economical engine for my viva- suggestions/advice please...

[Taistorm]

If you're interested in heading in that direction you should talk to Mark at Lynchbuilt Engineeriing. He's played around with them a bit and is putting one into his Datto 1200.

[JoKer]

But someone told me honda engines, except the s2000, rotate anti clockwise? If true I'm guessing thats why they have not been adapted to be used in rwd cars?

this is true : seen on in random pic thread within last 20 pages that a guy made his own cams to run it the right way!

or flip the diff/not simple job sometimes

[yoeddynz]

I had thought about diesels ages ago- sadly they are almost always very hefty little things, pricey and not many smaller ones to suit RWD applications. THe other thing is that NZ govt still has not seen the light about diesel cars and makes us pay silly high RUC charges. Not that it would matter if I had a switch etc on the speedo cable..

The above nissan engine looks good Brad- although yeah- the cam angle sensor out back would be a problem hard up against bulkhead.

I have read up some more on the mazda kl v6's. sound great but sadly again they have a silly big cam angle thingee out back.

Some good reading here on them- talk of some F1 version? (16,000rpm)

Hi

Engine Architecture

V6 Configurations

The V6 configuration appears in 1.8, 2.0, 2.25 and 2.5 litre displacements.

2.25 V6 - worlds only Miller-Cycle (MC) as opposed to Otto-Cycle engine. The Miller Cycle uses an 8 to 1 compression ratio with 10 to 1 power ratio for improved power & reduced fuel consumption. The MC uses a twin-intercooled Lysholm-screw Autorotor supercharger (world's most compact & most efficient) to deliver 210-230lb/ft at 3500rpm and 0-60 of 7.9secs from the 4-speed ATX. It effectively achieves the power of a 3.2 - 3.5 V6, yet fuel economy of a 2.1 V6. The 0-60 time through torque-converter slippage masks the accelerative capability.

V6 Block

2.5 V6 - two variations of the 2.5 V6 exist, KL for ex-Japan, KL-ZE for within Japan. The KL is a detuned variant of the KL-ZE offering power and fuel economy of a 2.2 V6 (based on the 2.0 V6 output). The KL-ZE offers 200bhp and achieves up to 94bhp/litre.

All V6s - all Normally Aspirated V6s feature a Variable Resonance Intake System (VRIS), the same concept as later used by Porsche on their 3.6 and Ferrari in much more sophisticated form on their V12. VRIS first appeared in Mazda's in their older 158bhp 2.0i-16 UK engine in 1989, it's purpose is to maximise the area under the torque curve rather than peak figures so aiding low-end driveability. In addition, the VRIS aids fuel efficiency and averages of 27-29mpg (Imperial) in urban driving and up to 32-34mpg (Imperial) on the highway readily attained.

The I4 engines are special derivatives of the Miata & 1.8 I4 235bhp turbo engines. The V6 has been used in the SuperTouring Mazda Xedos6 & 323 V6 5dr (Xedos6 floorpan, not related to the 323), and by Ford in 2.0 V6 form in Mondeo/Contour. The Mazda V6 is not related to the Duratec engine which lacks a forged crankshaft. The 2.5 V6 MX6 raced in several countries successfully. The IMSA 2.5 V6 engines produced 430 - 480bhp from the 2.5 V6, the 2.0 V6 was 380 - 420 bhp, all in race only form.

Engineering Data

Mean Piston Speed

* V6 Engines - all-alloy DOHC 24V 60-degree V6 configuration

* Split Crankcase - as 911 flat-6 offers increased rigidity over traditional bearing-cap solutions for high-rpm capability (7800rpm 2.0V6) and low NVH (winning 1992 German engine award)

* Bearings - 4-bolt Mains, with a further pair of bolts at each bearing section. Key journals & bearings are oversized regarding width. Bearings are triple-layer heavy duty

* Crankshaft - Forged, nitrided, triple-lapped, mirror-finished

* Piston Squirters - Upper bearing journals contain piston oil-squirters to aid cooling

* Exhaust-Valves - Stainless steel & sodium cooled

* Pistons - Lightweight to reduce reciprocating mass, piston skirts are moly coated to reduce friction

* Head Gaskets - Stainless steel is used, with torque-to-yield bolt

* Stroke - Very short stroke creates low crank angles & low rod/bearing loads

Engine Dynamic Stress Levels

Mean Piston Speed, MPS

* 2.5 V6 MPS = 0.167 * 2.92 * 7000 = 3170 ft/min at 7000rpm

* 2.0 I4 MPS = 0.167 * 3.62 * 6500 = 3929 ft/min at 6500rpm

* F1 engine MPS = 4519 ft/min at 16,400rpm

As a benchmark, MPS

* under 3,500 ft/min - Good reliability

* 3,500-4,000 ft/min - Stressing

* over 4,000 ft/min - Very short lived

Bore & Stroke

* 2.0 Bore*Stroke of 83x92mm (3.62" long stroke)

* 2.5 Bore*Stroke of 84.5x74.2mm (just 2.92" stroke)

* For comparison F1 engines have 70x42mm (1.65" stroke)

Ring Loadings Top-rings must balance high-rpm capability and wear, a thin ring allows high-rpm capability, too thin and wear becomes an issue. With reduced crank angles from a short stroke ring wear is reduced. A 1.5mm ring is beneficial over a 1.0mm ring for high-rpm.

Maximum-Piston-Acceleration (MPA):

* 2.5 top-ring - 1.49mm/0.06"

MPA Permitted = 77,000ft/sec^2

MPA Experienced = 51,354ft/sec^2 at 7000rpm

* 2.0 top-ring - 1.17mm/0.046"

MPA Permitted = 105,000ft/sec^2

MPA Experienced = 70,157ft/sec^2

The BMW M5 in comparison experiences MPA of 90,000ft/sec^2 on a 1.5mm ring.

Lighter rings create reduced accelerative forces, reduced ring/piston interface overheating and reduced hammering of the piston-ring-groove. Too light and ring longevity is adversely affected.

MPA = (rpm^2 * stroke"/2189)*(1/2A), A = ratio between rod-length-between-centers to stroke.

2.0 rod-center-dist = 135mm; stroke = 92.0mm; A = 1.47

MPS-2.0 = (6500^2*3.62/2189)*(1.2*1.47) = 51,354 ft/sec^2

2.5 rod-center-dist = 138mm; stroke = 74.2mm; A = 1.87

MPS-2.5 = (7500^2*2.92/2189)*(1.2*1.87) = 70,157 ft/sec^2

Both the 2.5V6 & 2.0I4 engines are engineered for longevity. The 2.5 engine is likely to be the longer lived engine subject to identical maintenance to the 2.0 engine. Mazda V6 engines are assembled entirely by robots, not humans, at the Osaka engine plant in Japan alongside Rotary engines.

Ford bench testing, with very minor changes, showed the V6 to be capable of continuous running at 8900rpm - well beyond redline 7500rpm.

SAE paper "SAE920677" covers detailed design of the engine.

Engine Longevity

Long Term Testing

A USA oil company researched engine longevity using their own oil :

"After 300,950 miles the Mazda MX6-V6 passed an IM 240 Exhaust Emission Test in Aurora, Colorado, with results well within new car limits. At more than 310,000 miles, the test engine was disassembled for inspection and measurement. No wear was evident on valve stems and guides, main and rod bearings, crankshaft main and rod journals, or cylinder walls. The cylinder hone marks from original factory machining were all clearly evident. While piston skirts showed no wear, piston rings showed an average of only 0.0015" of face wear."

The V6 rivals the Lexus V8 for longevity, which is unsurprising considering the original application was a Xedos6-2.0V6, Xedos9-2.25/2.5V6 & Sentia rotary luxury lines. Many V6s & I4s have exceeded 350,000 miles, the only failures on one was a Mitsubishi alternator at over 200,000 miles and the pre-Jan-1995 rear calipers on another.'

This holden ute looks to have a fantastic install of one.

http://gallery.oldholden.com/ReaperHR/OtherHrs/AntsHR/

Looks like they can handle big power but also looks like they might not be the cheapest on fuel either. I need to ask about- perhaps probe a probe owner...

[- i5oogt -]

if you went down the opel engine route theres a manual 4 cylinder VN commie (Gearbox donor) at pickapart in christchurch

[sr1600]

Looks like they can handle big power but also looks like they might not be the cheapest on fuel either. I need to ask about- perhaps probe a probe owner...

Radisich Telstar Engine ?

I think they are,they go well and there nice and smooth.

But id be interested to know gas milage (vs the rotary) as I dont remember the telstar leaving the flat driveway that much.

What about the setup Mjrstar is pulling from the mx5

[yoeddynz]

Flat driveway?

I have put in an 'interest in engine' on matts thread. Cheers for heads up.

Problem with fingpding out about economy is that some engines in certain cars just beg to be caned all day long so hence economy suffers. If the same engine was fitted into something with shitty handling and bland dynamics then maybe it sees slower driving and better figures.

I should have a browse on some of the fuel economy forums etc...

[Rookie]

Honda K Series spin the right way and are cheap it you get the big block out of a van or some shit. Dude in Chch has made a bell housing casting to mount it to a w series too.

+ 1 for diesel.

[KIRK]

renesis all the way. should get less than 10l/100km in a viva

[yoeddynz]

Problem with renesis is in order to get the top mpg you have to have what must be one of the worlds ugliest induction manifolds. Plus they ain't that cheap to buy here. I have a friend who owns us oldest Mazda dealership and he has about 10 engines sitting on the floor after strip down to assess warranty claims. All fine though- carbon build up from Mazda uk insisting customers used the same synthetic oil used in the piston cars (should only be using mineral if car still has oil metering system for tip lubrication) till Japan realised what was up and told them off. Cost company many pennies.

But I digress.

Really liking the idea of the Mazda engines so I can keep my gbox. I think I'm correct that the mx5 bell housing fits onto my 12a box? If so I could look at the v6, a bp or bp turbo.

The v6 engine would require me cutting a box shaped hole in the bulkhead to suit the rear facing cam angle sensor. Plus the overall width might be too much and drivers side cam cover could hit the brake servo (which I want to keep as the brakes are nice the way they are)

Seems that from some browsing a kl v6 is about the same if not only slightly heavier than a mx5 engine.

Which in turn is bugger all heavier than the rotary.

[KIRK]

yes i agree get a 6 port renesis with a 6 speed gearbox. ok done. lock the thread

[77magnum13hundy]

Euro - Vectra engine turbed or non turb'ed with a commy box behind in use the 'a' version block and the 'b' version twin cam head.

Jap - 4age turbo, find a gze block, gearbox is many do-ray-mees.

- front cut siliva sr20de/det complete with engine box loom, spendy-ish...

Or big 6 commy 3.8 v6

my 2c's

[sr1600]

renesis all the way. should get less than 10l/100km in a viva

Im all for this idea, Imagining the viva doing 9000rpm up the passing lane with the bikes/rack on the back.

[glen]

prehaps, convert the current rotary turbo engine to efi ? should improve driveability and overall fuel ecconomy.

or put a sportsbike engine into it.

[flyingbrick]

from my experience... rx8s feel gutless and are too smooth/ sewing machine like.

just my opinion but I think they lack character in their factory supplied state.

yup!!! hayabusa motor with a turbo!!

[yoeddynz]

Renesis just too expensive and still not very thrifty. Owners at the very best are getting 10L/100km when sitting on the highway. I can get that in the viva. I want better.

[KIRK]

convert your current engine to lpg

[Borgweiser]

The correct answer is leave as is, get sweet seventies two stroke death bike. Attach to back of house bus, leave Viva for dorts

economy is for old people and socks and sandal brigade.

[sr1600]

Renesis just too expensive and still not very thrifty. Owners at the very best are getting 10L/100km when sitting on the highway. I can get that in the viva. I want better.

I wonder how much difference injection would make, would look sweet with a series 4 manifold on it.

Id be leaning towards sr if i were choosing a piston but im biased

Alloy block maybe sr20de+t for starters but there seems to be alot of success vs destruction stories out there of people pushing to far.

Im still convinced there is alot to be gained with pre turbo water/meth injection high compression setup like that but i just dont have the money to research it.

[yoeddynz]

economy is for old people and socks and sandal brigade.

And the problem with socks and sandals is?..... (warm and dry yet can breathe though not ideal for when it rains while watching a sweet LH526 trundle by on the main trunk line)

So just now because I have Monday's off and it's raining I have spent much time pondering. Then we both went to a good local wreakers and they have the 2litre Mazda v6 in stock. $400. Looks sweet. We measured it up and it's no more than 21" across the cam covers. Forgot length. But a quick measure up in bay looks like it'll just clear the servo. I can move servo about 1" further away.

The guys there seem quite keen on rotaries with two of them owners of said keg engines. They all cried when I said its gonna go. It hurts me too. But boy the thought of the sweet v6 has got me a bit wet..

They'll lend me the engine. I'll take it to work and do some more measuring. Otherwise I'm leaning towards the 1.8 mx5 engine with a hair dryer.

[SHGWAG]

Have you considered a 2ZZ?

But in all seriousness, you could just try injection on the current engine.