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Engine Dilemma
Elmof1 - 26/8/18 at 12:49 PM

Hi,
I've just joined the site as Ive just taken ownership of a part build MK Indy. It had a Ford DOHC 8V fitted, this has now been removed.

So on to engine choices:
Option A - ST170 engine with throttle bodies, ME221 ECU. Possible CAT CAMS VCT delete, as i would be rebuilding the engine.
This option is compatible with my MT75 and prop shaft etc, so i pretty straight forward installation.

Option B - ST150 engine with throttle bodies, Omex ECU. Could probably get away with standard cams, but again will probably give the engine rebuild so cams are an option.
This option would need a MK3 MX5 gearbox, modify prop shaft, exhaust on opposite side.
Also is the height of the duratec and the 10deg install a consideration

I'm aiming for power unit @ 200bhp

I keep flipping between the two. Any input would be appreciated

[Edited on 26/8/18 by Elmof1]


rdodger - 26/8/18 at 01:04 PM

What do you intend to use the car for?

I would be considering that before I made my choice and the best gearbox/gear ratios for what you intend.

A peaky engine with wide or unsuitable ratios won't be ideal.

I would put your choices through a gear calculator before making your mind up.

For track use I would find a 6 speed Caterham box and use that with a cheepish engine that you can bolt a few bits on to to get decent performance.


big_wasa - 26/8/18 at 01:16 PM

The Duratec is the better newer engine but I love a Zetec as I feel they are more durable. The St170 is still a Zetec. They are easy to work on. Good low miles St170 lumps are getting harder to find and a lot are at the point where some one will just run it into the ground sooner than change the oil. The solid lifters are one piece so it’s not a cheap job to do the valve clearances. The top piston ring is differant to a black top and ford stock bugger all for an engine of this age so all the bits will be after market.

If I was starting again I would grab a new crate Zetec. Do the sump and throttle bodies. I would then get the head ported and a set of cams the following year.

The Mt75 is getting very hard to find and has a crap first gear. I still have one as they are nice and strong. but a heavy duty close ratio type 9 will be better suited to a na Zetec.

Again don’t discount the cost of a rebuild on a Duratec.


big_wasa - 26/8/18 at 02:51 PM

Now my dilemma is where is the sweet spot for power ? The engine is easy, Zetec Zetec Zetec.


russbost - 26/8/18 at 04:07 PM

Throw away all the horrible heavy & expensive car stuff & drop a ZZR1400 in - job done! (or, more cheaply a ZX12R)


big-vee-twin - 26/8/18 at 05:55 PM

ST150 comes with a standard flywheel not dual mass, also comes with egr valve blanked.

Use the Ford Type 9 gearbox and will have no angle problems.

Add some Jenvey throttle bodies and megasquirt and you will get 200hp without too much trouble.


perksy - 26/8/18 at 07:08 PM

quote:
Originally posted by big_wasa
The Duratec is the better newer engine but I love a Zetec as I feel they are more durable. The St170 is still a Zetec. They are easy to work on. Good low miles St170 lumps are getting harder to find and a lot are at the point where some one will just run it into the ground sooner than change the oil. The solid lifters are one piece so it’s not a cheap job to do the valve clearances. The top piston ring is differant to a black top and ford stock bugger all for an engine of this age so all the bits will be after market.

If I was starting again I would grab a new crate Zetec. Do the sump and throttle bodies. I would then get the head ported and a set of cams the following year.

The Mt75 is getting very hard to find and has a crap first gear. I still have one as they are nice and strong. but a heavy duty close ratio type 9 will be better suited to a na Zetec.

Again don’t discount the cost of a rebuild on a Duratec.





Good advice from Big Wasa

The Zetec is a solid dependable unit that you can modify as you go along

Decent type 9 gearbox with the correct ratios is night and day over the standard MT 75 gearbox and I'd recommend BGH for a gearbox


sdh2903 - 26/8/18 at 08:35 PM

Or a different way to go. Crate zetec, retroford adapter plate, mx5 nc box. A really good box available for cheap and will take 200bhp all day long

I very nearly went this way until I lost the plot a little and bought a v6.

http://www.retro-ford.co.uk/shop/content/ford-zetec-mazda-gearbox-adaptor-plate-kit-mx5-001

[Edited on 27/8/18 by sdh2903]


Elmof1 - 30/8/18 at 09:13 PM

Thanks everyone for the replies and the recommendations etc.

I've decided to go down the BEC route, as this will be a road legal track day car.

I've seen a 2016 CBR1000RR engine with all the required running kit etc, only around a 1000miles so nearly a new power unit. This model has a slipper clutch, anyone had another experience of on of these in a BEC.

I've watched a few track day footage on youtube and the CBR1000rr BEC look pretty rapid, although a little bit down on torque when compared to a busa.

The Hayabusa / ZZR1400 is another option but generally mileages are higher and or they are going for silly money.

If been reading though Rosco's build below, top quality engineering. Something to aim for i guess...
https://www.locostbuilders.co.uk/forum/50/viewthread.php?tid=194553&page=1