If I fit an uprated cam......

Hello,
Quick question to the MK1 gurus. If I fit a fruitier cam to my MK1 GTI, will I have to do heaps of other adjustments, e.g. valve timing, rolling road etc? Any advice gratefully received. 

Thanks

First thing I would ask is Hydraulic or Mechanical head, and ignition is it points/condenser/vacuum advance or Electronic.

Briano1234 said

First thing I would ask is Hydraulic or Mechanical head, and ignition is it points/condenser/vacuum advance or Electronic.

Mechanical I'm pretty sure

DaBullCam said

Briano1234 said

First thing I would ask is Hydraulic or Mechanical head, and ignition is it points/condenser/vacuum advance or Electronic.

Mechanical I'm pretty sure

 electronic I think as it's an 83 Mk1 GTI 

To maximise the full potential from a cam then yes. However fitting an uprated cam into a stock motor can give some gains but often the gains are rivaled by the losses in other areas. I slapped a 285 piper in my stock motor for a bit and yea it had more power at the very top but was horrible around tick over. K jet doesn't like lots of valve overlap low down.
Maybe a 270 or 262 cam would be a better option.

Yomp said

To maximise the full potential from a cam then yes. However fitting an uprated cam into a stock motor can give some gains but often the gains are rivaled by the losses in other areas. I slapped a 285 piper in my stock motor for a bit and yea it had more power at the very top but was horrible around tick over. K jet doesn't like lots of valve overlap low down.
Maybe a 270 or 262 cam would be a better option.

Thanks, that's really good to know and backs up what I have already read. It seems that lots of people run an uprated cam for a while and then revert back to stock for the reasons mentioned. I've now picked up a fully rebuilt head that's been ported and gas flowed which will do me just fine - if nothing else the engine should make the power it's supposed to. 

For what it's worth, a cam swap will require a set up to get the best out of the timing and fuelling. If you have had your head and valves done properly then an uprated cam is almost a must. The important thing in choosing an uprated cam, is how you drive. As already stated a piper 285 would give more HP, but it was at the top end. One of the things I loved about the DX is it's ability to be a nice civil plodder oubouter as well as tear up a bit of tarmac. The likes of a 285 piper would not have suited 95% of my driving. Kent and Piper used to do mild and fast road cams. Schrick was well known for good cams and had a split profile (268/272 IIRC) that was highly rated for a daily driver.
In short, yes get a decent tune up and with the head mod, it's a great combo. A mild road cam will still give you more power throughout the rev range with the head. Wilder the cam, lumpier the idle/low revs.

wooders said

For what it's worth, a cam swap will require a set up to get the best out of the timing and fuelling. If you have had your head and valves done properly then an uprated cam is almost a must. The important thing in choosing an uprated cam, is how you drive. As already stated a piper 285 would give more HP, but it was at the top end. One of the things I loved about the DX is it's ability to be a nice civil plodder oubouter as well as tear up a bit of tarmac. The likes of a 285 piper would not have suited 95% of my driving. Kent and Piper used to do mild and fast road cams. Schrick was well known for good cams and had a split profile (268/272 IIRC) that was highly rated for a daily driver.
In short, yes get a decent tune up and with the head mod, it's a great combo. A mild road cam will still give you more power throughout the rev range with the head. Wilder the cam, lumpier the idle/low revs.

This is really helpful, thanks a million!

If you stick with a stock cam make sure it has a "G" stamped on it. There are a couple of alternative stock gti cams out there. Classic parts De were selling new "Stock" GTI cams but they are "H" grind cams and are a bit softer than the G grind. Probably for the American market or something. There's less overlap on a H grind.