Re: V8 Miata - The Lemony way

Q: Are you going to have to do a custom driveshaft to fit this under your miata or will the end of the transmission match up with the stock position on the miata and can therefore be reused (if you decide to stick with the rear miata diff for at least one race).
Regards,
-g

Myopic Motorsport's #888 Ceci n'est pas une Citron Thunderbird ("This is not a lemon" but a 1995 tbird w/ 93 V8 swap + shopping cart rear wing + engine mounted frito maker)
2017 Sears Pointless Organizer’s Choice
Frito Making Tbird from 2018 Sears Pointless Engine Heat BBQ - http://goo.gl/csaet4

Re: V8 Miata - The Lemony way

gunn wrote:

Q: Are you going to have to do a custom driveshaft to fit this under your miata or will the end of the transmission match up with the stock position on the miata and can therefore be reused (if you decide to stick with the rear miata diff for at least one race).
Regards,
-g

Nothing will really work right with the stock miata driveshaft, even if we ran the stock diff.  The transmission won't be in the right place, and it won't mate with the miata shaft anyway.  There's a local driveline shop with a dude named Ron that will weld a couple shafts together and balance it for real cheap.  Even comes with an aerosol overhaul too.  That way it will have the right ends on it, and be the right length.

Petrosexual Racing - 4.9 HT swap/Trashback Miata
https://forums.24hoursoflemons.com/view … p?id=35746
"Seriously, WTF Award" - 2017 - Spaghettio Bribe
BFE GP 1st in C - 2018

Re: V8 Miata - The Lemony way

I have a miata driveshaft and it's a spindly little thing.  I wouldn't run it behind a V8.

1990 RX7 "Mazdarita" 
1994 Jaguar XJ12 (Winner C-Class 2013 Sears Pointless)
1964 Sunbeam Imp (IOE 2013 Sears Pointless)
1980 Rover SD1 (I Got Screwed 2014 Return of Lemonites) (Sold -> Houston.  Gone and forgotten)

29 (edited by Rustyjeep 2017-10-31 09:37 AM)

Re: V8 Miata - The Lemony way

The offer will stand for this motor until the one day someone finally cleans out the shop. Complete lemony fresh 4.9 that's been taking up my space...since 2004.

EDIT: I just thought of the perfect hot potato/judge bribe.

Team BAD Company Endurance
Acura RSX #0
4 times losers, and counting...
"I got screwed" winners? 2018 Cure for Gingervitis, 5th on laps overall 2018 Elite meet to Cheat

Re: V8 Miata - The Lemony way

Took the motor apart after seeing some evidence of water in the intake.  A little cylinder rust is probably fine right?  Shit'll buff out. 

The open deck, floating cylinders are kind of weird too.  Its surprising these motors didn't have more head gasket issues.  This should be the perfect endurance race motor.

https://farm5.staticflickr.com/4520/26939248419_069b49592c_b.jpg

Petrosexual Racing - 4.9 HT swap/Trashback Miata
https://forums.24hoursoflemons.com/view … p?id=35746
"Seriously, WTF Award" - 2017 - Spaghettio Bribe
BFE GP 1st in C - 2018

Re: V8 Miata - The Lemony way

egesledder wrote:

Took the motor apart after seeing some evidence of water in the intake.  A little cylinder rust is probably fine right?  Shit'll buff out. 

The open deck, floating cylinders are kind of weird too.  Its surprising these motors didn't have more head gasket issues.  This should be the perfect endurance race motor.

https://farm5.staticflickr.com/4520/26939248419_069b49592c_b.jpg

I see no way this can end in failure.

Re: V8 Miata - The Lemony way

This is great, can't wait to see it go!

Re: V8 Miata - The Lemony way

Where are you finding cheap custom axles for the 8.8? I'm in the middle of building an 8.8 IRS setup for a Datsun, and am somewhat hung up on the axles. Factory five no longer sells the narrow axles, and they are over twice as much for the same axles from DSS.

I think the route i'm going to go is cut the tripod off a MKVIII inner CV and flange it to use a complete F150 driverside front axle. The stub for the 8.8 front diff almost works in the rear, but not quite. Just curious what other cheap options there are.

Re: V8 Miata - The Lemony way

mgbgt89 wrote:

Where are you finding cheap custom axles for the 8.8? I'm in the middle of building an 8.8 IRS setup for a Datsun, and am somewhat hung up on the axles. Factory five no longer sells the narrow axles, and they are over twice as much for the same axles from DSS.

I think the route i'm going to go is cut the tripod off a MKVIII inner CV and flange it to use a complete F150 driverside front axle. The stub for the 8.8 front diff almost works in the rear, but not quite. Just curious what other cheap options there are.


Yea, I was mistaken with the prices on the axles I found, they were DSS axles listed at $315 and it made it sound like it was a pair.  Turns out it was per-axle.  I ended up buying the pair of Factory Five axles that MDG offered up earlier, then built them up with some used 8.8 axles.  Its far more axle than necessary, but it has a workable gear ratio now and should hold up to lots of abuse.  I sold the Miata torsen diff for $700, so even after everything I'm coming out ahead cost wise on the rear end setup.

The F150 parts solution is intriguing, let me know if you work something out.

Petrosexual Racing - 4.9 HT swap/Trashback Miata
https://forums.24hoursoflemons.com/view … p?id=35746
"Seriously, WTF Award" - 2017 - Spaghettio Bribe
BFE GP 1st in C - 2018

Re: V8 Miata - The Lemony way

If we run both of these, will it be twice as classy?

https://farm5.staticflickr.com/4621/39098240184_a2db92a0e9_h.jpg

Petrosexual Racing - 4.9 HT swap/Trashback Miata
https://forums.24hoursoflemons.com/view … p?id=35746
"Seriously, WTF Award" - 2017 - Spaghettio Bribe
BFE GP 1st in C - 2018

Re: V8 Miata - The Lemony way

Subscribed smile

Re: V8 Miata - The Lemony way

You should definitely put the v8 in the tiny Miata. Get some ideas from these guys.. https://www.flyinmiata.com/projects/build_diaries.php  Hopefully you have it ready for Joliet big_smile

Re: V8 Miata - The Lemony way

The plan is to have it ready for the June Colorado race, so we'll see how it goes.  The car is in Colorado for the swap project right now, and the stock 1.8 is getting pulled next week after one last track day.  Pics will start coming after that.

Petrosexual Racing - 4.9 HT swap/Trashback Miata
https://forums.24hoursoflemons.com/view … p?id=35746
"Seriously, WTF Award" - 2017 - Spaghettio Bribe
BFE GP 1st in C - 2018

Re: V8 Miata - The Lemony way

This is a glorious and terrible project, and I look forward to seeing how it turns out.

Command Pilot/Flight Director, Escape Velocity Racing
Index of Effluency, Heroic Fix, Class C Trophy, now hopelessly gunning for Class B.
Currently 1-2 vs. Team Fairlylame in the Class of 1964 Championships

Re: V8 Miata - The Lemony way

egesledder wrote:

If we run both of these, will it be twice as classy?

The older version with the couronne and merlettes is considerably classier than the newer version, so I'd say together they're perhaps one and a half times as classy as the earlier one by itself.

Then again, you don't need to stop at just two.

1982 MG Metro 1300: IOE 2015 Pacific Northworst GP, Longest Distance 2010 Cd'L Box Wine Country Classic
1980 KV Mini 1: Worst of Show and Fright Pig Supremo 2009 Concours d'Lemons
1978 H Special: Second-Round Elimination 2010 Lemons Pinewood Derby at Sears Pointless
1967 SAAB 96: IOE 2012 Pacific Northworst GP

Re: V8 Miata - The Lemony way

That older Caddy hood ornament is perfection.

Congratulations! You have achieved the rare feat of making me interested in a Miata.

Re: V8 Miata - The Lemony way

Those engines are TERRIBLE!

(I support this plan)

Mike @ Charnal House Inc.
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Re: V8 Miata - The Lemony way

Stock motor is out and we've started hacking stuff up to fit the caddy in there.  I don't understand how people put bigger v8's in these miatas, its going to be tight.  We'll be adding strength back after the motor is where we want it.

https://farm5.staticflickr.com/4716/25421362357_a518e748bd_h.jpg

https://farm5.staticflickr.com/4656/39581053844_38b712e049_h.jpg

https://farm5.staticflickr.com/4697/39581030044_abfe5e1e72_h.jpg




There's still quite a bit of frame damage left from when this car was wrecked before we bought it originally.  Its hard to tell in this pic, but that whole area is pretty crumpled.  We'll be welding a bunch of stuff back in there to add strength back:

https://farm5.staticflickr.com/4762/39581041164_92a59a2d81_h.jpg



Also got the rear drivetrain squared away with the ford 8.8 diff.  Now we will have 3.27 gears and negative $200 after selling the miata torsen diff.

https://farm5.staticflickr.com/4620/38482531160_c40f2e1761_h.jpg

Petrosexual Racing - 4.9 HT swap/Trashback Miata
https://forums.24hoursoflemons.com/view … p?id=35746
"Seriously, WTF Award" - 2017 - Spaghettio Bribe
BFE GP 1st in C - 2018

Re: V8 Miata - The Lemony way

After some tasteful firewall bashing, its in place:

https://farm5.staticflickr.com/4671/40306961372_6cbb8ff341_b.jpg

Petrosexual Racing - 4.9 HT swap/Trashback Miata
https://forums.24hoursoflemons.com/view … p?id=35746
"Seriously, WTF Award" - 2017 - Spaghettio Bribe
BFE GP 1st in C - 2018

Re: V8 Miata - The Lemony way

I had to register...just to reply: http://i.imgur.com/YXpiTvG.jpg

46 (edited by egesledder 2018-03-14 01:39 PM)

Re: V8 Miata - The Lemony way

So a couple updates.  The first is that for some reason, a fiero clutch disc fits the dodge transmission input shaft perfectly.  No idea why, but this means that we can use the same conversion flywheel that all the fiero swap guys use.  Real neat.

https://farm5.staticflickr.com/4698/39633639435_3937728ee0_h.jpg




Another issue is the exhaust.  The stock 4.9 FWD setup had cast iron manifolds that go in the wrong direction.  There are obviously no aftermarket options, so we're going to make a custom set of headers the lemony way.  I found this set of dodge 360 headers on a 70's W200 at the junk yard for $40.  These will be hacked up to use the bends in a new set to fit the 4.9 and miata.  The plates were machined by me to fit the 4.9.

Kind of cool how much smaller the 4.9 is when looking at size difference in the flanges.

https://farm5.staticflickr.com/4626/39633667605_ab17cf7fa0_h.jpg

Petrosexual Racing - 4.9 HT swap/Trashback Miata
https://forums.24hoursoflemons.com/view … p?id=35746
"Seriously, WTF Award" - 2017 - Spaghettio Bribe
BFE GP 1st in C - 2018

Re: V8 Miata - The Lemony way

So we ran into a bit of an issue last week, the input shaft on the Dodge Dakota AX-15 transmission was about 3/4" too short for the fiero clutch and flywheel.  I machined an alignment jig out of a bunch of scrap aluminum sitting around, cut the bell housing down, and then welded it back.  This seemed a lot easier than going back to the drawing board and switching transmissions or clutch/flywheel, and fits the Lemons theme better.  I think it should work pretty well and everything lines up nicely now.

https://farm1.staticflickr.com/786/40898550351_30ceeaddf8_k.jpg

https://farm1.staticflickr.com/821/26026161877_2e1a75a6a7_k.jpg

https://farm5.staticflickr.com/4775/40856469142_bd8478ff5f_k.jpg

Petrosexual Racing - 4.9 HT swap/Trashback Miata
https://forums.24hoursoflemons.com/view … p?id=35746
"Seriously, WTF Award" - 2017 - Spaghettio Bribe
BFE GP 1st in C - 2018

Re: V8 Miata - The Lemony way

boy that is a lot of work... Isn't there already a SBC swap kit out there?

"get up and get your grandma outta here"

Re: V8 Miata - The Lemony way

^ I think it's a case of it being easier to use the machining tools you already have vs sourcing new parts.  I think most of the aftermarket stuff is to adapt an RWD auto trans to this fine engine.  The Fiero bellhousing bolts up and  is easily obtained on the cheap.  There are a multitude of bad decisions being made on this build but this seems to be one of the better ones.  Carry on.  I also have a curiosity about how machinists get stuff like this to line up so this is educational to watch.

1990 RX7 "Mazdarita" 
1994 Jaguar XJ12 (Winner C-Class 2013 Sears Pointless)
1964 Sunbeam Imp (IOE 2013 Sears Pointless)
1980 Rover SD1 (I Got Screwed 2014 Return of Lemonites) (Sold -> Houston.  Gone and forgotten)

Re: V8 Miata - The Lemony way

The only swap "kit" I've seen for this motor is for the fiero, and is basically just a couple engine mounts and some exhaust, but that is a transverse mounted setup.  There are no longitudinal parts for this motor, and really no aftermarket parts available at all, but that just makes the motors cheaper to find.

Everyone swaps in small block gm or ford motors, but those are expensive to build and far outside of a Lemons budget.  So far, starting with an official $500 car, selling all the Miata parts and getting everything we need to get this motor running, we are at -$53 for the items related to the Lemons budget.  As in, there's technically still $550 that we could spend, but will probably spend it on beer and gas instead of parts.  That's even including all the rear end stuff and the custom flywheel.

We weighed the assembled engine with flywheel, clutch, starter, and alternator last night and it is 85lbs more than the Miata motor with the same stuff.  Not too bad.

Petrosexual Racing - 4.9 HT swap/Trashback Miata
https://forums.24hoursoflemons.com/view … p?id=35746
"Seriously, WTF Award" - 2017 - Spaghettio Bribe
BFE GP 1st in C - 2018