Fitting a n/a cam

[Benjibrady]

Hi all,

Been offered a b18e cam and a reasonable price and I'm tempted to get it and fit before the new engine goes in question I have is, is it as simple as sliding it in and lining up the timing marks, or do I need to buy a vernier etc? If it is the latter then I'll leave it.

Thanks again

Ben

[Nottswoody]

I don't think you need a vernia bud.. I believe mine has n/a cam but Marky mark is your best man to ask.. Drop him a pm.

[Benjibrady]

Right spoke to mark and I just need to time it up using the standard timing marks, what he did say however is to check the cam followers as they may need to be shimmed. Does anyone now how I go about doing this pics would be great if anyone has one

Thanks again

[jamesy12345]

Hi, this has been discussed a fair bit on the Volvo 480 forum....I have a B18FT engine in my 480 and a spare B18E cam which I have never fitted as I wasn't sure about the timing.

The site below is a Dutch site and the guy posting, Robou, is pretty clued up on this stuff. I have a couple of his modified ECUs.

http://www.volvo480forum.com/index.php?topic=7352.0

Quote:

Een nokkenas van een NA motor hoort niet in een geblazen motor.

A camshaft of an NA engine does not belong in a blown engine.


De overlap zorgt ervoor dat ingeblazen mengsel in de uitlaat verdwijnt, bij andere toerentallen/minder druk gebeurt het omgekeerde omdat de turbo in het uitlaatsysteem zorgt voor een hogere tegendruk.


The overlap ensures that breathed mixture in the exhaust disappears at other speeds / less pressure, the reverse occurs because the turbo in the exhaust system ensures a higher back pressure.

Heel misschien is er ergens een toerental/boost combinatie die werkt.

Just maybe there is somewhere a speed / boost combination that works.

Wat kan helpen is de timing van de nokkenas iets later te zetten, hooguit 6°.

What can help is to set the timing of the camshaft slightly later at most 6 °.

Dat werkt positief op het inlaatgedeelte, maar negatief op het dito uitlaat.

This has a positive effect on the inlet section, but negative on the exhaust ditto.

Dat laatste is wat minder kritisch en het resultaat kan zijn wat meer vermogen bij hoge toeren, minder bij lage.



The latter is less critical and the result may be a bit more power at high rpm, less at low.

[Benjibrady]

That doesn't quite work bud, a lot of the guys on here have had a lot of success with a n/ a cam. I know scoff has done a lot of work with them

[jamesy12345]

That doesn't quite work bud, a lot of the guys on here have had a lot of success with a n/ a cam. I know scoff has done a lot of work with them

I don't doubt it, for me higher lift and longer duration must be useful somewhere. Just passing it on mate, no personal experience of it. I have a Volvo T5 that I am planning on putting some NA cams in but that is DOHC so can play more with the timing to get the overlap down.

Like I said I have a B18E cam ready to go in my 480 also. Reading between the lines on what Robou was saying - it does work with the correct timing but you need to sacrifice some torque at the bottom end for top end gains. Which is fair enough! From what I have read about it if you do put a higher lift cam in but exhaust back pressure is high that is where potential power is lost.

[Benjibrady]

Oh right I see where your coming from, thanks for the info mate,

[Haz]

A wilder cam opens the valves earlier, for longer and further into the head thus giving more air flow. The problem with a ma cam is the amount of overlap, when both valves are open with air going straight through the engine without the explosion to spool the turbo. So the turbo will spool a little later, but more airflow will allow more boost as everything revs faster.
Ideally you want more lift, longer duration but less overlap, a turbo cam.
Basically a na is just a cheap improvement over original.

[jamesy12345]

A wilder cam opens the valves earlier, for longer and further into the head thus giving more air flow. The problem with a ma cam is the amount of overlap, when both valves are open with air going straight through the engine without the explosion to spool the turbo. So the turbo will spool a little later, but more airflow will allow more boost as everything revs faster.
Ideally you want more lift, longer duration but less overlap, a turbo cam.
Basically a na is just a cheap improvement over original.

good explanation, thanks Haz . On the T5 I'm going to put the N/A cams in at standard timing then try changing the timing a little at a time to see if the quarter mile times come down. I'm hoping to get hold of an R5 at the end of the year, it has a higher lift cam installed, not sure from what so no idea about overlap etc.