9 replies to this topic

[Pie]

Right, as some of you may have seen. My project is a 998 iwht 100bhp with no forced induction.

I have been looking at heads and cams todays (well cam lol) initially so i know what i want, and how much its gonna set me back!

The engine in basica will be a 998block whichi will be pocketed, and have a 1275 head on it a fancy cam and a few other trick parts.

Heads im looking at here

These are the ones im looking at;

GT6/1
GT14
GT15
GT17
GT18!!!PRICE!!!

All the valves sizes are there, just insire on how much pocketing i should do!! As i wouldnt want to get too close to the edge of the housing!

Then i was looking at Cams!

649S race;
===================
Power band RPM: 3700-8500
Duration in /ex: 300-312
Valve Lift: 400"-420"
Timing: 50-70 81_51
Full lift: 100
Valve clearence cold: 014"-016"

Which would be best headwise? and would i be looking to reach the 100bhp mark with this cam? or would i be better looking at on of the Special Tuning cams??

Dont forget this is a 998 block which will be pocketed and then have a 1275 head on it.

Some help would be wonderful.

Cheers pie

[Pie]

BUMP

[Pie]

PLEASE SOMEONE HELP ME OUT!!!!

[lew]

use the 2000 pound plus and buy a med engine lol

Edited by lew, 05 March 2007 - 01:47 PM.

[The Matt]

As I said to you on MSN Pie, the problem is that you need to take gearing into account. If you are gonna go with a 3.1:1 FD ratio, you need a cam that has a bit of low end performance. All of the lairy cams are going to have power bands from like 3k rpm and up. If you're gonna build a high revving motor, with a cam duration of anything over 280 degrees, you're gonna want to run a low geared FD ration I reckon. But that's just my opinion/thoughts.

I'd say, (bearing in mind your SCCR gearkit) go for a 300ish degree cam and a 3.7:1 FD ratio. Build an engine that'll rev like mad and have some fun through the gears, without struggling to pull away.

It's best to talk to someone who knows about engines though! And I don't!

[taffy1967]

Like Bill Richards or Richard Longman perhaps?

[Pie]

Lew where did you dream up £2000 and MED engine? And why go MED whn you can go Bill Richards or swiftune??

[Pie]

Right so i have recently purchased a MSPH3 cam, and followers, and a Swiftune Vernier duplex timing kit.

Anyone got any comments on suggestions for a Head???

[The Matt]

Leaded MG Metro 12G940! Already got good sized valves in it. Or a 1300GT 11 stud one. Both are a good start point.

Either way, I'd look at getting a custom one from the likes of Bill Richards racing or Swiftune or MED, rather than a listed one. I got a quote off BRR for a custom one for £600-650ish.

What is your bottom end spec? I have been looking for decent 998 cranks, but don't know where to look. Did you find owt???

[Pie]

MED do specalist cranks for 998s, but i was also looking at Swiftune.
I am going for a 12g940 but not too sure if i should maybe look at Longman heads or not!?