1498 replies to this topic

[analogue_radio]

Right okay, I'll look into the duplex timing chain.

Cam & porting the head sounds far too expensive at the moment!

Cheers Andrew

[mini_mad69]

But we can talk about cams, just to put a bee in my bonnet and so I can understand it all a bit more, what would I benefit from? I guess that if I upgrade the cam, I'd need to upgrade other things to cope?

Adding a cam will add a little more performance, and then adding a different head will give you more again. Although you could slap in a new cam and always change the head later on, or you could always do it yourself, i've seen heads for 998s for sale at £5 at shows, thats going to be a very cheap way of tuning. It's good practice to change cam followers when doing the cam aswell.
Duplex is a good idea, as said it minimilises chain stretch. Fitting a duplex means that you will need to slightly modify the timing cover but I did this in around 5 minutes, you will also need to countersink the timing plate and fit drum brake screws to stop the chain from catching the bolts. Again this is 5 minutes work, it's just you need too know before hand otherwise it leads to alot of head scratching, like me.


Im not sure what cam to recomend as im not entirely sure what sort of driving you do. My car is a road racer/b road basher. SO I've fitted a lumpy, revvy cam too my car. Although this is annoying when town driving as there is no bottom end power. I did minimal tuning on my 998 engines so did not research into what suits them.




Ben

[AndrewJ530]

No bother mate ,

Porting the head you can do yourself for free as long as you have a decent drill to do it with that is. Dremel's cost about £80 if you don't have a drill. But the cam could cost you close to 200 squids for the kit.

I've seen 286's in 998's (JetBlick's project thread) but very lumpy and no bottom end like ben said. I'd probably say use a 266 or 276 if you want it a bit more lairy. I've also heard that the mg metro cam is similar profile to a 266 (don't know whether you can get them in a 998 - someone else who reads this will be able to confirm that for you bud) so if you wanted a second hand cam that might be a scrapyard jobby for you.

If you were serious about putting a cam in i'd do some research and talk to some engine builders. They'll be abel to tell you the profile you'll want but i'd say go for the 266 or swiftune sw5-07. Just my humble opinion lol

Cheers,

Andrew

Edited by AndrewJ530, 22 July 2009 - 05:50 PM.

[analogue_radio]

My ideal engine would be pokey & revvy around town & country lanes, not fussed about a high top end speed as I don't do a lot of motorway driving.. I've sat quite comfortably at 60-70 on dual carriageways and motorways in the past though, I just want something with a bit more of a bark!

Drum brake screws just screw right in? I've noticed those bolts whilst having a good look around everything, so I understand why it would catch.

In what way does the timing chain cover need modifying?

If I was to touch the head & cam I'd want to do both at once.. sounds like something I'll do in the future

[mini_mad69]

No bother mate ,

Porting the head you can do yourself for free as long as you have a decent drill to do it with that is.
Cheers,

Andrew

Yup thats what I was saying, and you can pick up a 998 head very cheaply.

I have heard the MG metro cam goes very well in a 998 aswell. The MG metro cam is also very similar to that of the 90's cooper cam. I had a cooper 1275 engine before the 1380 and that went quite well, lot's of mid range power.

I have the 286 in my 1380 and it's lumpy, in a 998 it would be silly, the larger the capacity the lumpier cam you can get away with.


Ben

Edited by mini_mad69, 22 July 2009 - 06:02 PM.

[1275 SPRITE]

You shouldn't have to fit drum brake screws, most good duplex sets come with special screws in the kit.
I think £200 for a cam is way over the top, MED sell cam KITS, their "phase 2" kit includes a piper cam of your choice (i'd go for a 276 personally), a new oil pump, new followers AND a vernier adjustable duplex timing set, which is everything that people have mentioned changing and all that lot is £175.
I dont agree that you wont notice the difference unless you port your head, it purely depends on what profile cam you choose.
An £80 dremmel is not needed to port a head, the heads I've ported have been done with flapwheels that can be bought from hardware stores for a few quid and come in different grades.
I ported a 998 head for Dan a while ago, and on a cheap head to experiment I opened it up too much and went through into a pushrod hole , so you have to have a good idea about what your doing.

Edited by 1275 SPRITE, 22 July 2009 - 06:13 PM.

[AndrewJ530]

You shouldn't have to fit drum brake screws, most good duplex sets come with special screws in the kit.
I think £200 for a cam is way over the top, MED sell cam KITS, their "phase 2" kit includes a piper cam of your choice (i'd go for a 276 personally), a new oil pump, new followers AND a vernier adjustable duplex timing set, which is everything that people have mentioned changing and all that lot is £175.
I dont agree that you wont notice the difference unless you port your head, it purely depends on what profile cam you choose.
An £80 dremmel is not needed to port a head, the heads I've ported have been done with flapwheels that can be bought from hardware stores for a few quid and come in different grades.
I ported a 998 head for Dan a while ago, and on a cheap head to experiment I opened it up too much and went through into a pushrod hole , so you have to have a good idea about what your doing.

Porting the head you can do yourself for free as long as you have a decent drill to do it with that is. Dremel's cost about £80 if you don't have a drill. But the cam could cost you close to 200 squids for the kit.

I never said the cam itself would cost £200, i said the kit would cost close to it. Minispares 266 cam kit's are around £190 which is close to £200.

How did you get inside the port with a flapwheel? Pretty tight last time i looked.

Edited by AndrewJ530, 22 July 2009 - 06:24 PM.

[1275 SPRITE]

It was tight on a 998 head because the ports are small to start with. You can get hold of quite small flapwheels that are a good size for 998's.
something like this http://cgi.ebay.co.u...-He...:1|294:50
with different size wheels

Edited by 1275 SPRITE, 22 July 2009 - 06:44 PM.

[mini_mad69]

You shouldn't have to fit drum brake screws, most good duplex sets come with special screws in the kit.

Not if you buy one new off ebay, but without the box.

You can buy them a shows aswell, thats just 2 gears and a chain.
I never said adding a cam on it's own wouldn't add power , I just said combined with a head, it would be even better



Ben

[1275 SPRITE]

I never said adding a cam on it's own wouldn't add power , I just said combined with a head, it would be even better

Agree, but a head could be done at a later date?

[Deathrow]

Would it not be a good idea to mention the costs of rolling roading the engine after these modifications are made?

Thats whats put me off doing any DIY modifications to my 998 head.

Looking good Luke! Get yourself some gunk if you've not already, it's shockingly good stuff.

[jaydee]

What about this kit?
http://www.swiftune....duplex-kit.aspx

Sw5 its what you need if want to retain the original power below 3.5k

[mini_mad69]

I never said adding a cam on it's own wouldn't add power , I just said combined with a head, it would be even better

Agree, but a head could be done at a later date?

yeah, ofcourse you could add a better head later on as funds allow.



Ben

[analogue_radio]

Guys I will (and sorry to disappoint) be keeping it fairly standard to how it is now, as I don't have the money, I'd rather spend my money on getting her on the road sooner

I will replace the followers, oil pump, vernier duplex timing chain & clutch though however.

Cheers for the input, it's been helpful!

[analogue_radio]

Okay so today was my last free day before going away, busy over the weekend as well.. wanted to tidy the garage up and organise a few bits, also remove as best I could the oil from the patio

Gearbox, clutch & other assorted bits laid out.



Some of the nuts and bolts cleaned up.



What does this bracket do? I've never seen it used.. I don't think.



Tidied.





How my GBs should sit.. bit higher though!