4AGE Bigport Cams. Difference between the 2 types?

[justin_es]

I think your right Hiro.
Might be better off passing unless he can give me the lift size.
Oh well keep looking for now.

Andrew_mx85 its all good.
I wasn't even going to attemp these myself anyway haha.
That's also why budget only allows cheap bigports as I gotta get them fitted. Hopefully they can just do gasket while there there.

Cheers guys.

[trdee]

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.

series 2 bigport = red top 4AGE = smaller cams. doesnt matter if its out of a corolla or an MR2 or whatever else.

[trdee]

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.

I have no idea why I haven't done that before, lol. At least it confirms what I always believed, that the 240deg cams were only ever available in the 3 rib/bluetop engine

Ill update the 4AG info thread i have on twincam with this

[mr2gze]

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...

Thats the wrong way to look at it (confusion surrounds as to where the heads came from..) and what you are saying is completley incorrect. Firstly all N/A bigports were NOT 246deg nor were they ALL 240deg, the part numbers in Hiro's post above confirm this 100%.

The later 7rib bigport 4AGE (red/blacktop) has the 232deg cams (13501-16030, 13502-16020).

[justin_es]

ok found how to measure it anyways.
Just need the right tool to do it now :-)

Smallport cam diagram.


So clearly i just need to find the ones with 7.56 lift.

Cheers guys.

[dnegative]

Fuck, so I went from 232's to 264's

[trdee]

ok found how to measure it anyways.
Just need the right tool to do it now :-)

Smallport cam diagram.


So clearly i just need to find the ones with 7.56 lift.

Cheers guys.

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.

did you miss this post?

[knightrous]

If the cams are in a motor, a simple way to measure the lift is to remove a rocker cover and setup a magnetic dial gauge on the cams and rotate it a turn or two. Bit of a guide here on how to do it: http://www.biggles.net/cams.html

[justin_es]

did you miss this post?

haha no sorry i didnt. but yes i forgot it was there.
The thing is the way everyone is explaining it to me doesnt seem necessary.
Just measure the height of the lobe.
Thats how the pic says it. Dont need to minus base height etc etc?

Correct me if im wrong.
Maybe its just more accurate that way?

Knightrous
Measuring in the car would be a handy thing to know for future refernce.
Cheers mate.

I need to start buying these sorts of tools. Although not used often. Very handy to have.

[trdee]

yes but you cant measure the height of the lobe directly using something like verniers, you need to measure the height of the base circle and subtract that value from the height of the lobe + base circle

you'll get what i mean when you go and try to measure them....

[justin_es]

I understand. Just in that illustration it looks like you can measure it without doing that.
Like you said ill find out when I see it for myself :-)

Cheers mate.

[andrew_mx83]

You cant...

[JDM hachi]

You cant...

.....well not with any degree of accuracy....

matty.

[trdee]

considering the difference in lift between the 240 and 232deg cams is only 0.46mm you definitely do need accuracy

[justin_es]

Lol. When you put it like that. Got me thinking. That's so minimal. What's the point.
But in saying that changing the head gasket is no longer a want its a have to. So while its all open if I can pick them up cheap then why not hey? Haha.