7age: how to?

[PBaines]

Thread resurrection:

How is everyone's 7A-GE builds coming along?

I myself have just picked up a 7A-FE bottom end and a 16v Big Port head for my build. It will be turbo'd and running a lot of the MRP gear. Hoping to get 240kw ish


Will be a build log with that all going into my KE20 later in the year

[bermy]

Thread resurrection:

How is everyone's 7A-GE builds coming along?

I myself have just picked up a 7A-FE bottom end and a 16v Big Port head for my build. It will be turbo'd and running a lot of the MRP gear. Hoping to get 240kw ish


Will be a build log with that all going into my KE20 later in the year

Stalled awaiting customs Carillo rods for my own long rod destroked 7A. Also going into a KE20 later this winter/spring.

[trdee]

waiting on another blacktop 20v head. as soon as it is in my hands the engine will be getting put together

[JustenGT8]

This is the worst 'how to' thread i've come across and the links to what may have been decent instructions are dead? Is there a definitive 7A build thread out there anywhere? something that covers the small stuff like gaskets, pump compatibility etc as well and the big components?

[Stolic]

This is the worst 'how to' thread i've come across and the links to what may have been decent instructions are dead? Is there a definitive 7A build thread out there anywhere? something that covers the small stuff like gaskets, pump compatibility etc as well and the big components?

Hey Justen, you're right there isnt too many good 7age threads about, but apart from a few key points they are much the same a building a 4age.
Blocks are essentially the same, with the 7a being taller by 18mm or so, so all the bits that bolt up to the 4a will usually fit the 7a no worries. The 7a block can even be machined to use the oil squirters from the 4agze/20v blocks.
As far as gaskets go, use the headgasket that matches your head, all other gaskets are just general 4a stuff. 4a water pumps work, as do oil pumps, just use black top pumps to match a black top head, otherwise 16v or silvertop can use the normal 4a pumps, or you can use the 7a pump in a pinch. If using a 20v head, the water pipe from the head to the water pump will need to be extended due to the taller block.
The front timing gear will need to be changed to a modified 4a one (recut keyway to get the teeth in line) and then use a 16v timing belt if using a 20v head.. or if going 16v a porsche 944 belt works. The better option would be to talk to Barry @mrpltd as he has timing belt kits available that include timing gear(modified), correct timing belt,and new belt tensioner.

As for the insides.. depends what you want from the motor. I have built a 7age based off a 16v head. Simply put 16v pistons on the stock 7a rods and crank and did a basic bottom end rebuild using 4a bearings (again, same as 7a) and ARP rod bolts. Worked well in a daily driven street car but there is room for improvement as it still had the rubbish rod/stroke ratio that the 7a was "blessed" with. If you want better performance this will have to be sorted by swapping rods and using some custom pistons to get longer rods in there. Again, Barry is the man to talk to here as he stocks 7a rods along with other goodies like the more uber 9a full stroker kits available and he's been building these things since before the internet (so it seams lol) so he'll give you more reliable info than the internet

Other than that, basic 4a engineering applies, but if I've missed something I'm sure more experienced voices will chip in

[trdee]

All as above, the only other point I will add is that if you use a 4A oil pump on the 7A block, you will need to port match the oil pump outlet as it doesn't like up with the gallery on the block 100% and also the top alternator tensioner bracket needs to be customised if using a 20v head due to the same height issue which requires the extended water outlet.

[JustenGT8]

Ok here's what I have got.

7A block and crank
Spool forged 132.5mm rods
CP forged 20v pistons
BT head with Kelfords cams and toda cam gears, VVTi deleted
SamQ water circuit stuff
BT oil pump.

I can get an offset keyway for the crank pulley but if I've bit adjustable cam gear I may not need it?

So, tips?

Edit: and rotrex SC so won't need to pull revs over 7500

[-GT-]

Nice ninja edit. Won't need to, but doesn't mean you won't...

[oldeskewltoy]

Ok here's what I have got.

7A block and crank
Spool forged 132.5mm rods
CP forged 20v pistons
BT head with Kelfords cams and toda cam gears, VVTi deleted
SamQ water circuit stuff
BT oil pump.

I can get an offset keyway for the crank pulley but if I've bit adjustable cam gear I may not need it?

So, tips?

Edit: and rotrex SC so won't need to pull revs over 7500

One issue with using standard 4A pistons.... the deck height is crap......... Deck height sizing(or "squish") is the gap between the pistons flat areas behind the valve reliefs, and the flat part of the head, when the piston is @ TDC. If you choose to not get custom pistons you need to machine the blocks surface so you end with a final deck(squish) measurement of .8mm to 1.0mm.

This is the secondary reason I've found 7A builds to be underwhelming.

As to rod to stroke ratio... the 7A and 4A are nearly identical... and there is a reason for it

[trdee]

Ok here's what I have got.

7A block and crank
Spool forged 132.5mm rods
CP forged 20v pistons
BT head with Kelfords cams and toda cam gears, VVTi deleted
SamQ water circuit stuff
BT oil pump.

I can get an offset keyway for the crank pulley but if I've bit adjustable cam gear I may not need it?

So, tips?

Edit: and rotrex SC so won't need to pull revs over 7500

throw money at bazda for a recut timing sprocket, extended water outlet, alternator bracket and a mechanical timing belt tensioner. it's easier to just get it all from him than fuck around with it yourself.. then go get yourself a BT water pump and tensioner pulley, a 16v timing belt, a BT engine seal kit, and you're pretty much done

[JustenGT8]

throw money at bazda for a recut timing sprocket, extended water outlet, alternator bracket and a mechanical timing belt tensioner. it's easier to just get it all from him than fuck around with it yourself.. then go get yourself a BT water pump and tensioner pulley, a 16v timing belt, a BT engine seal kit, and you're pretty much done

Ta mate, that's what wanted to hear Barry has plenty of my coin already so what's a few more $$$s not as much of my coin as he has yours though !

[roy8532]

I think if you can find a build guide on a engine that is very similar to the 4age it will help you out alot.

[Bazda]

Our rods are actually longer than OEM 7A rods so you dont loose the squish up in the chamber and you also dont need to skim 0.8mm off the block to bring pistons level.

There are many companies who make rods for the 7A but actually have no idea about the conversion at all. They just sell stuff basically.

[oliveoyl]

Ok here's what I have got.

7A block and crank
Spool forged 132.5mm rods
CP forged 20v pistons
BT head with Kelfords cams and toda cam gears, VVTi deleted
SamQ water circuit stuff
BT oil pump.

I can get an offset keyway for the crank pulley but if I've bit adjustable cam gear I may not need it?

So, tips?

Edit: and rotrex SC so won't need to pull revs over 7500

Updates mate? I think I might have to build one of these at some stage. Really cool option.

[JustenGT8]

Updates mate? I think I might have to build one of these at some stage. Really cool option.

Effort focussed on the Cressie for SM1000 but keen to take stroked and blown Clubbie to Toyota Nats so right into that come the new year.