 24mm wrench on the bottom fitting. These pictures were before I did the sump pan work, I removed the dipstick sump tube insert immediately following this picture:

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    From that point, it was time to remove the nuts on the header flange. It was easy enough to remove from underneath, reaching in from the right wheel well, both nuts on the #7 and #8 primary tubes, and even the closer nut on the #6 primary tube. After that it got much trickier! (I had already removed the front bulkhead heat shield)

    Looking from below the front of the engine compartment, this is the view looking up towards the left nut on the #5 primary tube - there's about a 4" gap between the clutch cable and main power wire from the battery to the starter to reach between.

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    Ultimately after a lot of trial and error, this is the rig I used to break free the nuts on the #5 and #6 primary tubes - 3/8" flex head ratchet, 2 ft long 3/8 extension, 3" long 3/8 extension, a 3/8 - 1/2" converter, and then a 13mm combination wrench. The combination wrench actually played the role of custom extended crowsfoot wrench Image Unavailable, Please Login . The 12 pt ring end went over the 13mm nut, and the 13mm open end was the perfect size to hold the 1/2" post end of the adapter!

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    I posted the picture of the view from the access point under the chassis; here's a bad picture taken by holding the phone up in the 4" gap between the header and the bulkhead to take a picture of the flange from just over the header tubes. The '1' is pointing to the right low side nut on the #5 tube; the '2' is pointing to the right low side on the #6 cylinder primary tube.

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    Again looking from below, here's the modified crowsfoot wrench Image Unavailable, Please Login with the ring end on the #6 lower nut, and the open end just visible along the line of sight that the 2 ft extension went up:

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    With all the nuts removed from the studs, the header comes away from the cylinder head - with a generous mm or 2 clearance from the studs before it contacts other bits.

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    At this stage, I couldn't move the header much at all, not even away from the studs for the flange, so decided that I needed the extra clearance provided by lifting the front of the engine by even 1/2". To lift just the front of the engine, the rear engine mounts aren't touched, but the top engine brace from the rear cam cover to the rear bulkhead must be disconnected at one end.

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    I used a bridge jack, pushed right up next to the jack tray, to support under the engine sump pan so I could undo the front engine mounts.

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    After undoing the main large bolts on the underside of the two front engine mounts, I had a look at the header again where it was going to have to come out:

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    And decided that it wasn't the fuel tank that was in the way of the header removal, it was the right side engine mount! Off came the grimy engine mount 0 and with it came the discovery of where the oil was coming from that coated that corner of the engine bay. As I loosened the mount bracket that attached to the engine block, several teaspoons (~10 ml? I don't know the correct teaspoons to millilitres conversion factor) came drooling out the bottom! Behind the mount bracket was the cleanest part of the entire engine block - with a high sludge mark to show where oil had accumulated behind the bracket.

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    I am guessing that oil was seeping out from the lower dipstick fitting, and then behind the mount bracket to this space - and from there, was seeping out to the mount and getting distributed around that corner by airflow.

    Engine mount and bracket hardware as it came off:

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    Cleaned up, original mount to the right of the picture, new engine mount on the left side. (That's another of those tasks that was waiting for the right collective of tasks to make it worthwhile - install new engine mounts.) I'll install all new lock washers, one of them broke when I was cleaning it!

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    At the bottom of that picture are a large nyloc nut and a small spring washer - neither is part of the engine mount assembly, they were trapped in the grime on top of the mount. At some point prior to my ownership, a mechanic must have dropped them into the darkness, and when they didn't fall through to the ground just left them wherever. Maybe the same mechanic who dropped the washer inside the engine.

    With the right front engine mount removedand the front of the engine raised by barely 1/2", this was now what I had to work with for the header removal - and probably the part you were waiting for in this thread. The key in this photo is the empty space where the engine mount used to be:

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    The first step to wrangle the header out of that space was to rotate the twin collector pipes about 75* clockwise:

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    Second step, angle the twin collector pipes towards the wheel well and work towards the rearward corner of the fuel tank. You can see how the two collector pipes are right next to the block, in the space that used to be occupied by the engine mount:

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    Coming through!

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    With the front header out of the way, this is the view to the front side of the engine compartment

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    Here's a wide angle view of the front (side) of the transverse engine, with the header out.

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    New and old headers together:

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    Before I put the Tubi header in, I have to clean up the front side of the engine block; install a power wire for the XDI system off the starter; and replace the hose from the air/oil separator, behind the starter, to the block drain.

    So key points to remove the front header without disturbing the fuel tank (for a Euro QV - headers are different on a USA QV, different on Euro or USA 2V, so I don't know if this would work on anything but a Euro QV)
    - remove AC compressor, timing belt cover on 5-8 bank
    - remove alternator and alternator bracket
    - remove header collector heat shield
    - remove dipstick tube
    - remove header flange nuts, ease header flange off the exhaust port studs
    - remove front engine mount bottom bolts
    - lift front of engine just a bit, 1/2" is enough, support the engine sump pan
    - remove right front engine mount and bracket entirely
    - rotate the header collector upwards to about 75* from horizontal - this will move the header flange forward and down from the exhaust port studs. The end of the header collector will be just beside the water pump pulley.
    - work the header in that orientation around the front of the engine towards the wheel well, the tight spot will be the corner of the collector pipes against the fuel tank.

    (If I can't get the Tubi header back in this way tomorrow, I'll come back and delete this thread! ;) )

    Cheers,
    Gordon
     
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  3. miketuason

    miketuason F1 World Champ
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    Mike
  4. dave80gtsi

    dave80gtsi Formula 3
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    Dave Meredith
    Wow.

    Good work, but in my case I found that removing the right side fuel tank was the Path Of Least Resistance. Once it was removed (easy), I had -plenty- of room to extract the front header w/o the need for all of the gymnastics.

    Still, saying that, please do update the thread once you finish the aftermarket header install ( ... curious as to why you've seen the need to replace the OEM's in the first place ... ), as I've never, ever had a case where a set of aftermarket headers fit perfectly.

    DM
     
  5. GordonC

    GordonC F1 Rookie
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    Aug 28, 2005
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    Calgary, AB, Canada
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    Gordon
    The replacement was required because the OEM rear header pretty much fell apart. I had a separate thread about it back in 2014: https://www.ferrarichat.com/forum/threads/308qv-manifold-leak-cracked-header.461379/

    Right after I finished a 30K major I did a quick road trip to Winnipeg (850 miles from Calgary), and on the return the engine started sounding really awful. The long story is in the thread, but the short story is that the OEM header had been hack-welded a few times before my ownership, and the #2 primary tube cracked entirely around, about 1" from the flange.

    [​IMG]

    When I got that OEM header out, it was obvious it wasn't worth trying to weld again - here's the previous weld jobs highlighted:

    [​IMG]

    I bought the Tubi header set at a GREAT price from T Rutlands, and installed the rear header at the time. Since the front OEM header was fine, and I'd just finished the belt change etc, I decided to leave the front header replacement until I was going back in for other tasks (which is now). While the front OEM header shows no issues and no evidence of hack re-welding, I just figured that it was best to have the headers matching, rather than a mismatch of Tubi rear and OEM front.

    As for fit of the aftermarket Tubi headers - they're like works of art! Amazing build quality, perfect welds, and the cast flange is gorgeous. The rear Tubi header fit perfectly:

    [​IMG]

    [​IMG]

    I'm keeping my fingers crossed that the front Tubi fits just as well. I will update this thread!
     
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  6. GordonC

    GordonC F1 Rookie
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    Aug 28, 2005
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    Calgary, AB, Canada
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    Gordon
    Well, that was a surprise - the new Tubi front header literally fell into place! Seriously, it dropped in, there was an inch clearance in every direction to insert it past the right fuel tank.

    Here's the front of the engine, cleaned up and ready to get the new header. I replaced the drain hose from the air/oil separator, and added a wire to the starter lug to power the XDI ignition - both tasks would have been much harder with a header in place:
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    The Tubi perched on the frame rail, ready to go in - note the end of the collector is outboard of the suspension spring:

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    6" further, collector is now inboard of the spring. The exhaust port flange and #8 primary tube is clear of the fuel tank. There was plenty of clearance all around, I only paused at this point for a photo:

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    That's the point where it just dropped in, with a clang of the primary tube on the shift shaft!

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    Then it only remained to rotate the header to bring the collector end down and the exhaust port flange up:

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    New gaskets:
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    A couple of nuts tightened at each end on the exhaust port flange, here's the clearance to the main frame tube:
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    (That end nut has to come off again to insert the starter heat shield mount bracket)

    My summary - once I decided to remove the right side front engine mount, unbolt the underside center bolt of the left front engine mount, raise the front of the engine by 1/2", the OEM header came out pretty easily; and the replacement Tubi header went back in even easier.

    Reminder, this was taking out a Euro header, no sampling tubes etc to deal with, and that the front bank timing belt cover was off, giving extra clearance - but I'd certainly recommend considering this method of removing and replacing the front header without having to disconnect multiple fuel lines and draining the fuel tanks in order to move the right fuel tank out of the way.
     
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  8. Nuvolari

    Nuvolari F1 Veteran
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    Rob C.
    Nicely done and well documented. Thank you.

    I pulled my US spec (with the heat shielding) front headers off on jack stands and without removing either tank. It is a tricky job but doable.
     
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  9. trs666

    trs666 Karting

    Apr 17, 2014
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    Göteborg, Sweden
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    Tommi S.
    Excellent write up again Gordon. I ,must confess that when wondering if i dare to buy my 59003 i found your thread on Miata forum and realised that maintain a 308 is doable and quite fan with good tools, some wrenching experience and good nerves. Thanks.
    ///TRS
     
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  10. thorn

    thorn F1 Rookie
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    Aug 7, 2012
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    Tallahassee, FL
    Great thread, Gordon. Looks like stellar progress.
     
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