4age big port cams in a small port head/

[pete05]

Can this be done? has anyone tried it as a cheap cam upgrade. If it can be done would they make much difference?

Edit: found they fit but do they make any difference?

thanks
Pete

[oldcorollas]

small difference in duration and maybe lift?
if you have them for free.. why not? (and have shims/don7t need them)

then again, some cheap 256 or 264 will work better

[pete05]

I like how you say cheap 256 or 264! i guess i will have to keep an eye out for some.

cheers

[Hiro]

Yes it can be done, as been discussed quite regularly on Twincam.org.

Here are a few threads regarding it:

How to tell the difference between bigport and smallport cams
Toyota's cross model swapable parts
Bigport cams into smallport

Hope that sheds some light

[takai]

Yeah, works perfectly. I only did mine as i was pulling the head apart for a bit of work on the GZE. Didnt really notice any difference.

[Grippy]

I did mine, no real difference, runs a littel smoother and thats about it.

[fandio]

i found there to be a bit extra in the midrange, but i also only replaced them while the head was off. but if your keen to rip it apart any extra is a bonus

[pete05]

yeah head has to come off for a BHG thats why im asking. did a compression test and got 225 in 3 cylinders and 200 in the one where the gasket is blown

[blacktop]

Why not just get your existing cams Reground? cost more than bigport cams but you will get alot more bang for your buck with a regrind

[Grippy]

Why not just get your existing cams Reground? cost more than bigport cams but you will get alot more bang for your buck with a regrind

Where and how much does this cost??/

[Munki]

the one local to me said $20-25 a lobe and another $60 to set shims if i had the head with me. Your mileage may vary

i just hit the yellow pages and looked up camshaft grinders.

[blacktop]

Where and how much does this cost??/

Clive Cams Ferntree Gully Victoria, $80 a cam last time i went there about a year ago.

[Cuts]

just as a matter of interest. How is regrinding cams done?
i see two possible ways:
1: weld the cam lobe, prob around the point of higest lift, then cyl grind. back so it all intersects smooth.

2: the other way i can think of is to grind off say the back half (ie when it doesnt touch the bucket or rocker or however its actuated) then put in thicker shims or adjust the rocker closer to the cam. effectivly giving the same ramp rates and everything but with more lift.

[trdee]

afaik most people do number 2.

[takai]

Method 2 is called reducing the base circle. Its the normal method im led to believe.
That said, 4A billets dont cost THAT much. IMHO if you are going to do it, do it properly.