Engine mods

[MART]

Can anyone confirm what my engine rebuilder is telling me , he builds drag racing and race car engines for a living. He said that a 1.3 zuk engine bored 40 thou with the right head and cam combination , while running a blower at 6 PSI can pick up 40-50 kw . The intake manifold and head , head and extractors will be ported and matched to there limit , flow tested and the cam will be ground to a blower grind giving constant torque over entire rev range , approx cost $650 , has anybody ever done this. Also I have read a few threads on blown zuk engines and they recommend to use 8 valves head for forced induction and 16 valve head for normally aspirated engine for performance sake , Cheers and thanks in advance , Paul

[PJ.zook]

Really if youre after a lot more power, you would be better with an engine swap, but if youre like me and want a little more useable power, just do a standard rebuild and make a turbo exhaust manifold, run it to standard intake manifold and run like 5psi.

[Gwagensteve]

A 110% increase in power seems unlikely at 5PSI, but even assuming it was possible, my guess is that part throttle and off idle drivability will be poor with a carby.

I agree that it should be a torquey motor, but I think programmable efi will be required to get this kind of HP with the drivability and reliability you are chasing.

Drag racing tech is not really comparable to what we are trying to achieve.

Just my 2c.

Steve.

[droopypete]

Drag racing tech is not really comparable to what we are trying to achieve.

Just my 2c.

Steve.

I can confirm what Steve is saying here, many years ago I wasted 10s of thousands of dollars listening to the advice of my drag racing/street machine mates (advice that was correct if I was building a drag car or street machine), just about everything is opposite.

as an example, I need a set of leads,
mates say, get these they are 12mm in diameter and it is all about the lead!
I find, wrong! in a 4x4 it is more about the boots than the lead, my mega buck leads (that looked really cool by the way) would shyt themselves at the first sign of water
cams, carbys, radiators, air cleaners, torque converters, fans, it is all the opposite, and the list goes on.

Learn from my mistakes, stop listening to drag and race car people unless you are building a drag/race car, join a 4x4 club with lots of modded 4x4's and ask them what works and what doesnt, their advice is free (and they are not trying to sell you anything).

My advice? chuck in a standard 1.6 and have heaps of fun, (use the money you save on a deposit for a house).
Peter.

[sierrajim]

My advice? .......use the money you save on a deposit for a house.....

....with a really big shed

[MightyMouse]

A little too optimistic I think - with such moderate boost you are unlikely
to double your power.

Dito what Steve says re EFI, but you may find five PSI with a relatively stock motor gives driveability gains.

Give the camshaft work, head work etc a miss, IMO torque is the off road king, brute power is not a whole lot of use.

And ..... If your going to blow it avoid boring it. The bore strength is
way more important than the miniscule gains you will bet by overboring.

Small jap engines sleves are often unsupported or poorly supported at
the head end, and tend to move when used hard ( don't actually know
about zook but keep in mind ).

I you can do this yourself, then it sounds like fun - but if your paying to
get it all together then I wonder if you understand how much it
could all cost . A set of forget pistons and rings will set you back well
over a grand and that's just the start.

[Gwagensteve]

Ross, it wasn't really the effect of the boost I was questioning, only that on a carby motor or poorly tuned efi motor with boost that the drivability will suffer (more due to compromises in timing and fuel control)

Our '05 cooper S runs relatively low boost and has very broad drivability and lots of midrange torque, but also very sophisticated timing and fuel control, which only the very best aftermarket injection would get anywhere near.

Drag racing tech tends to prioritise HP at the expense of anything else becaue that's all that matters for that application, so carbies and even mechanical injection can work fine for what they need to do.

Fine throttle control, off idle throttle reposonse and behaviour at light throttle are all far more important than outright HP, which is why A) turbo petrol motors are unpopular for off road work (he says, with one in his shed ready to go in ) and 4WD motors tend to have low specific output (hp/l)

Steve.

[MART]

Thanks guys for the response , I do have fuel injection , but only throttle body and 1 extra injector for boost. With regards to the cam he said a blower grind will increase torque down low and also through the rev range. I only have a standard pistons as forgies where about $1600 as no other piston apparently fits. The engine is bored 40 thou due to previous blowup and according to his book of specs the 1.3 block can be bored up to 100 thou , is this right as I also read the info in his book because I didn't believe him. So from what you guys have said doing head work and changing the cam will be no benifit , Cheers and thanks in Advance , Paul.

[Gwagensteve]

At low boost, and for low RPM, I would have thought it would be hard to go past (and difficult to improve on) the stock cam.

Personally, a think the $650 would be better spent on some propper EFI gear and tuning- I'm not knocking the throttle body in itself, but I think that getting the air/fuel and timing control spot on with a supercharger is pretty critical because they can achieve high piston loadings at low RPM which is the worst possible condition for the motor (if my limited understanding of such things is correct)

Do you know whay your last motor failed? Detonation?

Steve.

[Spike_Sierra]

rings melted from memory...

[Gwagensteve]

Detonation then....

I would make sure it is tuned on a dyno. If you can't get enough control with the TBI don't push it - go to MPFI and a programmable computer.

You will need to control timing so maybe a coilpack Jimny head would be the go.

Don't know what they are worth but assuming a good condition bottom end a stock jimny is good for 59kw, so you already have another 12kw before you tip any boost in, and ability to properly control fuel and importantly timing.

Getting timing out of the car (and enough fuel in) under boost/low revs will be critical to making it hang together.

Regardless of head and cam work you'll need to spend plenty of time on the dyno to get the bottom end right.

Just my 2C

Steve.

[droopypete]

I would make sure it is tuned on a dyno.

go to MPFI and a programmable computer.

so maybe a coilpack Jimny head would be the go.

you'll need to spend plenty of time on the dyno

Just my 2C

Steve.

2c??????
I would say it is more like the cost of a 1.6 just in those items.
Peter.

[shw337]

sry to imbarge on this thread, but from readin what has been said, i hav also been askin guys at work about turbo or supercharge my new 4age that is to go into my seirra as the current one has blown piston rings (due to running to lean i belive, but maybe somthing else). altho i wont be adding either turbo or superchager until later, wat is the better option for 4x4, blower or turbo, at low psi.

[ofr57]

both can be used
big patrols usally put turbos on ... an i know some zooks with small turbos so they kick in quick

but still i favour the blower

[Gwagensteve]

i hav also been askin guys at work about turbo or supercharge my new 4age.

They already come supercharged.... 4AGZE. Just put one of those in. Better ring design, oil spays under pistons, lower comp etc.

Yes, you could supercharge/turbocharge a 4AGE, but when the right motor is available already boosted, why would you bother?

A whole 4AGZE would cost less than boosting your motor properly even before you built you motor for boost.

Steve.

[oldcrusty72]

i know this is a diferent engine and diferent car but I had an 85 pajero a few years ago, the engine was stock 2.6L 4cyl. I fitted a Garret T4 @ 15psi to it and used a dirty great big SU carb on it. It had great throttle response all through the rev range, i have no idea what the HP was but i had 31/10.5R15 desert Duelers on it and thanks to Mr LSD it would light up both at the drop of a hat if you hit the throttle. Totally different set up as i said but don't discount using a carby. Efi will always be better, but also cost more too. I spent about $1200 to fit it all up myself that dosent include the turbo cost, i already had it sitting in the shed. The only labour cost was getting a guy to fit carbon seals to the turbo to run a draw through carb setup. I've always regretted selling that car, but then i if i didn't i wouldn't have my zuk which i enjoy just as much.

Oh yeah as you guys know don't try and put 15psi into a stock zuk engine, the Paj compression is about 8.5-1 stock so was happy with it.

My personal preference for a 4x4 would be for a supercharger setup as it gives more consistant torque at all rpm's, yet i'm still planning to turbo the Baleno engine i have in my Zuk,


Tim

[MightyMouse]

Yep a 4AGZE would be a good - low pain option.

Steve - wasn't questioning your musings, I sort of skipped between
a number of the previous postings without warning.

IMO Supercharging or Turbosharging can both work well - but it depends
on deciding exactly what you want at the beginning. This will affect
blower size, drive ratio etc or turbo A/R ratio and trim.

You can use small turbo's and get good low end response but at the
cost of top end restriction and in worst case - failures. Larger A/R's
tend to be the other way around and give the dreaded.................lag.

Most OE blowers on the other hand tend to start running out of puff
towards the top end ( sized that way ) and so can feel quite different
to a turbo car.

But what is a known is that a badly engineered turbo or blower, poor
mixture and timing control can turn even a great engine into a PIG,
or scrapmetal. Your more likely to be satified if your realistic and a
bit conservative. Using what an OE has spent man/years getting
right is much less fun but a lot more certain.

[shw337]

only reason im running another 4age is becoz i want the zook back on the road quickly, and i got the new motor,clutch, box n uni-chiped ecu, at a price that felt like stealing.. and was planning on turboing the old motor once rebuilt. been readin up n a smallish turbo running 6psi or sumthing shudnt do to much damage and run fine for an acceptable amount of time.

[Gwagensteve]

You might be right, but I guess the key factor here is what constitutes "too much damage and run fine for an acceptable amount of time"

You might be fine, but it will depend very much on the quality of the installation and the quality of the tuning.

4AGE's run fairly high specific output in NA form which is part of the reason why when toyota redsigned the motor to take boost they made some pretty big changes.

I don't think that you could get a turbo on a NA 4AGE and get it tuned for less money than a complete 4AGZE.

Just my 2C

Steve.

[MART]

So Steve , do you reckon opening up ports on head and changing cam won't increase power and torque , also I have read that most engine's including 1.3's can handle 6 pound boost and have no problem's as it is less than 1 atmosphere in pressure in the standard bottom end , do you know if this is true or have you heard this before , Cheers Paul.

[droopypete]

I am a bit confused, you are asking advice on how to do it, yet your sig line says you have already done it (even got the number plate) what gives?
Peter.

[MART]

I do have it , A TBI 1.3 Supercharged engine , it got hot due to too much boost , about 15-17 Pound , The piston glands broke and this caused the no-1 piston to slightly melt. The reason it broke is it was under fueled and poorly tuned , I spent 9 weeks trying to get a forged oiston to fit but there isn't any out there unless you go custom , $1600 dollars , so I have found out that I can run 6 Pound on a slightly better brand piston so I am changing my pulley speed to lower the boost , hence I was wondering if anybody had done head work and had a blower grind cam in there engine so I can get it right because the engine builder sais that he can raise the power/torque 40-50 kilowatts and I was after people's opinion's and experience's. Every other engine if you do headwork and change cam , ETC the engine perform's better , so why won't a zuk engine perform better , Cheers Paul.

[mrRocky]

you guys need to take into account the added heat being introduced into the system and wether you will be doing lots of sand driving.
ive had a fair bit of experience with turbo cars and the consistently high revs of driving in sand will cause all sorts of heat soak and other cooling issues even with a big intercooler. the 4agze supercharger would be my pick as it ca be switched on and of via a switch if so desired, thus allowing you to control heat alot better, even superchargers heat up a fair bit

[MART]

My supercharger came of a car where the supercharger ran of a vacuum switch and didn't activate until about 2000 RPM , so yes it can be switched off and there is enough airflow through it that it that it doesn't affect the motor without it on , so when the car is idling there is no boost , this is how I am going to run it , also a blow off valve set at 6 pound , plumbed back to airfilter as a closed circuit , also the engine runs on half with the blower going , Cheers Paul.

[MightyMouse]

Unless you have done something strange the SC14 has not only an
electric clutch control - but also a vacuum operated air bypass around
the blower when its not operating.

If you can pull enough air through a stationary blower that the
car can run to 2000 RPM then the blowers stuffed.

[MART]

Mighty mouse , where did you come by that info , Cheers Paul

[=SKB=]

With respect for the rig you have built so far MART, (and obviously the $$$ involved), why muck around with the 1.3? Why not go all out and fit a 4agze or a turbo 1.6 maybe? I realize you might want to work with what you have already got, but surely the outlay on a new engine would be better then the dollars (and stress) involved in chasing power from the 1.3. I think something with genuine HP would really top off your rig.

[MART]

With the 1.3 , it will spin all 4 wheels in low range on rock at 2-3000 RPM. This is not my problem , it is on road , if I can pick up 15-20 % more power which I know is possible , It will be fine and I can't work out why people keep saying you can't. It will do 110 on the flat and drop to 90 on moderate hills. If you do a bit of engine work , the 1.3 would be fine with the gearing I have. It does this without the blower so it should be better with the blower. I was under the impression that the way an engine works is air/fuel ratio , so the better the airflow , the more fuel that can be pushed into the cylinder. A blower grind cam supposedly keeps the valve open for the maximim time , to allow for maximum air/fuel into cylinder , I have been in sierra's with engine work and they go heaps better. I was just after info on what other people have done. As for the money I have spent , Is $56 dollars a week for 5 years , apart from a couple piece's , I have made everything myself , the pipe , paint , were free , so you get a little pissed off when people say BLING BLING , like fark , yes I did consult people with the know how but anybody can do that , people are approachable and they will offer info if you ask so if anybody has done engine mods I would like to hear there input , Cheers Paul.

[=SKB=]

I meant the money you would spend on the 1.3 to get what you are after - i.e. the $1600 worth of pistons you have already pointed out, not what you have spent on your rig's construction. I know you have done all the work yourself and on a budget so calm down. I am not knocking your plans at all for the 1.3 but as most would agree the EASY option is to go for a bigger engine. Most of the builds on here usually discard the 1.3 for a Vit engine with the only (usually) mods done to the 1.3 are webber/exhaust/extractors etc.

In saying all that - Do what you want

[MART]

NO worries SKB , not having a go at anybody , but surely there must be one person on here who has done something similiar , so I guess I'll give it a go and see how it goes , as for the blower , with current pulley speed roughly one to one , 28 pound of boost at idle and those tubes on the blower run at the same pressure as the output of the blower to avoid blowing seals out , and the original car it came off which was a 6 cylinder , 2 litre on idle and up to 2000rpm , didn't have the blower engaged , once over 2000 rpm it would cut in. What happens is the blower vains spin even when the clutch is disengaged , Cheers Paul.