4AGE camshafts (again)

[Alex170984]

Hi,

My name is Alex and I own a 1989 Mk1 Mr2 with the 4AGE engine.

I am about to start the rebuilding process of my red top 4AGE out of my MR2 – apologies for being on this website and asking questions as I am not an AE86 owner, but many owners with my model do not replace the camshafts and when they do it’s either HKS or Toda.

I have got limited technical knowledge - I am rebuilding the engine, but regarding camshafts please treat me as stupid, I will not be offended!!

I am looking for an alternative camshaft manufacturer, as paying £350 per cam is just not in my budget.

I want to get all the necessary information sought and parts purchased before I start taking it apart as I don’t want to start and then wait for my parts to be delivered.

But firstly, I saw other people’s power outputs and thought I’d post mine on here.

This is when I had a fully rebuilt ‘race prepped’ engine bought from Rogue Motorsport, which sadly 40k miles later blew its head through block corrosion – it was then replaced 3 months later (due to paranoia) with an AE92 4AGE engine.

Spec:-
81.5mm pistons
Standard HG
No head work
Exhaust & induction filter

It was dyno’d at 107.6 WHP which was around 130 at the flywheel. This engine just felt so crisp under acceleration but my current engine is sluggish as hell and seems to have a TVIS problem. But I have since started a new job and bought a diesel due to commuting 500 miles a week so rebuilding this engine is my project for the winter!

My project outline
Aftermarket Camshafts (Cat Cams / TED Components) 264° maximum
Toda Adjustable Cam Gears – if necessary
81.5mm pistons
Head & Block skim
Cometic Metal Head Gasket
Iridium Plugs (already purchased)
Fidanza Flywheel (already purchased)
4 to 1 Header (where can I find one delivered to UK?)

When I strip the block I will measure each journal for wear and obviously check all the bearings – if they are all in spec and not shown signs of wear they will not be replaced. I have a feeling the rings are worn as it was using oil up until it was put in the garage.

I am not familiar with the workings of camshafts however I have been around a 4AGE for 7 years now and spent enough time fixing it in the past to be able to rebuild it. I am unfamiliar with the technical knowledge of lift and the need for under bucket shims.

I have read on BillZilla’s website that removal of the TVIS helps with some cam arrangements?

A woman on the IMOC website specified Cat Cams as a good alternative to HKS and Toda and this thread was also posted on the forum, which I must say is very, very helpful!

If anyone has any HKS or TODA second hand camshafts they wish to sell please let me know.

TED Components were also mentioned.

Can anyone shed any light of what to and what not to buy when it comes to camshafts? I will buy adjustable pulleys if it is necessary to produce a decent idle but if they are not needed I will not.

Would it be possible to take the stock cam gears to a machinist and have them slot the holes for adjustability?

While I am here, has anyone got the factory measurements of the 4AGE cylinder head and engine block? I only ask as apparently my current engine has been rebuilt in the past (but no evidence) so I would like to know if it has been skimmed before and if it has how much I can further skim it for a completely flat surface for a metal head gasket.

My engine did overheat once on a long journey, it pressurised the system but I added more coolant before the needle got too high.

So that is my reason for skimming the head in case it is slightly out of square.

My aim is for 140-150 BHP but from reading this thread it could be as much as 160 which would be awesome.

I plan to use the car at weekends and for track days / car shows. I have already got the twin pot Celica front brakes with red stuff modified Scoobie pads, braided hoses and Koni suspension, as well as other modifications, so upgrading the engine was the next move, as I have the necessary stopping power and handling for the extra power.

If I didn’t have to spunk £800 having my wheel arches re-engineered I’d spend more money on well-known branded camshafts but I do not have that luxury as they are rotten.

Any feedback and advice would be greatly appreciated!

Best regards,

Alex

[fax0815]

Loads of text there

Main question:
Are you staying with the standard ECU?

I asume you are, so 264° and 8,5 lift are the limits for the stock ecu and the stock valvetrain.

My 4AGE got 140hp at the fly and I havent changed the cams, so with a set of cams you should easily see 150-160hp.

Don´t worry so much about brands, any cam will work(Newman, kelford, cat,dibilas,...), same with the camgears (which are recomended to dial the cams in properly) i.e. Fidanza camgears cost a lot less than JDM bummer stuff and works as good as.
Yes you can modify stock cam gears, but it´s not just a case of slotting them, get proper ones...

Refer to the engine manual avaliable from this page, for all the setting, measurements.

Get the head skimmed, doesn´t matter if its been done before, there is loads of meat on those heads.

Get an adjustable fpr to keep the AFR ratio ok.

If you´re staying stock ecu I´d personally keep the TVIS, or if yours is faulty, fix it.

[Alex170984]

Hiya,

Yes I am staying with the stock ECU and don't want to mess with the valve train too much.

The 260/252 cat cams seem like a good idea though they have a 8.5/9.0 lift. Is 9.0 not going to be feasible?

Also, what thickness head gasket should I get and is there anyone in the UK that retails a Cometic one?

Cheers

[Bean]

Hi, I think you are on the right way. The cat cams you list above (7105137
) are the perfect fit for what you desire. They should be fine with the standard lifters, just make sure the clearance is right (i.e. reshim it).
For the header look at Martelius Street or if you can find a Janspeed as your car is RHD, there's more choices for you, they are good value and suit your specs. Depending on how much was skimmed and what thickness headgasket you are going to use you might get away without camgears but as mentionied before it's advisable, so you can set it up nicely.

Regarding the thickness of the headgasket it's hard to say as we would need more info, which you will only have once the engine is apart.
As a guideline, considering you run the stock ECU I'd keep CR below 11:1 closer to 10.5:1 would be advisable as this changes the characteristic of the engine quite a bit and I'm not sure how much the stock ECU can handle. Stock deckheight is ~0.4mm if I remember correctly and you should have 10.3:1 pistons in the AE92 block. So you'll be looking at a headgasket in the regions of 0.8-1mm instead of the stock 1.2mm.

Last but not least once everything is back together you might want to have the AFR levels checked, if the are evenly at of spec you could change it with an adjustable FPR. Loads of cases unfortunately it's not so even.

PS: while you have the head of it pays of to have it slightly worked, at least debur the thing and maybe get rid of the hotspots next to the valves in the combustion chamber. The later is not easy to do and needs some experience and practice to get it right.

Hope this helps - loads more info around but as usual only time will tell.

Good luck

PPS: @fax: sent you a reply, hope I didn't offend you, as it certainly wasn't intended.

[Alex170984]

Hello,

Firstly, thank you so much for all this help so early on! Incredibly helpful and you guys are not losing me with technical talk LOL

As for the FPR I was looking at getting an Apexi SAFC to help me out with the fuel and air. I would get a Greddy Emanage but its pricey and the SAFC can be mounted in the cabin, doesn’t plug into a laptop but does the same job anyway.

I’ll try and work out what my compression will be to determine head gasket thickness, but you have given me a good idea, so hopefully the calcs will work out near your idea

I was considering dremelling out the casting marks on the head. I did have a quote done for engine work but the head price was starting at £75 and if I can de burr it myself I won’t do the hotspots.

I got a price from a company called Gosnays near Romford for £228 which included, head skim, block deck, head and block degrease, boring to 81.5mm and honing.

Got the same price from a company in Suffolk but Romford is only 10miles from where I work so it makes sense, unless anyone else can recommend a good machinists in the Essex, Herts, London Boroughs or Suffolk area?

Regards,

Alex

[Alex170984]

Bean Bandit Wrote:For the header look at Martelius Street or if you can find a Janspeed as your car is RHD, there's more choices for you, they are good value and suit your specs.

I have found many headers for the AE86 setup, but as my engine is in the middle and orientated 90 degrees than yours, finding one that fits is becoming an issue

[Bean]

Alex170984 Wrote:

Bean Bandit Wrote:For the header look at Martelius Street or if you can find a Janspeed as your car is RHD, there's more choices for you, they are good value and suit your specs.

I have found many headers for the AE86 setup, but as my engine is in the middle and orientated 90 degrees than yours, finding one that fits is becoming an issue

True forgot the part about MR2 while writing. Still check the Martelius page they might have one still. Else you might be able to adapt a header from a 20V blacktop (the 4-2 part) and do the rest yourself.
Don't know any machine shops in UK apart from AWT and he is good bit expensive and not easy to work with.

[totta Crolla]

Alex170984 Wrote:Hiya,

Yes I am staying with the stock ECU and don't want to mess with the valve train too much.

The 260/252 cat cams seem like a good idea though they have a 8.5/9.0 lift. Is 9.0 not going to be feasible?

Also, what thickness head gasket should I get and is there anyone in the UK that retails a Cometic one?

Cheers

Those cams are likely to need uprated springs and are probably right
on the limit of the standard shim arrangement.
The 4-age 16v responds really well to cam lift and sometimes I
think the lower lift long duration cams are a compromise to suit
the standard cam followers / shims

You will only likely get the best from uprated cams by using adjustable
cam pullies and time the cams for power not idling ability.

[Bean]

totta Crolla Wrote:Those cams are likely to need uprated springs and are probably right
on the limit of the standard shim arrangement.
The 4-age 16v responds really well to cam lift and sometimes I
think the lower lift long duration cams are a compromise to suit
the standard cam followers / shims

You will only likely get the best from uprated cams by using adjustable
cam pullies and time the cams for power not idling ability.

Valve springs and lifters will be on the edge with those lifters but will work if in goo condition/correctly shimmed.

And I agree lift is where it's at. Loads of people go for big duration and then wonder why they gain only little power. The wilder the cams the lower dynamic compression will be (which is fairly high in stock form ~8.4:1 from top of my head). My friend runs ~13mm in his race car (FA setup).

[Alex170984]

Hi all,

Thanks for the feedback so far!!

Had anyone used these cams from cat cams? Would be good to get to the bottom regarding the valve spring situation. Id rather not have to change them as then costs start piling up and i dont want to go all through that.