novice attempts head gasket replacement
#41
Posted 10-12-2017 10:17 AM
Leaving the bottom bolt out of the coil bracket does seem to increase the likelihood of the top flanges cracking, but adding a large and fairly thick flat washer between flange and bolt head seems to prevent it.
#42
Posted 10-12-2017 11:03 PM
Good news! It's alive! I had it running for about fifteen minutes tonight to flush the coolant and oil through. I'll drain it tomorrow and set the timing. Only minor problems noted so far including valve noise and a small exhaust leak under the car.
This has been a bonding experience, but not sure I trust the thing yet. Race is Saturday, so we'll see.
GTL NA 1.6 Miata #181
#43
Posted 10-13-2017 08:40 AM
Any reason you did not replace the small coolant hoses that go to the IAC? A coolant leak at any place can ruin all your hard work. Those hoses are like $5 each
Dave Wheeler
Advanced Autosports, the nations most complete Spec Miata shop
Author, Spec Miata Constructors Guide, version 1 and 2.0
Building Championship winning cars since 1995
4 time Central Division Spec Miata Champion car builder 2012-2013-2014-2017
Back to Back June Sprints Spec Miata 1-2 finishes 2016 and 2017
5 time June Sprints winner in Mazda's
6 Time Northern Conference Champion Car Builder
2014 SCCA Majors National point Champion car builder
2014 SCCA Runoffs winner, T4 (Bender)
2014 Central Division Champion, ITS (Wheeler)
2013 Thunderhill 25 hour winning crew chief
2007 June Sprints winner, (GT1, Mohrhauser)
Over 200 race wins and counting.
www.advanced-autosports.com
dave@advanced-autosports.com
608-313-1230
#44
Posted 10-13-2017 09:59 AM
Well, I guess I just didn't think of that, Dave. If the hoses looked rough I would have, but when I inspected all the rubber bits, they seemed ok. On top of that, I didn't manage my time very well and most of the work and decisions were happening in the last few days and so there were a number of things I decided not to do. The fact that I'm still doing final adjustments a few hours before loading the trailer is a good indication of how poorly I've used my time.
This weekend is the last race for the year for me so I'll plan to replace most of the hoses during the winter.
I've got a new gadget for this project, a vacuum type coolant filler (sort of an Airlift tool) and it inherently tests the integrity of the cooling system by vacuum testing it for leaks. The system passed just fine, at least once I had correctly torqued the radiator drain plug.
GTL NA 1.6 Miata #181
#45
Posted 10-13-2017 10:37 AM
BTW, put a set screw or simple bolt into those T-nuts at the top of each shock. The design isn’t great in that they don’t really torque into place, that nut just compresses the yellow bushings until it bottoms out on a big washer. With no stretch putting load on the threads it can and likely will back off causing you a lot of grief. You don’t want thread locker on there because it makes removal difficult as the shock rod will spin, but a jam bolt will provide a properly torqued stop that is simple to remove.
#46
Posted 10-13-2017 11:04 AM
Not busting Steve's balls, but my memory told me the shoulder nut bottomed out to the red aluminum washer. I chose to mark my shaft and nut rather than using the jamming set screw. No issue to date.
Copied from 5X/FatCat
Without an impact wrench, there will be more resistance as the nut turns so you will have to use stronger means to keep the shaft from spinning. A strap wrench works well, as does a mouse pad or other thick, high-friction material held inside pliers, etc. Whatever your approach, be sure the shaft does not spin as this may damage internal seals.
Once the upper bushings are centered and tightened, torque the upper nut to approximately 20-25 lb-ft. The goal in tightening is for the shoulder nut to make contact with the red washer, properly loading the MCU bushings to their operating state. The Loctite ensures the nut remains torqued.
#47
Posted 10-13-2017 12:03 PM
#48
Posted 10-13-2017 12:54 PM
I have seen many of those nuts back out. Pro and amateur installation alike. The jam screw is important
Dave Wheeler
Advanced Autosports, the nations most complete Spec Miata shop
Author, Spec Miata Constructors Guide, version 1 and 2.0
Building Championship winning cars since 1995
4 time Central Division Spec Miata Champion car builder 2012-2013-2014-2017
Back to Back June Sprints Spec Miata 1-2 finishes 2016 and 2017
5 time June Sprints winner in Mazda's
6 Time Northern Conference Champion Car Builder
2014 SCCA Majors National point Champion car builder
2014 SCCA Runoffs winner, T4 (Bender)
2014 Central Division Champion, ITS (Wheeler)
2013 Thunderhill 25 hour winning crew chief
2007 June Sprints winner, (GT1, Mohrhauser)
Over 200 race wins and counting.
www.advanced-autosports.com
dave@advanced-autosports.com
608-313-1230
#49
Posted 10-13-2017 01:50 PM
Steve one of your points is, "With no stretch putting load on the threads it can and likely will back off causing you a lot of grief."
My point is, use an impact wrench while holding the shock shaft. To each their own. RadioRon, pay no attention to the bickering.
"Without an impact wrench, there will be more resistance as the nut turns so you will have to use stronger means to keep the shaft from spinning. A strap wrench works well, as does a mouse pad or other thick, high-friction material held inside pliers, etc. Whatever your approach, be sure the shaft does not spin as this may damage internal seals."
#50
Posted 10-13-2017 02:58 PM
#51
Posted 10-13-2017 03:30 PM
#52
Posted 10-13-2017 03:38 PM
My point was that no matter how you hold your shaft (please, no pictures!!) I don’t think you are getting the torque that you need.
You get the last comment if you choose because this is my last comment. If or when I remove a shock nut, I'll use a torque wrench and let you know the exact number. There is no Loctite on the threads.
#53
Posted 10-13-2017 05:19 PM
#54
Posted 10-14-2017 09:33 AM
Cock that AFM so the connector is at least 45 degrees down and your dyno air/fuel ratio will have a better chance of happening when you are turning left and right. It also helps lean out the top end, because the flow has to "lift" the door. Some AFMs even prefer a pure vertical (connector down) orientation.
And clean that damn filter of oil and run it dry. I've seen dirty and over-oiled air filters cost 1+ HP (Guthrie! Murdick!)
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#55
Posted 10-16-2017 11:56 AM
Hello everyone. I am happy to report that my engine repair was successful in lasting the entire race weekend without any problems at all. In total I drove, over two days, one practice, two qualifying sessions and three races (20 minutes each). I admit to being tentative on the throttle for the first two sessions on track, but really gave it the beans in the races, and all was well. Unfortunately, none of the work I did improved my driving and so I did not place well at the checkered flag. But it was fun. My thanks to all of you for your encouragement and tips.
- dstevens, Bench Racer, Todd Green and 1 other like this
GTL NA 1.6 Miata #181
#56
Posted 10-16-2017 07:58 PM
Hello everyone. I am happy to report that my engine repair was successful in lasting the entire race weekend without any problems at all. In total I drove, over two days, one practice, two qualifying sessions and three races (20 minutes each). I admit to being tentative on the throttle for the first two sessions on track, but really gave it the beans in the races, and all was well. Unfortunately, none of the work I did improved my driving and so I did not place well at the checkered flag. But it was fun. My thanks to all of you for your encouragement and tips.
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