Looking for opinions on minor mods during upcoming engine refresh

Engines, Transmissions & Final Drive questions and answers

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lonesailor
Fast Driver
Posts: 144
Joined: Sat Feb 13, 2016 5:09 pm
Vehicle: NA8

Looking for opinions on minor mods during upcoming engine refresh

Postby lonesailor » Wed Apr 14, 2021 4:13 pm

I am still planning a refresh of the engine in my '96 NA8, hopefully,it will just need a hone and rings, and bearings if needed. it will happen as soon as I can get everything together. It is still running fairly well with no nasty noises, but compression is at the low end of specs. I have a few queries and would appreciate some feedback. First, I would like to lighten the flywheel somewhat but don't want to pay for an aftermarket one, I think NA6 flywheels would be like hens teeth these days. Has anybody had experience with machining some weight out of the existing unit? second I also would like to replace the harmonic damper, again I don't want to spend the $1000 plus asked by the usual suspects, any alternate suggestions? and third, what do people think about engine dynamic balancing, is worth the money? The car is mostly stock and used as a fun car mainly on the road, I plan a little port matching and tidy up while the head is off. I don't abuse the car normally but I do do an occasional trackday, not to try for silverware but just to keep my eye in and to convince myself I still can.

manga_blue
Forum Guru
Posts: 4897
Joined: Mon Apr 24, 2006 7:27 pm
Vehicle: NA8
Location: Moruya, NSW

Re: Looking for opinions on minor mods during upcoming engine refresh

Postby manga_blue » Thu Apr 15, 2021 10:06 am

MX5Mania had the lip shaved off the flywheel on my NA8 years ago when they replaced the clutch. They said they do that routinely when they do clutches. I think the original flywheel is a legacy from it being an Astina engine, it's not a sports car flywheel at all. Anyway it made a very noticeable improvement in response, mostly in 1st and 2nd.

I did a full rebuild of my BP05 years ago with full balancing, honing, decking, valve cutting, etc plus a lot of simple DIY improvement work. Big gains in both. I'm short of time now, will do a fuller post when I get some time.
’95 NA8

93_Clubman
Speed Racer
Posts: 11852
Joined: Mon Aug 08, 2005 11:35 pm
Vehicle: Clubman
Location: Melbourne

Re: Looking for opinions on minor mods during upcoming engine refresh

Postby 93_Clubman » Sat Apr 17, 2021 11:33 am

lonesailor wrote:think NA6 flywheels would be like hens teeth these days.

Haven't tried to get one recently, but there must some out there - if not, fwiw, MX5 BP flywheels got slightly lighter than previous MX5 BP flywheels starting with the 1996-1997 NA8. NB8A was slightly lighter again & NB8B slightly lighter again.


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