7afe's.. tell me everything you know.

[johnny]

also couldnt hurt to have the rods shot peened...

mine always are, as well as a linish, ... I just could be bothered listing every thing done, let alone the cost over the past years that had gone into it.
3S, very nice diagrams, any chance of letting me know where they came from? Looks very similar to the "max ellery" or "Haynes" ones I have, but are no where as good as that since mine stops at the AE92 series......No 7AFE in them! That is exactly what the differences are on the internals, perfect! Just need to add some 4AGE piston etc to help.. Also I would like to mention that the Early 4AFE's have a different head and EFI manifold and the late model 4AGE block (20V's) have similar looking sump bolt patterns to a 7A block, but still uses a steel sump and that stiffener... this I have investigated yet.

[Dimitri]

so its 20mm little end. but doesnt say if its floating or press fit. oh well enough people have done it before. ill just buy one and do it.

"crank shaft pin" is interesting. 48mm. HUGE. plenty to play with there, easy to see how the clubbie guys get those huge capacitys (1900cc plus).

[johnny]

so its 20mm little end. but doesnt say if its floating or press fit. oh well enough people have done it before. ill just buy one and do it.

"crank shaft pin" is interesting. 48mm. HUGE. plenty to play with there, easy to see how the clubbie guys get those huge capacitys (1900cc plus).

All the FE I' ve come across are pressed

[Dimitri]

cool thanks for that. so what do you do? press fit the pin and just let it floating in the piston?

or bore out and fit a bush and run it full floating like in the 4age?

[3sgte]

cool thanks for that. so what do you do? press fit the pin and just let it floating in the piston?

or bore out and fit a bush and run it full floating like in the 4age?

That is the question that stopped me from doing the head swap. At the time, I was looking for a no brainer displacement bump, I even had a set of stock later gen 20 mm floating pin type 4AG pistons off a 91 AE92. Decided I would wait for the money to have some custom pistons made (bought an ST165 instead).

Given the lack of oil squirters, I wasn't sure if there would be adequate pin lubrication in the bottom of the piston.

If one were to bore the small end out for a bush, would there be enough meat left there to run at 7000 RPM?

If people are claiming "weak rods", or have rods that failed, is this just because they are running a floating pin in a rod designed for a press fit (or a press fit pin in a 'floating type' piston)? In other words, a pin that doesn't have the lubrication or clearance it was designed for?
Pin sizing is typically very precise, I would expect that as a sticky point for doing a mix and match job with the pistons/rods as I had originally anticipated.

This isn't to point fingers, this is just a 'devils advocate' kind of thinking. I mean, if the failures are all "big end" failures, then I guess it hardly matters.

I would have only felt comfortable winding the motor out with aftermarket pistons (due to pin concerns).
Also, the big end bolts are plastic region type bolts. This means that the bolts are actually stretched as the 90degree final step is performed. Running at 7000-8000 RPM, I would want a new set of bolts each time.

If anyone has experienced big end failures, I am all ears. Did the bolt break, or the threads pull out of the rod?

[johnny]

That is the question that stopped me from doing the head swap. At the time, I was looking for a no brainer displacement bump, I even had a set of stock later gen 20 mm floating pin type 4AG pistons off a 91 AE92. Decided I would wait for the money to have some custom pistons made (bought an ST165 instead).

Given the lack of oil squirters, I wasn't sure if there would be adequate pin lubrication in the bottom of the piston.

If one were to bore the small end out for a bush, would there be enough meat left there to run at 7000 RPM?

If people are claiming "weak rods", or have rods that failed, is this just because they are running a floating pin in a rod designed for a press fit (or a press fit pin in a 'floating type' piston)? In other words, a pin that doesn't have the lubrication or clearance it was designed for?
Pin sizing is typically very precise, I would expect that as a sticky point for doing a mix and match job with the pistons/rods as I had originally anticipated.

This isn't to point fingers, this is just a 'devils advocate' kind of thinking. I mean, if the failures are all "big end" failures, then I guess it hardly matters.

I would have only felt comfortable winding the motor out with aftermarket pistons (due to pin concerns).
Also, the big end bolts are plastic region type bolts. This means that the bolts are actually stretched as the 90degree final step is performed. Running at 7000-8000 RPM, I would want a new set of bolts each time.

If anyone has experienced big end failures, I am all ears. Did the bolt break, or the threads pull out of the rod?

Thread pulled out on all the one's I've had, and I have run a season and a half with standard rods, bored out with the floating pins, and yes precision is a must... but I have also run the inference setup too. We went to A/M cause I didn't feel there was a need to spend $$$ every year or spend every second season on the sideline half way through+ even more $$$$... it was Better spent doing it right first time (should say second ) but then again the engine was spending all day, every day on the higher side of 7,300-7,500 and the fatal nail was a missed gear seeing it soar to around 9K , not once but on a third oops on the same corner.... I will admit I would of liked some oil squirters there and they can always be install afterwards with a bit of thought and most likely trail and error.

[Dimitri]

thanks for the great infor johnny.

[johnny]

thanks for the great infor johnny.

good to be of help

[psychofox]

I'm in the process of seriously considering a 7A-GE Build at the moment, and wanted to ask some people in the "know" some finer details.

I have a working 4AGE 20V in the car (an AE86) at the moment, I'm looking for some more low down urge. It's going to be in a daily driver and used for some Hillclimbs, Track days, etc. I've already got engine management (LT10s) and I'm not likely to flog the crap out of it for extended periods. I'd say a max rev limit of 7500rpm is realistic.

I'm going to use a Silvertop AE101 20V head, My reasons for using this head are:
- I have a 20V Silvertop head (Actually an entire spares engine)
- I have a set of AE101 Quads (so I don't have to cut/shut a Smallport inlet one or get a AE86 bigport one - or buy a 16V-Quads adaptor)
- Stock AE101 Cams are longer duration/Lift than Smallport or bigport cams. (250/7.9mm vs 232/7.1mm or 240/7.56mm)
- VVT might make low end a bit better (but am unsure if this still can be used)

Some questions:

What timing belt to use? Timing Belt - I read Camira - can someone confirm this? What part number (ie Gates Txxx) - 4AG16V is 113T vs 4AG20V is 111T - porsche 944 is 117T so i assume this mystery belt is around 115T???

What oil pump? Should I use the 7AF or a 4AG20V one?

Which pistons? I was thinking of using Toyota AE111 11:1 +0.5mm Oversize or should I not bother with OEM and just go to forged i.e. ARIAS/Wiseco/TODA...

Rods - should I convert the Little End to floating? or just leave it as press fit and float the piston? What about rod bolts? For Light duty (is less than 7000rpm) should I just get new bolts from Toyota? Or am I dreaming and Aftermarket rods are definietly required?

Cam Timing Gears. I assume I need to use vernier cam gears, as the timing changes by about 3-5deg. I really only know of TODA making gears for the Inlet cam on a 20V head - but this disables the VVT. Does anyone make a Vernier VVT Cam Gear? Would it be a waste of time? Or can I just leave the VVT one there and use a vernier exhaust gear (as the VVT moves the cam by 15deg anyway).

Any help would be greatly appreciated...

[allmtr]

Hen, you should know I would find this thread. Ring CB Performance, have around $7K ready, and they'll produce a 20V 1900cc engine that rev's to 'only' 8500rpm and makes 170-180hp all day.

Is that C+B performance in Seven Hills?

[Dimitri]

for the 20v its a camira timing belt.

i was back at that workshop today(ke55 7a20 IPRA car)

he runs his gudgeon pins pressed into the rod. heads the rod then presses in the pin in the same fashion you would any press fit wrist pin.

i have asked him before.. i am pretty certain he uses the 20v oil pump. if it bolts up i would say use it.

ae111 will give you more CR. in fact quite a bit more. as the silver top head has a smaller combustion chamber. you would want to be carefuel. the ST runs larger squish areas.. there may be clearance issues running 111 pistons with a 101 head. if it works though you will get monster compression.

greg runs his motor to 9000rpm on unmodified rods. from what i can gather from this thread and research in the past, 7500rpm seems to be a realistic and reliable red line.

the timing thing isnt a massive issue. you can run stock gears wityh either the 16v or 20v.

[johnny]

Is that C+B performance in Seven Hills?

yep.. Bearing Rd Seven Hills, Straight across the road from the Hymix Concrete Plant

ae111 will give you more CR. in fact quite a bit more. as the silver top head has a smaller combustion chamber. you would want to be carefuel. the ST runs larger squish areas.. there may be clearance issues running 111 pistons with a 101 head. if it works though you will get monster compression.

This will be harder than what is seems since the AE111 (Black top) pistons have a really high crown than match the low squish area head. These actually come very close to hitting the squish areas in the S/T head, best tried and true, Just deck the S/T head as much as you can go!

should I not bother with OEM and just go to forged i.e. ARIAS/Wiseco/TODA...

Just go A/Market by the time you actually get +0.5mm O/S geniune there won't be much difference in price nor it it worth waiting if there not avaliable. I current use Wiseco ones in the 20V, but run JE in the 7AFE. Stick to any of the good brands and you should be fine.

[terryo]

we have built lots of race engines by just floating the pin in a steel rod. you have to drill an oil drip hole at the top.
the 7A factory rods failed regularly and there was a reasonable warranty problem with them from memory. various rods will fit, but mostly if they have studs (rather then bolts), the head of the stud hits the block at the bottom of the bore,and lots of block machining is needed (did one friday).
fitting squirters is a real problem on the 7A block due to the internal casting shape (lack of metal really). I have modified the rods to be like 20V black-top/honda, with a squirter groove up the side.
the late 4AG 16V, 7AF and 20V oil pumps are internally identical, its just the shape for the plastic cover that varies. The black top 20V is different cause it has provision for bolting on a tensioner

[3sgte]

the 7A factory rods failed regularly and there was a reasonable warranty problem with them from memory.

In the engines built for race applications presumably?

Just asking to clarify, because they weren't an issue in normal use and I don't want anyone to take your comments out of context.

[Sam_Q]

old thread dig-up time,

I know its been asked before but is it ok to float the pistons but press the rod?