Tips on making it better with a larger bore. If you are concerned about the thinning cylinder wall when going to an 83mm bore keep it to a max of 82mm. Simple. Sacrifice a few cc for reliability. If you MUST go 83mm and you're worried about the cylinder wall thickness then have the block sleeved. A set of chromoly sleeves might even allow a safe bore of 83.5mm. Darton cast Iron sleeves have a good, dense material with no voids, 83mm with no worries. All depends on how deep your pockets are. If you're building a race engine that should only last a season it shouldn't too much of a concern.

just realized OP already locked into this build it appears?
So he'll have to find out the limit of the bores himself or wait for that very rare, equal build/same use feedback

No such thing as "the point of owning an ae86" ....or "what a 4age was meant to be". = Nothing more than anyones' opinion
Slow, weak & dated = Fact. Hence why the vast majority of them are modified in a gazillion ways. A blank canvas

1/4 mile is a universally accepted yardstick. Why almost all vehicle reviews include em + 0-60mph
Has absolutely nothing to do with being a 'drag racer' ...meaningless to say "a car is fast" (loud, expensive, light, etc.)
Most have no access to 'twisty mountain roads'. Sounds like the dumbest place to 'hone one's driving skills'
Safe and controlled environment ? Hmmmm.... mkay

yabaiani wrote:Well said…my biggest concern is how to make the engine “safer” given the bore is 83mm so have heard that thinning the block can make it more prone to cracking. Any tips on making it better?

Since I have already pissed off the 7AGE advocates, I might as well piss off a few more people by
giving some more opinions that won't please everyone

1. I would never recommend that anyone bore a 4AGE to 83mm. I would suggest no more than
82mm if you want to stay safe and have the chance for one more 0.5mm overbore if anything
goes wrong. Since your specs say you are at the first overbore of 81.5mm I would stay right there.
The extra gained by going to 82mm is barely measurable.

2. Your specs also say that you are using "red top" OEM pistons which I guess are the smallport
high-comp pistons at 10.3:1. I ran an unopened 60,000 mile smallport engine with factory AE86
cast iron manifold, AE101 ITB's on a homemade manifold, some second hand 272 cams and a
self-tuned aftermarket ECU. Made 130hp @ 7200rpm. With a custom header, 0.85 MLS head gasket
and a dyno tune I'm pretty sure it would have got close to 150 @ the wheels.

You already have 140hp @7700rpm, so I would suggest that you forget the stroker kit for the
time being, and consider a decent set of high comp pistons. Something like this...


Wossner 1.6L 81mm 11.8:1 Pistons Toyota MR2 16V 1988-1992

3. The cams you have installed are relatively mild street cams. To really wake the engine up you
need as much lift as you can get and a bit more duration. Something like this...


Kelford Cams 193-B Toyota 4A-GE 16V Cam 284/278 Degrees advertised duration. 9.20mm/8.50mm lift.

These cams will work with OEM shim on bucket lifters, and don't require any grinding of the block.
In the video I linked above these cams made 171hp at the wheels. With your setup, 11.8:1 pistons,
the right squish clearance I would expect that you could probably make a bit more with a good
tune (cam timing, ignition timing and fuel).

Downside is that your car is not going to run like stock at the bottom end. You will need to up the
idle speed a bit to get it to idle decently, but it will sound nice while idling All of the above will
be fully reversible if you change your mind at a later date, and will cost a lot less than a stroker.

Cheers... jondee86

Pissed off jondee? no. I'm disappointed that there are still peeps out there that refuse to accept our eccentric, eclectic "brotherhood". Just 'cause you drive a Lambo doesn't mean you're too good for the guy in an MR2. Slammed, stanced, donk, aero, bosozoku, drag, drift, trailer queen, all should be appreciated for what they are. It's all part of the game, love it or leave it.

As for your suggesting not going over 82mm, for longevity it's best. For a street engine definitely. For a race engine, where every little ounce of torque matters..... It's why I mentioned sleeving the block earlier. If money is no issue.

Cams? If you take into account a stroked engine will tend to tame bigger cams, a set of 280 cams should idle like a set of 270 cams on a stock stroke 4AGE. Running a set of 265/8.6 (I believe that is close) cams in my 7AGE would idle acceptably under 1000rpm and pass our emissions testing. Same cams in a stock stroke 4AGE wouldn't make it. Although those 284/278 cams would still need a bit more RPM to idle in any case. Definitely will have a nice lope.

Sorry about that little rant.

sirdeuce wrote:Pissed off jondee? no. I'm disappointed that there are still peeps out there that refuse to accept our eccentric, eclectic "brotherhood". Just 'cause you drive a Lambo doesn't mean you're too good for the guy in an MR2. Slammed, stanced, donk, aero, bosozoku, drag, drift, trailer queen, all should be appreciated for what they are. It's all part of the game, love it or leave it.

As for your suggesting not going over 82mm, for longevity it's best. For a street engine definitely. For a race engine, where every little ounce of torque matters..... It's why I mentioned sleeving the block earlier. If money is no issue.

Cams? If you take into account a stroked engine will tend to tame bigger cams, a set of 280 cams should idle like a set of 270 cams on a stock stroke 4AGE. Running a set of 265/8.6 (I believe that is close) cams in my 7AGE would idle acceptably under 1000rpm and pass our emissions testing. Same cams in a stock stroke 4AGE wouldn't make it. Although those 284/278 cams would still need a bit more RPM to idle in any case. Definitely will have a nice lope.

See for me…I will be upgrading to Kelford 193D cams and then I will be doing the 83mm build with the BC kit. I will probably only drive the car here and there 1x a week or so. So I do care about longevity so I am wondering if getting the sleeves will help strengthen things up to have the best of everything…(and assume $ isn’t an issue).

http://www.raceeng.com/p-47161-darton-d ... rekit.aspx

sirdeuce wrote:As for your suggesting not going over 82mm, for longevity it's best. For a street engine definitely. For a race engine, where every little ounce of torque matters..... It's why I mentioned sleeving the block earlier. If money is no issue.

As the OP has now made it clear that he is set on using the BC stroker kit, there are a few points
that should be considered...

1. The BC kit can be delivered with pistons in any choice of bore size and compression ratio.
2. An 83mm bore size only leaves 4.5mm between bores for gasket sealing.
3. The 4AGE has been bored to 83mm many times and bore splitting is rare on N/A engines.
4. If in doubt, cylinder wall thickness can be checked using sonic testing
5. Fitting sleeves is a precision job and should only be trusted to a shop with a proven record of
building high performance engines.

I would strongly recommend that the engine builder be involved in the decision making process in
order that he can advise on bore size, compression and cam specs to get the best possible result.
For a car that is not intended for hard core track use, it may be that an 82 or 82.5 bore without
sleeving will be a safe and durable option.

Some people might say that because of the cost involved, building a stroker means that it will be
a race engine. However, if the OP wants to have a 16V sleeper, with 200hp available when the mood
strikes... hell yeah... do it

Cheers... jondee86

Yeah, sleeper, huhhuhuhuu.

yabaiani wrote:

sirdeuce wrote:Pissed off jondee? no. I'm disappointed that there are still peeps out there that refuse to accept our eccentric, eclectic "brotherhood". Just 'cause you drive a Lambo doesn't mean you're too good for the guy in an MR2. Slammed, stanced, donk, aero, bosozoku, drag, drift, trailer queen, all should be appreciated for what they are. It's all part of the game, love it or leave it.

As for your suggesting not going over 82mm, for longevity it's best. For a street engine definitely. For a race engine, where every little ounce of torque matters..... It's why I mentioned sleeving the block earlier. If money is no issue.

Cams? If you take into account a stroked engine will tend to tame bigger cams, a set of 280 cams should idle like a set of 270 cams on a stock stroke 4AGE. Running a set of 265/8.6 (I believe that is close) cams in my 7AGE would idle acceptably under 1000rpm and pass our emissions testing. Same cams in a stock stroke 4AGE wouldn't make it. Although those 284/278 cams would still need a bit more RPM to idle in any case. Definitely will have a nice lope.

See for me…I will be upgrading to Kelford 193D cams and then I will be doing the 83mm build with the BC kit. I will probably only drive the car here and there 1x a week or so. So I do care about longevity so I am wondering if getting the sleeves will help strengthen things up to have the best of everything…(and assume $ isn’t an issue).

http://www.raceeng.com/p-47161-darton-d ... rekit.aspx

rats those sleeves have gone up in price "Price: $555.75"
I am also planning another 83mm bore build
the reason is I have a set of HKS 83mm bore 4ag pistons but NA
I just bought a MRP crank girdle
if I remember right the cometic head gasket i bought years ago was 83mm

I also been on the look-out for an oil squirter block

I am glad people are still talking about and building 4ag/7ag

a dream would be a 9AG with 20V head lol

later

sirdeuce wrote:Yeah, sleeper, huhhuhuhuu.

No need to be a dick...

Cheers... jondee86

Davegt27 wrote:

yabaiani wrote:

sirdeuce wrote:Pissed off jondee? no. I'm disappointed that there are still peeps out there that refuse to accept our eccentric, eclectic "brotherhood". Just 'cause you drive a Lambo doesn't mean you're too good for the guy in an MR2. Slammed, stanced, donk, aero, bosozoku, drag, drift, trailer queen, all should be appreciated for what they are. It's all part of the game, love it or leave it.

As for your suggesting not going over 82mm, for longevity it's best. For a street engine definitely. For a race engine, where every little ounce of torque matters..... It's why I mentioned sleeving the block earlier. If money is no issue.

Cams? If you take into account a stroked engine will tend to tame bigger cams, a set of 280 cams should idle like a set of 270 cams on a stock stroke 4AGE. Running a set of 265/8.6 (I believe that is close) cams in my 7AGE would idle acceptably under 1000rpm and pass our emissions testing. Same cams in a stock stroke 4AGE wouldn't make it. Although those 284/278 cams would still need a bit more RPM to idle in any case. Definitely will have a nice lope.

See for me…I will be upgrading to Kelford 193D cams and then I will be doing the 83mm build with the BC kit. I will probably only drive the car here and there 1x a week or so. So I do care about longevity so I am wondering if getting the sleeves will help strengthen things up to have the best of everything…(and assume $ isn’t an issue).

http://www.raceeng.com/p-47161-darton-d ... rekit.aspx

rats those sleeves have gone up in price "Price: $555.75"
I am also planning another 83mm bore build
the reason is I have a set of HKS 83mm bore 4ag pistons but NA
I just bought a MRP crank girdle
if I remember right the cometic head gasket i bought years ago was 83mm

I also been on the look-out for an oil squirter block

I am glad people are still talking about and building 4ag/7ag

a dream would be a 9AG with 20V head lol

later

Yeah...I also bought the MRP crank girdle. I wonder after all of the build, what the max RPM would be for this car. But my main concern still is the overall strength of the block, and if I should block fill it, buy sleeves, or for my once a week daily cruising around town if everything will be fine.

jondee86 wrote:

sirdeuce wrote:Yeah, sleeper, huhhuhuhuu.

No need to be a dick...

Cheers... jondee86

That wasn't being a dick, check out "Bevis and Butthead".

I would suggest a crank girdle for any engine spinning to ridiculous RPM. Most would stop at ladder caps to strengthen the main caps, but the girdle will cut out a lot of the flex in the main bolsters at high power and/or RPM. In a stroked engine the crank gets pushed sideways more than with the stock stroke so a girdle is a good idea, regardless of balance level.

sirdeuce wrote:I would suggest a crank girdle for any engine spinning to ridiculous RPM. Most would stop at ladder caps to strengthen the main caps, but the girdle will cut out a lot of the flex in the main bolsters at high power and/or RPM. In a stroked engine the crank gets pushed sideways more than with the stock stroke so a girdle is a good idea, regardless of balance level.

I have both the main caps and the billet crank girdle so hopefully those two things will help!

Mannon's girdle incorporates ladder caps into the girdle. Nice piece! Expensive too.

sirdeuce wrote:Mannon's girdle incorporates ladder caps into the girdle. Nice piece! Expensive too.

What’s the best head gasket for this setup? I’m assuming cometic or something, probably at least a 1.0mm right? 0.8mm may be too high compression with the pistons being 12.5:1

I've only had TRD and Cometic in my engines. Good luck with them so far. Your compression is your choice, whatever you plan and tune for. My 7AGE is 10.5 to 1 so I can get by with whatever fuel is available. Most tell me it's low, but it's what I want. Runs good, has good power, gets good mileage and most important, passes our emissions test. 12.5 to 1? You can do it with the right prep and tuning, but 1 gas station with **** gas will give your engine fits.

yabaiani wrote:

sirdeuce wrote:Mannon's girdle incorporates ladder caps into the girdle. Nice piece! Expensive too.

What’s the best head gasket for this setup? I’m assuming cometic or something, probably at least a 1.0mm right? 0.8mm may be too high compression with the pistons being 12.5:1

Get deck measurements for all 4 pistons... once you know the deck, then you can look at head gaskets.

The more squish gap you have - the high the chance for detonation. Id rather machine your pistons then open up the squish beyond 1mm(.040")

Bit of reading for you 5AGE guys...





Cheers... jondee86

Looking at the kits available for the 4AGE and I see the MRP 1.8l 4AGE striker kit kicks 3% longer rods in the mix. That's about 3 1/2 mm longer. Would be a better choice than the BC kit as they use stock length rods. That's 125.6mm as opposed to the 122mm stock. 1.51-1 RS ratio as opposed to 1.47-1 with the stroker. Stock is 1.58-1. And since it's ME, the 7A has a 132.5mm long rod with an 85.5 stroke giving it a RS ratio of 1.55-1.

Through Battle garage the MRP kit is about $450 more than the BC kit, $3400 as oppsed to $2969 (right now, sale price.)

I think I read a thread somewhere that mentioned the 5AGE kit needed some clearancing of the block. Take that into consideration when dropping the block off at the shop. I think it was a thread from OST.

be interesing to see what one of these 'built' motors final cost, and the power output
Considering: machine shop + head work + big valve + ITB? + standalone, etc. Sound$$$$ like

What do you consider as "built"?

I did a "budget" build 7AGE that put a likely 145-150 hp and similar torque that was a blast to drive and only cost about $2k to build (about a decade ago). Last I heard, about 2 years ago, it was still running good. As far as "built" goes it was pretty well built.
I've had several 5AGE kits pass through my hands and never installed them. Some reason I never got around to it.

jondee86 wrote:Bit of reading for you 5AGE guys...




Cheers... jondee86

shame the HKS pistons aren't using typical HKS numbering.... I acquired an interesting kit recently... It looks to be 130JRA-10023C - its a floating 18mm pin piston kit - domes look to be slightly more then a smallport piston




personally I'm not a fan of peaked domed pistons... they really hurt flame propagation. Beginning with a 10.3:1 piston, with very little work (just a head gasket, and a .5mm overbore) and your static with that piston and a .032" squish jumps to 10.93:1. Plenty for most. And if you need more, that can be arraigned.

Traum and I have developed a new high comp piston option. A bit lighter, and MUCH stronger. Customizable too(from 9.7:1 to 11:1 - calculated with stock gasket)



Full size image -https://gallery.ostportworks.com/albums/userpics/10005/OST_Traum_high_comp_copy_versus_OEM_high_comp_6_panel_large.jpg

What do you consider as "built"?

as in the 'extra topings" as mentioned

machine shop + head work + big valve + ITB? + standalone, etc.

If you're gonna plunk 3 gran down on a 'stroker kit'.... I'd think you'd be going the whole nine, to match

"Budget build" sounds like.... 'slap' a stock head on a 7A bottom end, sync timing, stock head, oe intake, oe ecu

pics of my HKS pistons a friend got them off Yahoo Japan





only 2 rings

"Budget build" sounds like.... 'slap' a stock head on a 7A bottom end, sync timing, stock head, oe intake, oe ecu

"Budget" doesn't mean sloppy. You can build a satisfying engine on a budget. My desciption is nowhere near what you spouted off here. Don't knock it. My current 7AGE has close to 7k in the build, overkill really. For what I wanted a "budget" build would have been good enough.
As for "slapping a stock head on a 7A bottom just to see what happens?? Been there, and it was a blast! Back when it was just a concept that's the way it was done. Maybe you should try it.

Yeah, only two rings, and the compression ring is a 1.5mm. Second ring would add friction and they were looking to get every last bit out of the engine. Might just be me, but I wouldn't consider that for a daily driver. Not that the HKS 5AGE was designed for the street. At least the BC and MRP kits carry three grooves. 1.5, 1.5, and a 2.5.

If you were to go for a single compression ring cut the groove for a 2mm ring and shoot for a Total Seal ringset.

no 'spouting' anything. Gazillion 7A threads give you a good idea of what a "budget" build consists of
Just curious about what these 'costly' stroker builds run and the performance
...an no, I won't be "trying" any normally aspirated small displacement build.
Low performance/dollar value, way too weak and noisy for this boost-junkie
Now a stock 1UZ.... that's a different story

Only boosted vehicle I have is an '07 Mazdaspeed3. Getting old and slow, like to put around more than anything else. Latest aquisition is a Mini. NA and it's way slow.

sirdeuce wrote:Yeah, only two rings, and the compression ring is a 1.5mm. Second ring would add friction and they were looking to get every last bit out of the engine. Might just be me, but I wouldn't consider that for a daily driver. Not that the HKS 5AGE was designed for the street. At least the BC and MRP kits carry three grooves. 1.5, 1.5, and a 2.5.

If you were to go for a single compression ring cut the groove for a 2mm ring and shoot for a Total Seal ringset.

I have no experience with 2 ring groves, its just Duax machine e-mails me and says hey there are these trick parts on yahoo Japan do you want them?

I most often said yes since we only go around once in life

they are not for a street car anyways