Page 1 of 2 12 LastLast
Results 1 to 15 of 19

Thread: NB1 head on NA. What should the machine shop do?

  1. #1
    5,000 rpm - there be torque here! The Driver's Avatar
    Drives
    1996 Montego Blue Leather Package + 5 Speed = Torsen II
    Location
    Lakewood (Green Mountain), CO.
    Join Date
    Dec 2011
    Posts
    3,369
    Thanks Given
    933
    Thanked 483 Times in 283 Posts

    NB1 head on NA. What should the machine shop do?

    Alright folks, looks like I FINALLY bought my 96 Montego, a well deserved NB1 head.

    This post is not regarding the actual install, but I'm planning to send the head to a machine shop for some light resurfacing. I want that head to fully mate with the engine block currently on the car.

    Before I send it to the machine shop, what should I tell the machine shop operator? BTW, the NB1 head has less than 100K miles and remember, this is for a turbo build up!


    FIRE AWAY!
    96 Montego, replacing a 95M... I miss: My running peeps in Tampa, running barefoot @ Clearwater Beach and First Choice BBQ, in Brandon. In So Cal I miss: The Malibu Canyons, CA 33 and In & Out Burgers ! I'm from Tampa, if I was from Tampa Bay, I'd be a fish!

  2. The Following User Says Thank You to The Driver For This Useful Post:

    Phatmiata (02-26-2015)

  3. #2
    Ninja Messiah kung fu jesus's Avatar
    Drives
    1999 White
    Location
    Atlanta, GA
    Join Date
    Dec 2011
    Posts
    15,852
    Thanks Given
    2,791
    Thanked 7,202 Times in 3,433 Posts
    If the head is disassembled, 5 cut valves, port, polish, gasket match, new valve guides.

  4. The Following User Says Thank You to kung fu jesus For This Useful Post:

    tsingson (02-26-2015)

  5. #3
    5,000 rpm - there be torque here! The Driver's Avatar
    Drives
    1996 Montego Blue Leather Package + 5 Speed = Torsen II
    Location
    Lakewood (Green Mountain), CO.
    Join Date
    Dec 2011
    Posts
    3,369
    Thanks Given
    933
    Thanked 483 Times in 283 Posts
    Quote Originally Posted by kung fu jesus View Post
    If the head is disassembled, 5 cut valves, port, polish, gasket match, new valve guides.
    Not is not disassembled, and dude all this would cost mad cash! But gasket match and new valve guides sounds like a good start. Within a budget, anything else?
    96 Montego, replacing a 95M... I miss: My running peeps in Tampa, running barefoot @ Clearwater Beach and First Choice BBQ, in Brandon. In So Cal I miss: The Malibu Canyons, CA 33 and In & Out Burgers ! I'm from Tampa, if I was from Tampa Bay, I'd be a fish!

  6. #4
    Ninja Messiah kung fu jesus's Avatar
    Drives
    1999 White
    Location
    Atlanta, GA
    Join Date
    Dec 2011
    Posts
    15,852
    Thanks Given
    2,791
    Thanked 7,202 Times in 3,433 Posts

    NB1 head on NA. What should the machine shop do?

    With some careful organization, disassembling and reassembling a head is actually kinda easy. A valve spring compressor is really the only tool you need to rent.

    I am a little ambivalent towards your goals with the turbo, but an NA BP motor is a relatively low compression engine. Shaving the head is something you could do to bump compression.

    Among what I mentioned, I would add new valve seals, which are very easy to do with the head apart. I think ARP head studs are an absolute must-add. Unshrouding the valves in the CC would be beneficial for flow, maybe a plunge cut to the bowls would be relatively inexpensive without a lot of hand work P&P entails. Get a quality head gasket, too. If you haven't, it would be a good time to plan for a coolant reroute upon reassembly.

  7. The Following User Says Thank You to kung fu jesus For This Useful Post:

    tsingson (02-26-2015)

  8. #5
    Ninja Messiah kung fu jesus's Avatar
    Drives
    1999 White
    Location
    Atlanta, GA
    Join Date
    Dec 2011
    Posts
    15,852
    Thanks Given
    2,791
    Thanked 7,202 Times in 3,433 Posts
    Oh, and clean the piston crowns, inspect the cylinder bores while the head is off. Knock off any carbon ridges, if present.

  9. The Following User Says Thank You to kung fu jesus For This Useful Post:

    tsingson (02-26-2015)

  10. #6
    Ninja Messiah kung fu jesus's Avatar
    Drives
    1999 White
    Location
    Atlanta, GA
    Join Date
    Dec 2011
    Posts
    15,852
    Thanks Given
    2,791
    Thanked 7,202 Times in 3,433 Posts
    Have the intake manifold cleaned/tanked.
    I am very happy how my e30 IM turned out having someone else have at it. The mating surfaces were well done, too. $27 wiped out 28 years of crud.

  11. The Following User Says Thank You to kung fu jesus For This Useful Post:

    tsingson (02-26-2015)

  12. #7
    Ninja Messiah kung fu jesus's Avatar
    Drives
    1999 White
    Location
    Atlanta, GA
    Join Date
    Dec 2011
    Posts
    15,852
    Thanks Given
    2,791
    Thanked 7,202 Times in 3,433 Posts
    Nice time to have the IM and VC powdercoated, too!

  13. The Following 2 Users Say Thank You to kung fu jesus For This Useful Post:

    Demon I Am (02-26-2015),tsingson (02-26-2015)

  14. #8
    5,000 rpm - there be torque here! The Driver's Avatar
    Drives
    1996 Montego Blue Leather Package + 5 Speed = Torsen II
    Location
    Lakewood (Green Mountain), CO.
    Join Date
    Dec 2011
    Posts
    3,369
    Thanks Given
    933
    Thanked 483 Times in 283 Posts
    KFJ, I wish you would've post in one post...

    But here it goes: head is still in FL, the machining will more than likely take place in Tampa. I neither have the time, nor the inclination to disassemble the head. I run, I rock climb, I snow ski and mountain bike; on top of dating. In any weekend I'll do 3-4 of those activities. In short, I'm busy enough, last thing I want is to eff up the head.

    I don't want the compression increased, as that would mean fewer turbo lbs. The reason for the NB1 head/intake is to reach approx 240 or fewer hp @ 10-11 lbs of boost.

    Intake cleaning, that I'll do!

    No powder coating. Got to save for the MS3. I only have so much $ to spend.
    96 Montego, replacing a 95M... I miss: My running peeps in Tampa, running barefoot @ Clearwater Beach and First Choice BBQ, in Brandon. In So Cal I miss: The Malibu Canyons, CA 33 and In & Out Burgers ! I'm from Tampa, if I was from Tampa Bay, I'd be a fish!

  15. The Following User Says Thank You to The Driver For This Useful Post:

    BoBo (02-27-2015)

  16. #9
    3,000 rpm - starting to feel the power BoBo's Avatar
    Drives
    & Rides
    Location
    Playa Del Rey, CA
    Join Date
    Apr 2013
    Posts
    920
    Thanks Given
    375
    Thanked 293 Times in 172 Posts
    Of course anything can happen within a 100k miles, but assuming the (NB head) was taken care of most likely you will just need a few things done on the head. A local machine shop usually charges $250-450 for the typical stuff such as: Checking for cracks, hot tank cleaning,resurfacing, and Valve guide & seat servicing. You might not even need the valve guides & seats done. I had one of my 1.6 heads rebuilt at 160k and the guides were still within spec but I had it done anyway since it was already off of the block.

    If your gonna aim for 200-240hp or less then you better treat transmissions like consumables. Maybe I just had a bad luck with transmissions. My original tranny went out within the fist year of having around 240hp on my 92na. My 1st replacement went out after 30k of normal driving on 225hp plus 1 track day. My 2nd replacement lasted until I sold the car. At that time my 92 was tuned down to 180hp but was still fast in every way. I can't wait to boost my 96 I will probably just buy the FM Voodoo 2 and be happy with under 200hp. The mazdaspeed miata tranny should be able to handle 240+hp.
    Last edited by BoBo; 02-27-2015 at 02:03 AM.
    08 Kawasaki Ninja 250R Tuned/Track Prepared
    04 Z4 2.5 M Sport Package
    01 SLK 230 Kompressor AMG Sport Package

  17. The Following User Says Thank You to BoBo For This Useful Post:

    kung fu jesus (02-27-2015)

  18. #10
    Ninja Messiah kung fu jesus's Avatar
    Drives
    1999 White
    Location
    Atlanta, GA
    Join Date
    Dec 2011
    Posts
    15,852
    Thanks Given
    2,791
    Thanked 7,202 Times in 3,433 Posts
    Savvy advice ^.

    Here's what I'm thinking after reading the last two posts, it is only conjecture, so take it as you will.

    Bobo brings up a REALLY good point... Are you going to use the extra 20-40 hp for your intentions? I ran my turbo configurations between 160 to 240 hp. Honestly, the car felt best to drive between 180-200hp.

    I am concerned that if you don't have time to mess with headwork, what are you going to do with the car running a borderline ragged 240hp? The more more power you run, the more support and attention you have to address to all the systems exponentially. Anyone can make 240 with the proposed parts you list, but can you make it reliable and still enjoy it? Making the turbo work harder to make the power when you have opportunities to help it with tertiary mods is leaving money on the table, or flushing money down the shitter.

    So, what do want to do? Make the power, or make the power reliably? Planning goes a long way to hitting goals, but cutting corners leads to oversight. Leaving it to someone one else to deal with the car when things go pear-shaped get expensive, often.

  19. The Following 3 Users Say Thank You to kung fu jesus For This Useful Post:

    BoBo (02-27-2015),NCGreasemonkey (01-20-2016),Slampen (02-28-2015)

  20. #11
    5,000 rpm - there be torque here! The Driver's Avatar
    Drives
    1996 Montego Blue Leather Package + 5 Speed = Torsen II
    Location
    Lakewood (Green Mountain), CO.
    Join Date
    Dec 2011
    Posts
    3,369
    Thanks Given
    933
    Thanked 483 Times in 283 Posts
    So far, I've only tracked my car twice, both times @ FM's summer camp; since buying it in May 2010. Once I go Turbo, Bob Bondurant/Skip Barber type of drivng school is a strong and real possibility.

    What racers refer to as "consumables" I refer to as: dating, traveling, road running, climbing gear budget.

    As for the projected power levels, I have driven a almost two dozens turbo cars (all but two were FM's, the others were Begi), and the bell curve would show Skip Cannon's 300 hp yellow Miata (not fair, that car has a 1.9 built engine, with forged internals; and two maybe three maid less than 210 hp.

    In other words, 20-21 cars with dynoed 220-250 hp. Of course, the more power, the more heat created and the more things will go wrong. But based on all the info I have gatherer thus far, I feel perfectly comfortable that once my Miata goes turbo, that the car will not impode/explode just because the car is dynoed @ 240 hp @ 6K ft @ 5,700 rpms.


    Heck, Skip Cannon himself told me that if the head is in good shape, I could just slap it in. But I don't honestly know the heads condition, and I'll have it checked prior to install. I'm big on maintenance prevention, and GOD knows I'm not trying to cut corners, but I'm also a big believer in not let project creep take a life of it's own either.

    Also about the trannies, most of the turbo Miata folks around here (including two techs @ Flyin Miata), go with the 5 speed as opposed to the 6 speeds, for it's superior driving characteristics. That includes individuals who have had their working 6 speeds replaced on their Mazdaspeed Miatas.

    I know ya both mean well, but I'm far from doing this while blind. I've been researching turboing the Miata, more or less since 2010. The whole NB1 head conversion, is what's rather recent, as I was actually leaning on dropping an NB2 engine instead.
    96 Montego, replacing a 95M... I miss: My running peeps in Tampa, running barefoot @ Clearwater Beach and First Choice BBQ, in Brandon. In So Cal I miss: The Malibu Canyons, CA 33 and In & Out Burgers ! I'm from Tampa, if I was from Tampa Bay, I'd be a fish!

  21. #12
    Ninja Messiah kung fu jesus's Avatar
    Drives
    1999 White
    Location
    Atlanta, GA
    Join Date
    Dec 2011
    Posts
    15,852
    Thanks Given
    2,791
    Thanked 7,202 Times in 3,433 Posts
    Good luck!

  22. The Following User Says Thank You to kung fu jesus For This Useful Post:

    The Driver (03-02-2015)

  23. #13
    5,000 rpm - there be torque here! The Driver's Avatar
    Drives
    1996 Montego Blue Leather Package + 5 Speed = Torsen II
    Location
    Lakewood (Green Mountain), CO.
    Join Date
    Dec 2011
    Posts
    3,369
    Thanks Given
    933
    Thanked 483 Times in 283 Posts
    KFJ, it seems Keith Tanner agrees with you, when I asked him the same question, with all the info I gave you, this is what he had to say: "Service wise? Just ask the machine shop to give it a valve job. They'll probably do new guides and seals as part of it. But if they're a good machine shop, they'll know what to do".

    So I was wrong, you were right, and now we have an informative thread for future NB1 head swaps!
    96 Montego, replacing a 95M... I miss: My running peeps in Tampa, running barefoot @ Clearwater Beach and First Choice BBQ, in Brandon. In So Cal I miss: The Malibu Canyons, CA 33 and In & Out Burgers ! I'm from Tampa, if I was from Tampa Bay, I'd be a fish!

  24. #14
    4,000 rpm - entering the fun zone wannafbody's Avatar
    Join Date
    Jan 2012
    Posts
    1,412
    Thanks Given
    237
    Thanked 285 Times in 202 Posts
    I'd leave the compression ratio as is. I'd invest in a square top manifold to match the BP4W head.

  25. #15
    5,000 rpm - there be torque here! The Driver's Avatar
    Drives
    1996 Montego Blue Leather Package + 5 Speed = Torsen II
    Location
    Lakewood (Green Mountain), CO.
    Join Date
    Dec 2011
    Posts
    3,369
    Thanks Given
    933
    Thanked 483 Times in 283 Posts
    ^ Nah, I don't want to move the power curve any higher. That, and I don't see the bennie of the square top.

    Ultimately, I want a torque curve, as flat as Tampa.
    96 Montego, replacing a 95M... I miss: My running peeps in Tampa, running barefoot @ Clearwater Beach and First Choice BBQ, in Brandon. In So Cal I miss: The Malibu Canyons, CA 33 and In & Out Burgers ! I'm from Tampa, if I was from Tampa Bay, I'd be a fish!

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •