4AGE camshafts (again)

[fax0815]

Not much to add to the info above,
because you´re on the edge of the capability of your stock valvetrain, uprated springs are advised, they´re only around 120quid and worth it, but get the verniers first! Remember your springs have been fitted to an engine for around 20 years, on the 4 AGEs I´ve build they didnt even meet the factory specs.
A ~260° duration with about >8mm lift properly shimmed and dialed in,will keep the engine pulling right to the limiter, rather then creeping out at 6500rpm.

If you ask me, don´t waste money on Apexi SAFC/ Greddy Emanage! (Use the money for good bearings, ARP conrod bolts and decent pistons, cause that will make you a very good base engine, for whatever your plans are in the future) Run the standard ecu for now, tweak the fuel pressure to compensate while you´ve got the air fuel ratio checked out (Every dyno will check/ adjust this for you for 50quid). SAVE the money towards a freedom ECU, like emerald, Omex (that can be mapped by everyone!!!), it will give you a lot more advantages in the future, if you want to go ITB´s, or wilder cams, of course its about a 1k investment, so no ideal for starters, but definatly something you should consider...

Regarding CR ratio and standard ECU, I can guarantee there are no problems, my very first 4AGE, had the head skimmed to the absolute maximum (it wasnt me who did it), litterally one more skim whould have taken material of the valve seats!!! Ran fine When I rebuild it I´ve changed the pistons for the US spec 9,4:1 (iirc?) ratio pistons and remachined the pockets, was lazy back than so didnt bother to calculate static compression, but it must still be fairly high, has done me 20000km in driftdays and still loves it on the stock ecu.
I´ve to admit, it´s allways been on 98 or 100octan fuel.

[oldeskewltoy]

Stock springs will bind @ about 8+mm of valve lift (NOT cam lift). If you don't believe me you can take a stock spring to a machine shop... following the FSM set the spring to standard install height, and then check coil bind once you've added 8+mm of compression. This is something you can't do in the engine because you can't get access to the coils to check for bind when installed.

As far as I know the cam with the most lift for stock springs is Web camshafts/Kamikaze camshafts 294 grind. This cam has a cam lift of 8.18mm. Both of these camshafts are similar to "256" type camshafts


If your intention is to run a cam that exceeds the 8.18mm lift of the above stated one, you really should invest in a set of Toda valve springs. The Toda springs are good for lifts exceeding 10mm, while remaining affordable.

[totta Crolla]

"SAVE the money towards a freedom ECU, like emerald, Omex"

just to add that the Freedom ecu is a brand in its own right and is
as far as I'm aware not a generic name for programmable ecu's.

The content of fax's post is spot on imho

HKS valve springs will cope with at least 9.5mm lift

[Bean]

I can't remember exactly which spring were used but apparently there is a OEM VW spring that fits nicely and does the same as HKS etc... unfortunately I can't find the details anymore.

[Alex170984]

Hi,

I'm sorry but I have no interest in another ECU that is not in my plan. As I have been advised that the cams I am interested in do not need another ECU.

I've wanted to give the 4AGE more power and this is what I am doing. Spending money out on an ECU when I have to get my wheel arches rebuilt is not something I want to do. Sorry.

I've found some HKS uprated springs for £120 on Fensport - can I use these with cat cams?

Cheers

[Alex170984]

fax0815 Wrote:Not much to add to the info above,
because you´re on the edge of the capability of your stock valvetrain, uprated springs are advised, they´re only around 120quid and worth it, but get the verniers first! Remember your springs have been fitted to an engine for around 20 years, on the 4 AGEs I´ve build they didnt even meet the factory specs.
A ~260° duration with about >8mm lift properly shimmed and dialed in,will keep the engine pulling right to the limiter, rather then creeping out at 6500rpm.

If you ask me, don´t waste money on Apexi SAFC/ Greddy Emanage! (Use the money for good bearings, ARP conrod bolts and decent pistons, cause that will make you a very good base engine, for whatever your plans are in the future) Run the standard ecu for now, tweak the fuel pressure to compensate while you´ve got the air fuel ratio checked out (Every dyno will check/ adjust this for you for 50quid). SAVE the money towards a freedom ECU, like emerald, Omex (that can be mapped by everyone!!!), it will give you a lot more advantages in the future, if you want to go ITB´s, or wilder cams, of course its about a 1k investment, so no ideal for starters, but definatly something you should consider...

Regarding CR ratio and standard ECU, I can guarantee there are no problems, my very first 4AGE, had the head skimmed to the absolute maximum (it wasnt me who did it), litterally one more skim whould have taken material of the valve seats!!! Ran fine When I rebuild it I´ve changed the pistons for the US spec 9,4:1 (iirc?) ratio pistons and remachined the pockets, was lazy back than so didnt bother to calculate static compression, but it must still be fairly high, has done me 20000km in driftdays and still loves it on the stock ecu.
I´ve to admit, it´s allways been on 98 or 100octan fuel.

I have recently checked my valve clearances and they were all within tolerance....

[Bean]

Alex170984 Wrote:I've found some HKS uprated springs for £120 on Fensport - can I use these with cat cams?

Cheers

yes you can.

[Bean]

Alex170984 Wrote:I have recently checked my valve clearances and they were all within tolerance....

He's talking about the squarness of the springs - with time they go out of shape.

[Alex170984]

Ah Okay – understand now.

I’ll see if Fensport can get me those valve springs.

The existing ones will be removed anyway as it’s having a degrease, skim if it’s bent with valves then lapped in again.

I was going to get a hold of some Supertech valve guides instead of crappy ones you get pattern part gasket sets.

[Bean]

Alex170984 Wrote:Ah Okay – understand now.

I’ll see if Fensport can get me those valve springs.

The existing ones will be removed anyway as it’s having a degrease, skim if it’s bent with valves then lapped in again.

I was going to get a hold of some Supertech valve guides instead of crappy ones you get pattern part gasket sets.

once the head is apart you can check the play of the valves, according to the manual it might not be necessary to change the guides.