20 valve engine conversion, help.

[k10]

Hello all. I have 3 MR2 Mk1's at the moment. One is a track car and I'm considering an engine conversion to a silvertop. I want a bit more BHP and I still want to retain the reliability and the N/A revvy nature for the stock 4age.
What I need to know is the following.
1. What BHp does the silver top 20v actually make in reality?
2. What is the extra weight over the stock 4age?
3. Does it fit straight in without mods tot he engine mounts etc..?
4. Can the gearbox off a stock 4age be used or does the 20valve have it's on box and how easy it it to use this box in a differnet mid engined configuration? As the 20 valves all appear to be out of front engine levin type vehicles..
5. Apart from the engine, box and ECU do I need any other bits to make it fit into a aw11 ?
Thanks a lot
K

[Lauren]

1. 145bhp maybe(!)
2. Doubt there is a significant difference.
3. It will fit straight onto the engine mounts but you need to dick around with the coolant pipes.
4. Yes though the gearing is not perfect, though it's okay.
5. Not really no.

[MartG]

What Lauren says

Quoted power was 165 IIRC, but that would be a new engine on 100RON fuel in Japan, so expect slightly less on UK fuel ( unless you pay £££ for BP Super ). In the MR2 you won't have a cat fitted, so you may gain a couple of bhp back there.

[IanClements]

If you're sticking to N/A wouldn't the black top be a better engine with slightly more power? Considering this myself at the moment.

[Lauren]

If you're sticking to N/A wouldn't the black top be a better engine with slightly more power? Considering this myself at the moment.

I think the trouble is that compared to a 16v it's hard to notice the apparent horsepower difference driving a 20v. I've driven Neil's 20v sprint car in it's various stages of development over the last few years.

I think the problem is we all go 'wow it's a 20v and it's got VVTi', then make the mistake of expecting it to be like VTEC. Well it's not. Undoubtedly the throttle bodies sound good, but although it revs another 500rpm or so higher the tangible benefits of doing so are not very clear when it comes to driving it.

In summary if you are going to do an engine conversion, I really wouldn't do this one as it's just not that amazing compared to a 16v and for the cost is a relatively low increase in power.

[PW@Woodsport]

In summary if you are going to do an engine conversion, I really wouldn't do this one as it's just not that amazing compared to a 16v and for the cost is a relatively low increase in power.

Paul agrees with Lauren in Imoc shocker.

Complete waste of time and money in my opinion, chuck a 2zz in there if you want to retain the revvy 4age nature and it's 190bhp with proper VVti.

A lot more bang for your buck

[cartledge_uk]

In summary if you are going to do an engine conversion, I really wouldn't do this one as it's just not that amazing compared to a 16v and for the cost is a relatively low increase in power.

Paul agrees with Lauren in Imoc shocker.

Complete waste of time and money in my opinion, chuck a 2zz in there if you want to retain the revvy 4age nature and it's 190bhp with proper VVti.

A lot more bang for your buck

Not a complete waste of time, depends on reasoning, but for day to day driving. I agree too

[IanClements]

Complete waste of time and money in my opinion, chuck a 2zz in there if you want to retain the revvy 4age nature and it's 190bhp with proper VVti.

OK, fair enough, how much to do that conversion against the 20v and v6 including parts?

[Lauren]

Complete waste of time and money in my opinion, chuck a 2zz in there if you want to retain the revvy 4age nature and it's 190bhp with proper VVti.

A lot more bang for your buck

DING. Though a conversion I really wish someone would do is put the K20A in there with the six speed box and LSD. It's a much better engine than the 2ZZ in terms of power and delivery. That'd put a smile on your face.

[PW@Woodsport]

Complete waste of time and money in my opinion, chuck a 2zz in there if you want to retain the revvy 4age nature and it's 190bhp with proper VVti.

OK, fair enough, how much to do that conversion against the 20v and v6 including parts?

Any of the "big" Mk1 engine swaps are going to cost £3k to £4k but if you DIY you can half that.

[Neil_turbo]

Hello!

I think i would agree with most of the comments here, the performance increase is relatively small, especially if you are having to pay someone to adapt looms etc. Though does come with the benefit of no welding in new mounts, so would be an easier homebrew conversion

Sound is fantastic off the throttle bodies and revs very well.

I am however removing the 20v engine to replace with a 3SGTE over the next few months so i can have a go at chasing down the bigger power cars in the sprints next year!

[IanClements]

Any of the "big" Mk1 engine swaps are going to cost £3k to £4k but if you DIY you can half that.

Would the 2zz be any easier to fit than a v6? Has anyone actually done one of these yet?

[LimeyMk1]

Any of the "big" Mk1 engine swaps are going to cost £3k to £4k but if you DIY you can half that.

Would the 2zz be any easier to fit than a v6? Has anyone actually done one of these yet?

Physically I think the 2zz would be much easier to fit than the V6. Not sure about how easily the coolant system matches up but that's not insurmountable.

I think there are 0ne or two conversions out there.

[PW@Woodsport]

Any of the "big" Mk1 engine swaps are going to cost £3k to £4k but if you DIY you can half that.

Would the 2zz be any easier to fit than a v6? Has anyone actually done one of these yet?

Yes i've done one, to date the only 2zz Mk1 in the Uk that i'm aware of. It mounted very easily (3 of the 4 mounts go straight in) but there were lots of little things to modify and the exhaust manifold proved to be a right pain.

The big plus is you get a 6 speed box thrown in.

Ultimately the V6 wins hands down in every way though in terms of performance gain if we are comparing them. If you are chasing a big BHP number then 3s-gte is the way to go.

[IanClements]

To be honest I'm more bothered about handling balance and running costs as much as outright power, just need a bit extra for overtaking. It seems that the guys with turbo's (mainly mk2'ers) can't put their foot down mid corner and that spoils the fun for me.

Also I'm thinking I might be able to fit a 20v myself but welding new mounts in for the other engines is a definate no no. Horses for courses, must get myself a drive in a converted car some day.

[PW@Woodsport]

I'm afraid even the 2zz requires one welded chassis mount so it looks like your only option is the 20v. It's just you will spend quite a bit doing that swap and it will leave you very disappointed with the gains.

Without welding any chassis mounts I'd rather go 4a-gte or Sc. The 20v is a pointless swap in my opinion.

The 1mz v6 in a mk1 is sublime, no upset in handling or balance, just loads more power in any gear instantly on tap. Try talking to 1mz mk1 owners for an unbiased opinion.

[kaiowas]

Try talking to 1mz mk1 owners for an unbiased opinion.

Presumably the people who liked it enough to have paid out good money to do the conversion are going to give you anything but an unbiased opinion!

[Bender Unit]

For the cost of doing the 20v you could
tune the 16v and get more power. You also benefit from cheaper parts too.

A friend has just spent a fortune building up a blacktop for his sprint car, his thousands spent has given him 190 bhp, and 10k rpms. Yet its an ar$e to use on the road and will probably need a rebuild at the end of the race season!

[IanClements]

For the cost of doing the 20v you could
tune the 16v and get more power.

I think this one's been covered a thousand times but let's have another go. What would you recommend to get the 16v up to 150-160bhp whilst being driveable (decent mid range), reliable and cheaper than a conversion.

Sorry if I've hijacked your thread K10 but it's all useful info.

[PW@Woodsport]

Presumably the people who liked it enough to have paid out good money to do the conversion are going to give you anything but an unbiased opinion!

On the contrary, it would be all over the internet how bad the 1mz made it feel or they would at least report back to me there was a problem with handling, wouldn't you?

I can assure you a 1mz Mk1 is absolute utopia, i cannot fault that conversion in any way.