NA builds. How far to go?
08-24-2018, 08:31 PM
Post: #1
NA builds. How far to go?
Hi all.

So in a few months ill be taking my engine out as it needs a refresh and I'm after some more power. I'm looking to stay 16v and go ITBs. I've had a read over Bill Sherwoods page about power build but wanting to get some feed back from people that have gone for power and more up-to-date info.

I'll be forging the bottom end and putting the compression ratio up but not sure what to do with the head work and getting mixed feedback, The head i'll be using will be a blue top and most likely be going for a Link ECU. I'm wanting to aim for a min of 160hp.

Cams are a sure thing but no idea on what size to go for. Would you uprate the valves springs and over size the valves or just replace with OEM parts. Some people say that OEM valves and springs will be good for 180-190 others say that they need changed at 160hp.

Also, Has anyone done a power build on a 3 rib block and 40mm crank? A lot of people say go 7 Rib and 42mm but I'm not seeing any bad evidence against the 3 Rib.

Car is a road legal car that only gets use at the weekend and a few trackways a month.

What have you done and how have you found it? I don't want to find that i've replace/uprated and to find that its having negative effects more than positive.

Thats my ramble for now. Any help would be great!
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08-24-2018, 10:49 PM (This post was last modified: 08-24-2018 10:52 PM by Bean.)
Post: #2
NA builds. How far to go?
I would go for headwork. Have a look at threads from oldeskewltoy.
Going beyond 160 can get costly quick.
Also a lot of the exhaust headers and system available are made for powerfigure upto 160 or 200+. This is mostly du to the fact that to get 180 is the same 'cost' as 200 and more (almost everything will need changing or work).
40mm crank is fine as long as you keep the revs down (below 8k).
Stock valves will also be fine for 160.

As you still intend to keep it on the street I would stick to some mild cams. As it will be a lot more drivable than wild ones.
With this engines pushing the power to the limits = loosing low end torque.
Staying within sensible figures will likely result in more fun.
Somewhere burried in here there are some dyno graphs http://www.aeu86.org/forum/Thread-Surreptitious

Happy hunting.

Sent from my MHA-L29 using Tapatalk

EDIT: only reason to go for ITBs is sound, you wont get any performance out of them in 9 out of 10 cases and more likely to loose torque.

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08-25-2018, 02:03 AM (This post was last modified: 08-25-2018 02:04 AM by oldeskewltoy.)
Post: #3
NA builds. How far to go?
kazi Wrote:Hi all.

So in a few months ill be taking my engine out as it needs a refresh and I'm after some more power. I'm looking to stay 16v and go ITBs. I've had a read over Bill Sherwoods page about power build but wanting to get some feed back from people that have gone for power and more up-to-date info.

I'll be forging the bottom end and putting the compression ratio up but not sure what to do with the head work and getting mixed feedback, The head i'll be using will be a blue top and most likely be going for a Link ECU. I'm wanting to aim for a min of 160hp.

Cams are a sure thing but no idea on what size to go for. Would you uprate the valves springs and over size the valves or just replace with OEM parts. Some people say that OEM valves and springs will be good for 180-190 others say that they need changed at 160hp.

Also, Has anyone done a power build on a 3 rib block and 40mm crank? A lot of people say go 7 Rib and 42mm but I'm not seeing any bad evidence against the 3 Rib.

Car is a road legal car that only gets use at the weekend and a few trackways a month.

What have you done and how have you found it? I don't want to find that i've replace/uprated and to find that its having negative effects more than positive.

Thats my ramble for now. Any help would be great!

Hmmmm, saw(read) you put a "high torque" engine in.... before we make a whole bunch of recommendations, do you have a dyno print out, and a current list of modifications for the current engine?

160hp, or 160whp??? The former isn't all that hard, or expensive, the later is significantly more money, and requires some careful building.


What is your budget??


You can make power on a 40mm rod journal crankshaft, you want to do it before 8500 rpm (sustained rpm - before 8000) Easiest way to retain 40mm rod journal crank and keep piston option high would be to use Molnar 40/20 H-beam rods ($450 ish per set)

Without going into a long winded description, the earlier crankshaft's counter weights are not all "equal". This inequality can lend itself to a torsional difference that becomes evident @ , or around 8500. Careful balancing can protect the crankshaft, but if your goal is a 9000 rpm engine you want to begin with a large (42mm) rod journal crankshaft. Or better yet a $3500+ Formula Atlantic crank

Now, this inequality has an advantage... less mass. The 40mm rod journal crank is over a kilo lighter. Add in the rods I mentioned, and a quality light weight flywheel, and the engine response will put a smile on your face.

ALWAYS new valve springs (with a few exceptions). The stock valve are plenty for 160crank hp, and are acceptable for 160whp (REQUIRES proper headwork).

Cams would be required for either 160 crank hp, or 160whp.

Dan -

You can |Sad .... OR you can ask for help!!!

OST Porting service - http://hachiroku.net/forums/showthread.php?t=19991
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08-25-2018, 04:30 AM
Post: #4
NA builds. How far to go?
What he ^^^ says Smile 160 hp at the wheels takes a bit of effort and careful
planning. I can't speak for the 3-rib engine but I made 130 hp at the wheels on
a Dynapack with an unopened 7-rib with a few bolt-ons, 272 deg cams, AE101
ITB's, stock cast iron exhaust manifold, 2" exhaust and aftermarket ECU with
a DIY on the road tune.

I was aiming for 150 hp at the wheels, and might have got there with a decent
set of headers, a 2-1/4" exhaust and a proper dyno tune. But a bunch of stuff
got stolen out of the car including the ECU, so I'll never know what it might have
done on the dyno.

The 4AGE is a small engine and you need to use every trick you can discover to
help it make torque. Otherwise you will finish up having to rev the crap out of the
engine to have any fun. No problem on the track, but it gets a bit tiresome on
the road.

Cheers... jondee86

The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.
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08-25-2018, 09:52 AM
Post: #5
NA builds. How far to go?
Ideally I’d like to sort the “lack of torque” at low and mid range so I’m not having to really kick the balls out of it either on the street or track to be going anywhere. As for RPM goals, 8.500 is ample I would say, over that would be bragging rights at the pub!

As for cost, I don’t have a budget. This will be a long term build and want to be able to buy the best quality parts that I can afford. No point trying to cut corners on parts and do it on the cheap.

Interesting info on the crank

Also the hp figure I’ve said ideally want to be WHP.
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08-26-2018, 12:39 AM
Post: #6
NA builds. How far to go?
If torque is what you want then you may want to consider a 7A or forced induction

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08-26-2018, 10:15 AM (This post was last modified: 08-26-2018 10:20 AM by jondee86.)
Post: #7
NA builds. How far to go?
This is the torque curve from the engine I mentioned above...

[Image: AEU86 AE86 - NA builds. How far to go?]

As you can see the ITB's did not kill the bottom end, but this
is a smallport engine which is more "torquey" than a bigport in
stock form. On the road it would lug down to 2000rpm without
protest, so no problem driving in traffic.

Torque peaked at just under 6000rpm and power at 7200rpm.
Stock untouched bottom end and stock head. TRD valve springs,
lightened flywheel, second hand cams, custom DIY intake manifold
and velocity stacks, self tuned ... a budget build Smile But it does
show the potential of the AE92 smallport engine. Mine had around
85,000km on it when I bought it from a wrecking yard.

If you are determined to use the bigport engine, then you need
to track down an experienced engine builder who knows the 4AGE
engine and what it takes to make it fast. If in doubt, ask around
the rally community as they have built and broken more 4AGE's
than anyone Smile

Cheers... jondee86

The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.
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08-26-2018, 06:01 PM
Post: #8
NA builds. How far to go?
With a small displacement, and numbers acquired from many different sources.... the numbers can get a bit confusing.... Why don't we include conversion factors...

Newton-meters to foot pounds: ft-lb = Nm * 0.73756 (Nm = ft-lb/0.73756)

HP to PS: 1PS = .986hp (1HP = 1.0143PS)

Dan -

You can |Sad .... OR you can ask for help!!!

OST Porting service - http://hachiroku.net/forums/showthread.php?t=19991
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08-27-2018, 12:18 AM (This post was last modified: 08-27-2018 12:32 AM by jondee86.)
Post: #9
NA builds. How far to go?
I guess what I was trying to say in my previous post (but didn't spell
out) is that your power goal is not out of reach with a bigport engine.
Both engines have the same bore and stroke. The smallport has more
compression from stock and the port sizes on the heads are different.

Many people consider that the bigport head is better for high power
applications, and it is not difficult to bump the compression up with a
set of pistons. A good porting job will allow more air into the engine
and a decent set of headers will help get the exhaust out.

Cams with the emphasis on lift rather than duration will make more
torque and power while keeping peak power within your rev range. And
of course a fresh bore and hone with new pistons and rings will always
work better than an engine pulled from a wreckers yard.

The compromise you have to consider is the balance between power
and torque. This will be influenced by throttle size and manifold design.
A smaller ITB (say 42mm) will give better throttle control and better
low end torque, but a larger ITB (say 45mm) will be better for top end
power. The overall length of the intake from trumpet mouth to valve
head is also a key factor in getting a good result from ITB's.

So yeah... plan it out on paper. Talk to people who have been down the
same path and had good results. No sense in reinventing the wheel with
a high power 4AGE... it has already been done 1000 times by others Smile

Cheers... jondee86

PS: Here is a link to something worth reading...
https://motoiq.com/extreme-engine-tech-t...oyota-4ag/

The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.
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08-27-2018, 05:55 PM
Post: #10
NA builds. How far to go?
(08-27-2018 12:18 AM)jondee86 Wrote:  on the heads are different.

Many people consider that the bigport head is better for high power
applications, and it is not difficult to bump the compression up with a
set of pistons. A good porting job will allow more air into the engine
and a decent set of headers will help get the exhaust out.

PS: Here is a link to something worth reading...
https://motoiq.com/extreme-engine-tech-t...oyota-4ag/

See this is the conflicting thing I’m seeing. On one side people say the small port is to small to make big power and that the large port is actually to large. I’ve seen a lot of people going to small port to then get it ported and polished to get it bigger and saying that’s the way which I find almost counter productive.

Other side

Big port isn’t big enough and needs to be ported and polished to enable good power figures.

Even when talking to people and companies that have done NA power builds with good numbers as an end result with good low-mid torque and power band, there option as well as parts used is different to one and other. It’s a bloody minefield!

I’m going to reach out to some of the rally community and see what they have been doing. I’ll also have a look at that like on my break!

Cheers all
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