Forged 1.6 Engine build!
 

Hi all,

I am currently in the process of building a forged 1.6 engine.
I have always wanted to build an engine, and after buying my MX5, with worn out piston rings, i have my opportunity to actually do it.

I am aiming for around 250-300WHP in the end with turbo, but i will probably start a bit lower, say 200, and get used to the car at that kind of power level, then turn it up a bit :naughty:

Started off with a 66K 1.6 from eBay, so I have a good reasonably low mileage motor to start with. I have already torn down the block, head and removed pretty much everything, and bagged it all up in lil baggies.

During the process of teardown however, I managed to put a tiny dink in the crankshaft by dropping a bolt onto it!
machine shop said that most people wouldn't have even spotted it, and he can polish it out, no worries. So that is getting done at the moment.
Also, during cleanup of the head, I also discovered a nice meaty scratch under the head gasket leftovers, straight from mazda! Currently getting the head skimmed because of that, and also cleaned.
https://cimg5.ibsrv.net/gimg/www.mia...09fcbbbdee.jpghttps://cimg4.ibsrv.net/gimg/www.mia...4c748be4c7.jpg

I was going to reuse the stock pistons, with forged rods in order to keep costs lower. But while costing up getting new rings, getting my current pistons coated, wrist pins pushed out, and into the new rods.
It turns out, that forged pistons actually work out at pretty much the same price. £450~ to reuse current pistons, and £450~ for supertech forged ones posted from america including import taxes.

The only extra cost there would be I have to get my cylinders bored out .5mm, but that shouldnt be much more than £60 extra.

EDIT:
HOWEVER, i just noticed that the 1.6 forged pistons, only list 90-93. i know you guys in the US didn't get the NB with 1.6 engines.
im not sure if there was actually any differences between the early and late models combustion chambers/stroke. I know they are the same size bore.

i notice that flyin miata listed their forged pistons for the 1.6 as NA/NB and in the additional info it lists 90-93.
so i guess it's fine?
https://www.flyinmiata.com/wiseco-1-...o-pistons.html < Flying miata pistons
https://fab9tuning.com/supertech-forged-pistons/ < Supertech pistons


I'm currently in the process of getting my machine work done and out the way, and I will be ordering up parts soon!

I know its a bit overkill for the power I plan to run, but why not do it while I'm in here!
What does everyone think of my parts list?

Forged Conrods £370.00
Supertech pistons £460
New Clutch with flywheel £320.00
Oil samwich plate £60.00
Oil pressure sender kit £90.00
Cambelt cover middle £31.00
Cambelt cover lower £32.00
Full engine Gasket set £230
Head studs £100
Water pump £58
Antifreeze £27
Oil temp gauge £35
Oil Temp Sensor £15
Oil return adaptor £5
Oil return Cap £4
ACL Race Main bearings £67
ACL thrust Washers £8
ACL Race Conrod Bearings £44
Uprated Oil pump £255

Do you have any legal limitation which made you stick to 1.6L?

Probably really uncommon to find a 1.8 there, so likely expensive.

Nah, they are not uncommon to find, they are more expensive than the 1.6 though.

legal wise, no limits on going to the 1.8 that i am aware of, emissions would be an issue i imagine.
Mostly it's to to with insurance, i'm only 21, and insurance is crazy expensive over here. my mx5 insurance cost me an engine swap as well as turbo and other mods would likely send my insurance up much more than i would be comfortable paying.

its also more of a hassle with paperwork! i just couldnt be arsed with it all. i can make the power i want with a 1.6, so why bother with the extra hassle!

save some cash using EBAY rods..

Really? I have heard questionable things.

They seem a bit good to be true to be honest, I feel like it would be something I would worry about. Something as important as rods i feel is worth spending a bit extra on.

How would the insurance know you have a 1.8L?

How does emissions become an issue when you're going turbo in the first place?

I'm confused, but I digress.

Looking forward to more pictures.

Not sure how US Insurance works but here you have to declare any mods you have done to your car to the insurance company. If you don't, your insurance will be invalidated in the event of an accident if they find out you had undeclared modifications.
​​​​​​
Emissions wise, yea true. But oh well hahaha

duplicate

I just don't know how they'd know how to check for the displacement. If you don't tell them, they won't know to look right?

It's your cash, but I've had Eagle rods (from EBay) in my boosted block for more than 4 years without a worry.

I have Eagle rods in my engine as well.

Yea, i know, its just simply not worth the risk for me!
I can make the power I want with a 1.6, so why bother.
I can't be arsed with telling the DVLA that the displacement has changed either.

Huh, well that is a the cost for eagle rods... Admittedly not from eBay, from a company called H-tune. Fab9tubing eagle rods work out about the same price after tax and shipping.

Eagle is Eagle no matter where you get them.

Some run the "china-bay" no name rods, they can be ok for entry level, mild street strip use.
I have run them in the past with no problems in different engine builds, Just make sure to check the big and little ends for size and install decent ARP cap screws and you'll be ok

Also, if you will be doing more basic street driving than racing, use the basic ACL ( I prefer King) main bearings so you have better embedablity of micro particals in the mains, race bearings should be kept on the rods for impact loading under boost

True, but i dont seem to be able to find eagle rods on ebay over here.
if anyone wants to send me a link with international postage i would me much thankful.

Eh, i will be tracking the car and driving it hard, so i will just stick with race ones i think! it will be getting very regular oil changes

can anyone confirm that those pistons will work however?
i dont particularly want to waste my money ordering them and boring out my cylinders if they are not going to work.

So, here is some more pictures from the build room. aka my tiny little shed.

Started off looking like this:
https://cimg6.ibsrv.net/gimg/www.mia...a1f4d5d7fc.jpghttps://cimg8.ibsrv.net/gimg/www.mia...2e1e5cec53.jpg
Got everything i was not actively working on wrapped up, or in little plastic boxes/baggies
https://cimg7.ibsrv.net/gimg/www.mia...49d98a4b02.jpg
Painted the block an off-white colour, because why not.
https://cimg5.ibsrv.net/gimg/www.mia...9aa2b60482.jpghttps://cimg4.ibsrv.net/gimg/www.mia...20d002cf75.jpg
And then last night i finished clear-coating my valve cover.
https://cimg5.ibsrv.net/gimg/www.mia...e2d318b3f4.jpghttps://cimg0.ibsrv.net/gimg/www.mia...303660fca1.jpg

EDIT:
Also, what are the opinions on oil pump shims? should i go for the recommended of 2? or just one to be a bit safer?
this will be street driven, not daily, but certainly fairly often.

Im going to ignore all that you said, mostly just want to say welcome back BogusSVO. Been a long time since you have been on. Hopefully things are going well for you.

No name EBAY rods checking in here, came with 3/8 ARP 2000 hardware. lots of abuse. no problems.

Either will work as long as you get the proper bore size.

Keep in mind that Wiseco is a high expansion piston and the ST is a low.

the way I normally get block work done is have the block rough bored to within .003-.005 of recommended bore finish size then order pistons, then have the block finished honed to the pistons and set PTW

Hey Shuiend, All is well, been stuck in the realm of domestics for a while, n missed being on the forums.. so now that things have settled I have a bit of time to cruise around

Interesting... there is a fair price gap between ebay rods and eagle ones.

£215 for ebay "MaxSpeedingRods"
£320 for Eagle rods from fab9 tuning I just worked out with import tax minus shipping.

To be honest I would just feel better paying the extra for the peace of mind!

Ok, awesome. good to know.
yea that is the main reason I am looking at supertec is that reason alone. I have read good things about their expansion characteristics.
cheers :D