9age worth the $$$

[Matt]

Now that there have been a few 7a stroker or 9age kits out on the market, I thought I'd generate some discussion as to what you think of the kits there and if they are good value for money.

I have my opinons of them and that, but I thought I'd keep them to myself and give others the opportunity to discuss them in depth first.

Cheers
Matt

[McLEVIN]

Ive only seen mrp's kit and it looks quite extensive. And well worth the money What other ones are out there.

[Matt]

The problem i see with the MRP kits is they post up a range of parts which are worth close to 10k by the time you order them all but list the price at less than half of that.

Seamus did a set of custom rods not that long ago that used a stock 7a crank that was ground down to achieve the increased stroke. A machine shop in perth a couple of years back offered similar kits and I believe the owner of Parrys has also built one for his clubman.

[Course_Out]

I haven't built one myself, but have certainly considered it. Here is the pro/con list I came up with, based on building a naturally aspirated 9age:

Pro:
- Retains 4age "character" with greater torque. Most 9a kits I've seen are a touch over 1.9L at max bore
- Largely undetectable to the untrained eye (7a block is taller but would take a pretty sharp Corolla head to pick up on it)
- Allows retention of existing gearbox, engine mounts, etc. and any custom work to fit is well documented. The Spool kit also allows use of the 4age flywheel
- Probably easier to engineer if that is what you are into, as it uses all stock mounts
- It'd be pretty cool to say I had a 9age

Con:
- Pretty expensive (Spool kit is $2500 + machining and assembly, and clearly you are going to want to do the head, need extractors, etc. etc.). Basically its the cost of building a 4age + the cost of the stroker kit. You could do it on the cheap (stock head, cams, etc.) but that seems like a bit of a waste to me.
- The ceiling for usable, streetable horsepower is probably around 200hp, which is available from a 3sge beams. Yes the Beams requires more work to fit, but it allows a lot more room for future development and the swap is well documented these days
- If you are competing in any form of motorsport you will be bumped into Type 3 due to the block change (same would be true for stroking a 4age), a class in which motors such as the 3sge are allowed. If you are chasing outright power the absolute max you would get from a 9age (forgetting building an exotic, 10000rpm engine in an open wheeler or similar) is about the starting point for a stock or lightly breathed on 3sge.

So, in my OPINION:

I would probably do the 9age for a street car. Keeps the character of the ae86, looks like a 4age to 99% of people and would possibly be easier to engineer. I think a street 9age retaining the stock inlet manifold and running some 272ish cams would be really fantastic on the street and a huge amount of fun on the track. Would probably be around 170hp by my guess, but super flexible. I would like to run this in my car one day, although it puts me up a class for hill climbs, against some very serious machinery

If I was building an out and out race car (either a type 3 improved production or a Type 4 sports sedan) or was chasing outright HP, I think there are more cost effective options, particularly as you will likely need to change gearboxes and diffs at that level. By the time you built a 9age to this level you could probably just put in an F20C and have a much more reliable package.

Again, this is just my opinion based on what I use my car for. I'm interested to see what other guys think

[McLEVIN]

For me I was able to get a decent worked 7age motor 2nd hand so the mrp stroker kit is very appealing to me.

[McLEVIN]

And I think the mrp 9agte is in their car now so itll be interesting to see sime dyno figures

[Jimmee1990]

You can also use a 1ZZ-FE Corolla crank in the 4A/7A block, has an extra 6mm of stroke and the same bore spacing. It's also still a forged steel crank. For the money it would cost to build versus the power you would make it wouldn't really be worth it in my opinion for the MRP stuff unless your a purist and it has to be an A series Toyota...

[fantapants]

yeah for the effort involved in the capacity there are better ways to go about it. only reason to do it as far as i can really tell is if you are stuck with class rules, really love the traditional 4age look, or want to be different. any and all of these are worthwhile, but in all likelyhood a stock beams with quads and ecu will produce a butttonne more torque and hp... along with a better box.

[Konakid]

yeah for the effort involved in the capacity there are better ways to go about it. only reason to do it as far as i can really tell is if you are stuck with class rules, really love the traditional 4age look, or want to be different. any and all of these are worthwhile, but in all likelyhood a stock beams with quads and ecu will produce a butttonne more torque and hp... along with a better box.

Nail on head.

[Matt]

In FWD format, you would buy a 2zzge engine all day long over the 7a stroker. RWD you'd buy the Beams 3sge or even honda f20c.

Even if you are keeping the 4a / 7a series engine realistically the gains given by the 0.1L increase in displacement won't be earth shattering or mind boggling. I've built a half decent 7age 20v , and TBH it didn't rev anywhere near like I expected it to.

Yeah it pulled reasonably well, but in hindsight the 5k spent to get there was not worth it. At the time I could have bought 3 blacktop 20v engines and for the price i built the 7a one.

And before everyone else asks, YES the timing was set correctly with adjustable cam gears.

So my opinion is you may as well stick to a 4a engine, bump the compression a bit, put in some decent cams and port your head and a good exhaust and still have change from what it would cost for a 9age stroker kit.

In turbo applications, if you make a decent manifold, chose the right turbo you can achieve some pretty decent results from both 16v and 20v.

[Sam-Q]

I don't trust that spool kit, the counterweights look completely undersized. Also while it's only a 2mm increase in throw/ 4mm stroke 4age engines already have a pretty bad rod to stroke ratios, adding to that would only make it worse.

Something I don't hear much about is how about the harmonics fare from these, if the results of what someone talked about previously on here are to be trusted then making the rod/stroke ratio worse the harmonic issues become disproportionally worse. Seeing 4AGE engines aren't great in this regard to start off it's worry. Example of such is a shop in QLD that has a customer break multiple cranks before putting the stock main pulley back on to absorb some of the vibratons.

I also don't understand how the bottom end holds together with extra long throw cranks, these bottom ends only have a basic 2 bolt main cap design and they don't have any serious reinforcing either. Sure the machined reinforcing "girdles" might help but how much I wonder.

Anway seeing people have been giving me way to much false credit lately with things I better add I don't know any of the above for sure, I am not an engine builder and I don't have any meaningfull real world experience with built engines either.

[marvis]

^^^

I wouldn't bother. 7AGE/5AGE if you're wanting more stroke etc.

[Jimmee1990]

I don't trust that spool kit, the counterweights look completely undersized. Also while it's only a 2mm increase in throw/ 4mm stroke 4age engines already have a pretty bad rod to stroke ratios, adding to that would only make it worse.

Something I don't hear much about is how about the harmonics fare from these, if the results of what someone talked about previously on here are to be trusted then making the rod/stroke ratio worse the harmonic issues become disproportionally worse. Seeing 4AGE engines aren't great in this regard to start off it's worry. Example of such is a shop in QLD that has a customer break multiple cranks before putting the stock main pulley back on to absorb some of the vibratons.

I also don't understand how the bottom end holds together with extra long throw cranks, these bottom ends only have a basic 2 bolt main cap design and they don't have any serious reinforcing either. Sure the machined reinforcing "girdles" might help but how much I wonder.

Anway seeing people have been giving me way to much false credit lately with things I better add I don't know any of the above for sure, I am not an engine builder and I don't have any meaningfull real world experience with built engines either.

I agree with you on the crank design looking quite odd, was the shop in QLD that kept breaking them using the spool crank? Most cheaper aftermarket cranks are externally balanced, meaning you really need a specially made balancer to suit. Where as more expensive (read well made) cranks tend to be internally balanced and can use a much lighter alloy crank pulley with no negative effects.

If you really wanted to do a longer stroke engine, you would need to use the taller 7a block and get custom pistons with a super short comp height to help with the rod ratio. Those machined crank girdles do help also Sam, however a much better solution would be to machine a whole cradle with all the main caps and a girdle as one piece and cross bolt it through the side of the block or drill and tap the sump bolt threads larger and bolt through both the sump and cradle. Don't bother with those Tomei ladder cap things, they do almost nothing at all as it's not the basic cap strength that's the problem.

[Sam-Q]

The guy had all his failures on standard cranks. The most common breakage on 4age engines seems to be through the #1 big end. I do know what you mean by internally balances though, the true way to balance a crank is to bolt on specifically weighted dead weights to each big end and then turn it.

I have seen a picture of a main cap broken right in the middle. Apparently the standard caps are a bit soft and can do this so those support straps should help.

[pizzaeater]

I love MRP! 480kw 9agte with 1000NM of torque that still only manages a 10.8 1/4 mile time.

[Jimmee1990]

The standard cranks are externally balanced, so they do need either the standard damper or an aftermarket one which I'm guessing solved his problem?

I'm surprised the caps would be soft, Toyota blocks are usually pretty tough.

[Hen may possibly be a nut]

To answer your original question I say no, a 9AGE isn't worth it. I'd much prefer to choose a relatively stock motor that can make the power I'm after with simple or bolt-on mods. Good internal parts, machining and assembly are expensive and you cry if something breaks and you have to build a new one. A "new" 3S from the wreckers is relatively cheap and easy.

[Matt]

Just seen this posted up on facebook...

http://www.ae86drivingclub.com.au/dcimages/5/3/4/9/523796.jpg

1953nm of torque... even with the drive calcs etc.. lol really? and 340kw

I bet allot of performance shops would love this dyno.

[Sam-Q]

wouldn't that be multiplied torque? as multiplied by the gearing?

[Hen may possibly be a nut]

Never believe torque figures from a dyno plot. Usually the final drive and/or roller-tyre diameters are ignored.

[bazda]

Yep thats my dyno plot @20psi 98 pump gas.
Tuner didnt want to up the boost as he was concerned about knock and the low timing he had to use. He is very SAFE in another words.
I will be trying to dial out this knock with cam timing or different cams and will be using E85 on the next tune.
Once I can add the 10psi extra boost into this the numbers should be much more impressive. All this is done on a stock 20v head, the ports have not been touched.

You divide the torque figure by the final drive ratio. These figures are axle power/torque not engine.
They can set the torque graph to include the calculation but they just read it out as what the wheels read here in NZ.
So 1959/4.14 = 473Nm
Even then torque is not really a good measure on wheel dynos. Engine dyno is the only way to get a true torque reading. The dyno is used for reference, so you can see if you have made a gain or not.
My 7agte with similar kws did 1860Nm/449Nm on the same dyno with the same boost.

This power level can be achieved with a 4age base very easily as well. But the main difference is we are hitting full boost 1500-2000rpm earlier than the 1600 base. Which makes much more usable power.

On another note our 9agte engine is still making peak power @8000rpm, looks like it wants more revs. The drivability is fantastic and you can barely feel any lag.

Weather a 9age kit is worth it? thats really up to the customers to decide. The kit is not for everyone of course due to its cost.
You can easily stick with a 7a and still get good results, or move to a 2zz base for even more power.
There are other options of offset grinding the OEM 7a crank then getting custom rods and pistons to suit. The only issue is we have seen many 7a cranks break on the mains in the NZ racing scene so I never wanted to go down this route.

We built these kits as we had many customers asking for them. Mostly for race series guys where the cars have to retain the original block but can run up to 2L. These guys wanted the max amount of ccs they could get to squueze every little bit of power out of these engines. When your racing side by side, even 5-10hp can make the difference.
Currently we had around 5 guys from this one racing class in Aus buy our kits, they will all be running 20v heads. Looking forward to seeing them all run.
I only know of 1 that has theirs running which he made around the 250hp mark @9000rpm.

I did manage to get the car out to the drags over the weekend. Only got 3 runs then broke an OEM axle (teach me for not installing my billet one, thought it would last the day but I was wrong)
11.7@204 was the only semi clean run I got with a 2.12 60ft which is shocking. On my 3rd run I was off to a good start but hit boost cut which for forgot to raise during the tune. It was set 0.3psi above where the boost was set.

[Sam-Q]

It will be interesting to see how the local builds work out. I know that some of these guys are very serious about putting something mean together. If one of these is spinning at 9000 with a stroke that long then I am not giving the bottom end design enough credit in it's strength. Although I am still confused as to how it holds up.

One thing that hasn't been mentioned is the oiling holes on the 7A crank are drilled wrong for a performance application, there is an article on Club4ag on it. Not sure how much of a real world difference this makes with grooved bearings installed.

[bazda]

It will be interesting to see how the local builds work out. I know that some of these guys are very serious about putting something mean together. If one of these is spinning at 9000 with a stroke that long then I am not giving the bottom end design enough credit in it's strength. Although I am still confused as to how it holds up.

One thing that hasn't been mentioned is the oiling holes on the 7A crank are drilled wrong for a performance application, there is an article on Club4ag on it. Not sure how much of a real world difference this makes with grooved bearings installed.

Yea the oiling holes are not ideal for high rev applications. But they can be plugged up and re drilled the same as the 4age crank no problems.

I guess time will tell to see how these blocks hold up in 1900cc high rev applications Sam. But so far so good.
I know a company in Aus was doing a heap of them using the OEM crank into little sports cars and using Kelford cams. They were putting out in the 230-240hp range and only reving them to around 8-8500rpm.

[slydar]

It just depends how heavily invested you are in your 4a gear. some guys who actually race corollas have big $$ in their heads, drivelines, etc, so to them, sure it makes sense.

one point which others haven't touched on, 4a/7a/9a engines bolt into corollas.

3s engines don't. there are a lot of beams powered ae86's out there now but having been involved with a few conversions, it isn't the easiest fit. and its also heavier. again some 4A powered clubmans require major reengineering to fit larger engines, changing the engine in a registered ICV (lotus 7 replica's etc) would be a major headache.

a 9a isn't an obvious choice, but its good to have options.

3s is the better race motor but those who are restricted/bound to the A series motor for whatever reason it seems they can be made to work (though I agree with sam its hard to understand how)

[Jimmee1990]

The Australian company would have been Meridian I'm guessing? In a couple of those they did use the 1zz crank, not sure which one's made 240hp off the top of my head though.

[bazda]

As to why the 9age cranks work and dont explode the blocks.
The Crank effectively is the same size as the 7a crank. As the 9a uses 45mm journals vs 48mm of the 7a on the rod journals.
When you offset grind a 7a crank its still the same crank. You have actually taken weight out of the journals.
Yes the throw is longer of the conrod and piston which puts more forces onto the crank, but thats why we use lighter parts.
Therefore no material needs to be taken out of the blocks to let the setup spin, we actually gain a few mm more room over the 7a crank as on the rod journals they have big casting protrusions which we have to remove when using oil suirters in the 7a block.

This good enough for you Sam ? :)

[Rice86]

to keep it simple, if your not restricted by regulations, its a waste of money. better options to gain power with less money spent.

But if you had the money to do it, it'll will be freaking cool regardless LOL

[Matt]

7a revs nothing like a 4a. Building a 7age was not even worth it IMO.

Stick to a 4a and do work to that.

[bazda]

Going directly from 4a to 7a with no mods as in cams, it will rev less. Thats a fact. You prob wont gain a whole heap of actual power but you will gain more bottom end.
Turbo form the 7a seems to respond different, you can run a bigger turbo with bigger ex a/r's which then lets it rev and make power past 8k, and also spool up faster than the 4a.

The 7a is longer stroke, it will require bigger cams to fill the cylinders properly and able it to rev more in N/A form.
Modify the 7a right and it will be able to rev just fine to 9k. There are many race cars in Aus doing this.

Tec Arts in Japan use a 7age base in their AE86, I believe theirs seems to be the fastest car from the latest Hot Version race in Japan Fuji & Tsukuba.

But no doubt using later model engines will net you more power. 2zzge & 3sge beams.
I hope to one day have a play with one of those engines.

[Frak]

I went for a spin in a clubman with a modded BT, 132kw at the wheels G60 Quaife box with flat shit, was FRIGGEN FAST!!!

[Matt]

I'm in the mood to build some engines again...

Who knows more about using a 1zz crank in the 4a / 7a block?

[bazda]

I'm in the mood to build some engines again...

Who knows more about using a 1zz crank in the 4a / 7a block?

From what I understand:
1. The side walls of the block internals need machining so the crank can turn
2. Custom clutch/flywheel setup
3. Custom end housing that holds the crank seal
3. Custom crank pulley setup as the crank snout is shorter.
4. Custom rods and pistons

I looked into using these but these being only cast cranks with nearly no journal over Lap, I would def not chance putting through 9000rpm or 600hp. Crank flex is far more likely to happen.
Also with the crank snout being shorter the pulley would need to be much thinner in a area that 4ages are already prone to breaking pulley snouts.
Also the rod/stroke ratio would be just under the ideal 1.5:1 ratio when using our custom piston design.
Using any OEM rod/piston combo would net in a very bad ratio and massive rod angles etc as no OEM piston has a ch short enough.