4AGE Bigport Cams. Difference between the 2 types?

[justin_es]

Good afternoon peoples.
I am after a set of bigport cams for my smallport ae93.

I was advised that I need to be carefull when buying bigport cams as there is 2 sizes. One size is same as stock smallport cams. 232 I think it is. Then there is the larger ones. 240 I think.

Now I have found a set of bigports claimed to be out of a series 2.

How do I know what cams are what size?
Or am I miss informed and all bigport cams are the same?

Also what are they worth? I've noticed a few people sold and are selling for $50 over a few forums does that sound about right.

I have a few sets available to buy but no one can tell me what size they are.

Cheers guys. Help will be greatly appreciated. Thanks.

[mattysshop]

your after Bigport cams from a 3 rib block... these are 99% sure to be 240deg 7.56mm lift. only different if someone has changed them..

the MR2 and some import AE92's use a 7 rib block, big port head. and i am not 100% sure if they use the 232/7.1mm lift or the 240/7.56mm versions.. i've always read conflicting things.. and all the bigport cams i've pulled have been from AE82 and AE86 bigports..

All GZE cams, bigport/smallport, AW11/AE92/AE101/Map sensored, AFM etc etc.. were ALL 232/7.1mm

not sure if that helps you at all..

[justin_es]

Hmm so if it comes from a bigport out of a corolla.
Its pretty much sure to be the 240 size then.

Is there something i can measure to make sure its right.
for eg how do i measure the 7.56mm lift to know its the right one?

i appreciate the reply mate.

[xero]

all bigports had the same cams regardless of the blocks underneath.

unless your getting the bigport cams for free or stupid cheap your better off look at something like 256 at 8mm lift which would give you a bit more power and RPMs with out sacrificing drivability at all.

[trdee]

your after Bigport cams from a 3 rib block... these are 99% sure to be 240deg 7.56mm lift. only different if someone has changed them..

the MR2 and some import AE92's use a 7 rib block, big port head. and i am not 100% sure if they use the 232/7.1mm lift or the 240/7.56mm versions.. i've always read conflicting things.. and all the bigport cams i've pulled have been from AE82 and AE86 bigports..

All GZE cams, bigport/smallport, AW11/AE92/AE101/Map sensored, AFM etc etc.. were ALL 232/7.1mm

not sure if that helps you at all..

this.

you can measure the lift with some verniers or whatever. measure the base circle dimension and then measure the total "height" of the cam lobe and subtract the base circle dimension to get the lift.

hockbro; bluetops had marginally bigger cams. at least to the bigport 4AGZE, which runs 232s for certain.. whether the redtop 4AGE had 240s or 232s or a mix is debateable depending on who you talk to.

[justin_es]

Unfortunately i dont have $300+ to spend on cams alone otherwise bigport cams would be the last thing id be after.
Im lifting the compression slightly with a 0.8mm head gasket and thought, alot of bigport cams are being sold for around the $50 mark so why not just upsize slightly while im there.

Otherwise the cams will be staying stock.

i know its a very tiny upgrade but even that is still better than no upgrade at all right?

i just didnt want to get cought buying cams the same size ive already got.
But according to you guys there all the same so should be sweet?

so if he has advertised them as out of a series 2. What would that mean they are from?
Blue top bigport?

[xero]

hockbro; bluetops had marginally bigger cams. at least to the bigport 4AGZE, which runs 232s for certain..

yah i know, all the N/A bigports were 246, the GZEs were the 232s. some confusion surrounds as to where the heads came from (GZE head are exactly the same as GE) which is why a few later bigport heads pop up with 232 cams, not the 246 that should be in there.

this is what i meant...

[justin_es]

so the bluetop bigports are 246?
and all others are 240?

hmm would still love to know which ones the ones im looking at are?
bigger the better :-)

[maj]

If you are looking at modifying the compression and cams, make sure you are only doing it in very small mods or else you'll find the engine management not coping very well and voiding any increase in power gains anyway.

[justin_es]

Thats the exact reason I'm only going bigport cams as that is very mild and a 0.8mm gasket rather than a 0.5mm gasket.

Other than extractors already fitted.
Exhaust and intake that's all I want when it comes to the motor that is.
This is just my little work and back toy so don't want to go silly with it haha.

So is $50 about right for a set of bigport cams?
That seems to be the going price on a lot of the for sale threads?

[Hiro]

Not only do 7-rib bigport cams have the same lift as smallport cams, they ARE the same cams. Lets put this to rest - part numbers tell the whole story

1984 MR2 - 3rib bigport (bluetop)
Intake cam: 13501-16010
Exhaust cam:13502-16010

1987 MR2 - 7rib bigport (red/blacktop)
Intake cam: 13501-16030
Exhaust cam: 13502-16020

1987 MR2 - 7rib bigport GZE
Intake cam: 13501-16030
Exhaust cam: 13502-16020

1991 AE92 Levin - 7rib smallport (redtop)
Intake cam: 13501-16030
Exhaust cam: 13502-16020

1991 AE92 Levin - 7rib smallport GZE
Intake cam: 13501-16030
Exhaust cam: 13502-16020

As you can see, 3-rib bigports have a different part number for both cams compared to all the other 7-rib models (both bigport and smallport). This correlates to the 3-rib bigport cams having more lift.

[justin_es]

So this gentlemen is advertising them as cams out of a series 2 bigport motor.
Im pretty sure its from a corolla not an MR2.

What does this suggest to you the cams SHOULD be?
i know you wont know for certain.

[andrew_mx83]

Hey matey dont forget you cant just slap a different set of cams in there and drive it, you need to set the clearances as well which may mean buying shims unless you have a stack of them lying around.
On the bright side you only have 16 of them to do

[Hiro]

To me, they sound like 7-rib bigport cams, which are exactly the same as 7-rib smallport cams (which you already have).

Depends on what the "series 2" is referring to. Could be referring to a Series 2 AE82, in which case they could be either 3-rib or 7-rib (3-rib was standard in Series 1/2 Twincams, but a lot of AE82s have had the 7-rib swapped in, and the Series 3 end-of-model runout supposedly had the 7-rib standard). If it is referring to a series 2 4AGE/bigport, then that sounds like 7-rib, in which case they would make no difference to the smallport cams you already have.

Since the seller doesn't seem to have much in the way of concrete information, I'd either pass them up or at least get the seller to accurately measure lift with verniers to determine exactly which ones they are.

[maj]

Or they don't happen to have them written on the ends? I should have a look when I get home to see if there's any indication of the cams out of my bigport GZE. I know they will be 232 but it would be cool if they SAID that.