Hypothetically.... 1UZ 3.5Ltr

[rivmasta]

Hypothetically... to get a 1UZ down to 3.5 Ltr would require changes to either stroke, bore or both. Im looking to find the best balance between budget and performance for this hypothetical engine.

Hypothetical engine would be <3500cc, absolutely no chance of FI, built for torque instead of HP (offroad racecar), be built to the cheapest form I can do it in.

currently:
bore = 87.5mm
Stroke = 82.5mm
Capacity = 3969.4cc
rod lgth = 147mm
Bore/Stroke ratio: 1.061
Rod/Stroke ratio: 1.770

option 1, Bore Only:
bore drops 5.5mm to 82mm
Capacity to 3486.1cc
Bore/Stroke to 0.994

costs: Sleeves, Pistons, rings, pins, machining.
what are disadvantages/advantages of that bore/stroke ratio?

Option 2, Stroke Only:
Stroke drops 10mm to 72.5
Capacity drops 3488.3
Rod Length increases 10mm to 157mm ***EDIT - should this be increase by 5mm?***
Bore/Stroke to 1.207
Rod/Stroke to 2.014

Costs: Custom crank (or can you regrind 10mm off? Naaa - didnt think so!), custom rods.

What advantages/disadvantages would thais have over doing bore only?

Option 3 would have been both... cant afford that though! (hypothetically of course!)


Would the standard sized valves, runners, manifolds etc suit a 3.5Ltr or would it all be too large losing any advantage over my opposition I may have?


Just out of interest..... probably.

 

[Zuffen]

I'd look into whether you can hard weld and regrind the crank. I know cranks can be welded and ground to save one that has suffered damage.

If that can be done I'd destroke the engine. Custom rods could be a bit expensive but have al ook around for the right length rods. Little end size is easy to fix and if the rod had a smaller big end it would mean less crank work.

As you run an aftermarket ECU I'd look at a couple of turbos and an intercooler.

No point in reducing the capacity if you don't force it.

The valves and ports wouldn't be too bad particularly if you turbo'd it.

 

[rivmasta]

hmmm... crank question is an interesting one. Know anyone in Aus or NZ that might hard weld and regrind?

Cant turbo/s.charge it... it'll be 3.5Ltr N/A, so most guys are talking about holden v6's (puke) but If a destroked 1UZ that would develop more tq/hp than a v6 I'd definately consider doing it.

Pls correct me if Im wrong, but reducing stroke by 10mm means that piston height is reduced by 5mm so I need rods 5mm over stock... or deck the block by 5mm which would cause intake mani problems. Is this paragraph correct?

 

[Lextreme II]

Rod,

The above combo can be done for about $3,000 USD. There are many rods out there will work. Custom pistons will be a must. Hardweld and regrind can be done for about $1000. BE or SE will not be a problem at all.

 

[ed_ma61]

why grind and weld?
just offset grind and go a 5mm smaller BE...

also, the ONLY advantage (short of keeping within class restrictions) to go the smaller capacity is the benefit of revving higher so your vol/min (=hp) is the same. this completely contraindicates the idea of keeping the stroke stock and sleeving down the piston dia - crazy talk! must note though, capacity always wins ovr revs - so class restriction had better be the only reason for the loss of cc's. worried about torque - get it back with gearing

its a race motor, not a daily driver so bearing wear from the smaller BE will be a non issue. just keep it well oiled - so so much cheaper and more sensible than hardwelding and regrinding...

2:1 rod stroke ratio would be interesting - you could get away with some hellishly funky pistons with that kind of skirt loading. youll need a vey high velocity intake though - so be wary of choice of intake design

 

[ed_ma61]

and yes - to destroke 10mm you need to offset grind only 5mm, and thats 5mm longer rods. though you could easily squeeze in 5mm offset and 10mm rods as the factory piston compression height is woefully large...

as for crank grinding - practically any decent engine workshop with grinding facilities. NAS automotive in thornleigh comes to mind, but im sure theres lots lots more

 

[UZZ30-Québec]

a 3.5 liter V8 won't make more torque or horspower than a 3.5 liter V6

in reality, you'll have smaller combustion chambers, so you'll have less low-end torque. The positive point of having a 3.5 liter V8 is that with small stroke, you can rev it 10 000RPM. but say goodbye to the torque. Also reducing Stroke lenght will result in having less low-end torque.

If i had 3000$ to spend for 3.5 liter engine with High HP high torque. I'd search for a GR V6 bloc. 270BHP, 260tq just matt it to a manual transmission. VVT-I so you'll have a lot more low-end torque than any other engine, while not sacrificing the high-end horsepower.

Aluminum Block will also be lighter than you aluminum V8 while being more compact.

that,s my humble opinion.

 

[ed_ma61]

you can rev it 10 000RPM. but say goodbye to the torque.

so what do you think the engine is doing at 10000rpm? um, making torque? thats what gearbozes and diffs are for

 

[UZZ30-Québec]

so what do you think the engine is doing at 10000rpm? um, making torque? thats what gearbozes and diffs are for

and you think a 10 000RPM V8 with absolutely NO JUICE beyon 4500RPM will make a good off-road race engine? :veryhappy

try to suit an OEM toyota gearbox with an OEM toyota diff to match a 10 000RPM engine... He's talking small budget, and off-road. He also wants torque. The new GR V6 engine answers all his needs.

Stock, Light, more powerful, compact, more fuel efficient (more laps with less fuel).

I'm not trashing on the UZ, but you can't compare a destroked 1990 conception V8 with a 2005 conception V6 (forget about GM when i say that :lol

 

[Toysrme]

Except that the new GR's are also $3000-5500usd engines.

Why not buy one of Toyota's former v6's? They range from 2L to 3.4L, and if you just *have* to have 3.5L of displacement - the 3L +'s will bore & stroke to it - with a custom stroke kit. Like, other similar construction v6's... They'll hit your 9000-10,000rpm with the supporting mods to do so. (Rods, pins, valvetrain/cam, headwork to flow what the cams want.)

I'm just not understanding why we are taking a 4L v8 that is going to be costly to de-stroke it. When we can have an easier, and cheaper time working with one of the many Toyota v6's avalible & up-stroke one of those???

 

[UZZ30-Québec]

in a junk yard here you can have a GR 3.5 bloc with computer and loom for about 3000-3500$ it's not a front clip of course so no accessories, but you have everything to make the engine work, intake, ecu, loom, manifolds, mosts sensors etc.

More cylinders don,t mean more power.

might cost a litle more in your region, but I still beleive that it's the best bang for the buck, power, torque curve. and these are 270HP factory stock, imagine with some goodies you get the 300HP quite easily and you don,t need to rev it 10 000RPM, so it will work well with stock toyotas trans/diff combos. But still, as i said before, it's only my humble opinion.

 

[ed_ma61]

3mzfe is a pretty decent 3.3L v6 vvti - 3,309 cc 3.3 liters V6 91.9 mm bore, 83.1 mm stroke, 10.8 compression ratio - im sure you could get one of those cheap, bore it out to your 3.5L and do some minor head work...

 

[Toysrme]

Both the beams v6's (i.e. 1mz-fe & 3mz-fe w' vvt-i) cost $2500usd+. And 2500usd being a bargin price. Which is why people stay pre vvt-i if they're on any sort of budget.

If it were me? Set a power goal, and buy either a 3vz-fe, or 5vz-fe & run with it. They're cheap, they'll both run 450-550bhp without cracking for new pistons if you keep fuel in them & they're both as bullit proof as anything this side of a 1uz-fe, or 2jz-gte in Toyota's all-time lineup.

VZ vs MZ is a long debate. As both sides have positives & negatives for stock, non-rebuilt engines.

 

[UZZ30-Québec]

he can't GO Forced Induction.

 

[ed_ma61]

i think youll find the 3mzfe (in non vvti form at least) would be cheap-as over here...

 

[WDoherty]

you could even search for a VQ with a 6 speed already attached. 3.5L, 287hp to start with, 300 for later dual variable valve timing models. Their already 3 or 4 yrs old so should be cheaper and they are know for their torque and response. find a wrecked 350z or g35 and your good to go. just another idea

 

[R-Jay]

no chance of that in sydney, they're still bloody expensive.

 

[rivmasta]

Top debate!

Engine will be rear mounted, transaxle will be a custom built and geared Renault UN5, which means custom adaptor, throw out bearing, flywheel, clutch etc - hence the discussion of the de-stroked 1UZ possibility - we're already getting a 1UZ installed, so it may work out cheaper to mod the setup we've already got.

Ed - found a place around the corner in Seven Hills that can offset the crank without grinding. Mind you, they're just out of the phone book, not a recommendation which I'd prefer!

Although from sounds of things we may find our butts getting whooped if we go with the de-stroked 1UZ by other V6's... which tempts me to ask the next question:

Is there any V6 toyota with the same bolt pattern/flywheel as the 1UZ?

I'll start doing some research into the N/A toyota v6's... I hate operating to a budget!

 

[Zuffen]

Why is forced induction out?

You mention the 1.7 equivalency loading for FI which with 3.5litres makes 5.95litres.

A couple of turbos on the Crown log manifolds would be able to crank out 450hp on a budget.

Turbos would take advantage of the large piston area.

Whilst on a budget an couple of turbo's won't break the bank.

For crank grinding talk to NAS at Thornleigh.

 

[rivmasta]

FI is out because that puts us into the open class - there are now 10+ cars in there worth over AU$250K and more on the way... which is way, waaaaay out of our budget! Average competitive car at a national event would be AU$75K to AU$150K which is stil way too much.

3.5L N.A. is where class 2 (up to AU$100K, but $25K can still be very competitive) looks like going to from 1.6L which between me and the guy I race with we can afford (towards the lower end of the scale!)

boosting it may be an option in the future... when we can afford the transaxle to handle it.

Final decision comes down from CAMS in August/September meeting... 4.0L, 3.5L, 3.0L or 2.0L F/I....

Hopefully 4.0, but whispers say 3.5 so people can boost it as an option an go to open class.

Thanx for the recommendation - do you have any input as to whether a destroked 1UZ would be disadvange or advantage over a 3.5L v6?