Bigport head differences?

[JDM-086]

Just trying to work out why this bigport 4age head is different
I get the feeling one is a GZE head.
If so what differences are there? this is for a future NA build so i want to make sure I use the right head.

http://www.ae86drivingclub.com.au/dcimages/4/7/2/399871.jpg
http://www.ae86drivingclub.com.au/dcimages/4/7/2/399873.jpg



also whats up with those grooves??
http://www.ae86drivingclub.com.au/dcimages/4/7/2/399875.jpg

[Sam-Q]

those lumps are oil channels, got any more pics?

[JDM-086]

nah but i can take more. any specific areas? i just took these as at a glance they were the only notable differences

[timbo]

Top head is from an AE86 ONLY, it has no mount for FWD between the cams. Second has the mounts so it could be from anything, MR2 or Corolla. If it's bigport all you can do is guess what it's off.

[JDM-086]

ok so the head with the 2 holes between the cams simply means it's a FWD/MR 4age.
I'll have to speak to the previous owner.
Apart from the cams are there any other differences? how do i ID the cams?

[maxhag]

I have heads lying around that are like what you have aswell....

[timbo]

Cam's you would have to measure, unless you pull them out of a stock motor!

[JDM-086]

this might sound stupid... which parts do i measure exactly?

[timbo]

The lobes, tear drop bits. Google for the different lifts between big and small port.

[lolwat]

bigport is slightly more agressive, throw them in a smartport head

[JDM-086]

ok so the lobe is about 3.5 cm i have no idea how that translates....

[Hen may possibly be a nut]

ok so the lobe is about 3.5 cm i have no idea how that translates....

You need to measure the lift, and accurately. You're trying to see the difference between 7.1 and 7.56mm lift (numbers are from memory so likely wrong, but the difference is in that realm).