Outer Limits 4x4 Board

Just thinking about seeing about getting my cam reground while im at it. Its the old nissan diesel sd33T.

any one got a rough idea on price? i have no idea but figuring its way too dear. If i did id prob just get the exhaust side done

IMO reground cams are a waste of time and money... Sure you will get the profile you are after but you lose quite a bit of lift...
Just ring a cam making/grinding specialist and get a new one..
EG: Ivan Tighe or COME or CROW.

what he said ... never done one in a 4wd ... done it once on a 351 4v clevo ...

want33s wrote:IMO reground cams are a waste of time and money... Sure you will get the profile you are after but you lose quite a bit of lift...
Just ring a cam making/grinding specialist and get a new one..
EG: Ivan Tighe or COME or CROW.

Interesting... i have a mate who is getting his 3litre (i think) deisel hilux cam reground by tighe, last week i think, engine going back in this week. Will let you know his opinion...

Lol you dont loose lift you gain it, by removing metal from the base circle then adjusting, machining or shimming the rocker gear (motor dependant) you now physically have more lift. The reason you dont make as much power as a new cam is on a regrind you can't change lobe spacing and therefore are limited, prices are very cheap 6cyl cam is about $110.

NutterGQ wrote:Lol you dont loose lift you gain it, by removing metal from the base circle then adjusting, machining or shimming the rocker gear (motor dependant) you now physically have more lift. The reason you dont make as much power as a new cam is on a regrind you can't change lobe spacing and therefore are limited, prices are very cheap 6cyl cam is about $110.

The only way to gain lift on a regrind is to grind the base circle only.. What is the good of that? The whole idea of a regrind is to change the profile which can only be done by grinding the entire lobe, thus reducing its size and overall lift.

Yep best to go with a new cam either in the same profile or just a little bigger to get a few more ponnies out of it (that would be my choice)

You can change the profile with a regrind. and you can gain lift as mentioned by machining the base circle down. The only limitations are that you are slightly limited by how radical the grind can be, but you can still get a bloody lumpy regrind. The other issue is it is possible, although it doesn't happen too often these days anymore, to get a dodgy weld on the lobes. What the companies do is fill in some of the lobe profile with weld, the regrind the whole lot down, allowing larger changes to the profile. Its possible that these welds, if not done right, can collapse a bit and cause issues to lifters, rockers, etc...

Its a personal opinion, regrinds are cheaper but valvetrain needs shimming to suit reground base circle or longer pushrods if this is the case, or a new cam is more expensive, but valvetrain should be fine if you're not going crazy amounts of lift.

If your only looking at a mild up size you can in get the desired results easily enough including increase in lift, on some motors you can grind some pretty reasonable sticks, what you cant do is get big increases in duration and you cant change ramp rate, saying outright they "CANT" increase lift is crap as that's mostly what you can gain becuase the base circle has the most meat to remove.

With that said by increasing the lift a bit on a turbo motor you can gain good improvements, and by not opening up duration to much you also dont push the effective rev range any higher, maybe if you dont understand these things you should avoid giving advice as if its fact.

With that said over the years I have installed regrinds for people when they have requested them on everything from 1.2 litre corollas to RB30s to 6lt V8's, some have gained well others have not.....Installing a cam with .600+ lift and 240/245 duration in a motor that flows 100/120 through the heads isn't going to work, a lot of bad results are from people going to big either becuase on paper it sounds good or they want a really choppy idle.

With that said on my own cars Ive never used a regrind as you can benefit from a new cam especially on older motors as Cam tech has improved somewhat.

well said nutter!
who does the new billets for diesels=upgrade profiles?
or is a machined s/h stick an easier option?
ive had regrinds before since when do they weld shit!

I never heard of anyone welding and machining them before, seems like failure waiting to happen, most guys that regrind cam also custom grind from fresh billet but expect to pay good money, I don't do much diesel stuff so I don't know who has them off the shelf....google is your friend though.

Welding cam lobes is as old as the hills. The cam face is built up with spray weld ( I call it powdered shim). This is why it has a tendency to fail, if the surface is not heated or cleaned properly the powdered shim will not bond well and after time with vibration will fall away.

ive heard of it being done to antique stuff!
usually last resort!

i used cam tech in Sydney last time i got one made and a new custom grind 6 cyl cam was $250

On an SD33, what's the aim of this exercise?

It's a high compression IDI engine, so your valves are probably already limited by how close they get to the pistons. Changing valve action isn't going to make it go noticably better unless your current cam is worn out.

If you want more air, up the boost.

KiwiBacon wrote:On an SD33, what's the aim of this exercise?

It's a high compression IDI engine, so your valves are probably already limited by how close they get to the pistons. Changing valve action isn't going to make it go noticably better unless your current cam is worn out.

If you want more air, up the boost.

was thinking along the lines of longer duration for the exhaust side only. May help with heat issues and a tad more ponies. I thought id ask about it in general and see whats available before i do abit of research.

want33s wrote:IMO reground cams are a waste of time and money... Sure you will get the profile you are after but you lose quite a bit of lift...
Just ring a cam making/grinding specialist and get a new one..
EG: Ivan Tighe or COME or CROW.

You don't loose lift, a cam grinder removes material from the base circle more than the nose hence giving greater lift within reason. It may require some adjustment to the mechanism that controll tappet clearance whether that be easy like old adjustables or machining the valve train mounting components such as is the case with VL's and alike.

Joel

i got a custom cam ground up for my old cruiser ute with the 3f petrol motor in it was nice a lumpy and seemed to hold gears in the sand that bit more better and was heaps better on eco and even better on gas

pongo wrote:

KiwiBacon wrote:On an SD33, what's the aim of this exercise?

It's a high compression IDI engine, so your valves are probably already limited by how close they get to the pistons. Changing valve action isn't going to make it go noticably better unless your current cam is worn out.

If you want more air, up the boost.

was thinking along the lines of longer duration for the exhaust side only. May help with heat issues and a tad more ponies. I thought id ask about it in general and see whats available before i do abit of research.

I wouldn't think so.
You'll be limited by piston clearance and valve overlap (turbo diesels have next to no overlap).
Under acceleration you'll have double the boost pressure in your exhaust manifold. Extra duration could keep more exhaust in the cylinder.

ive only ever used one new cam, all my 4 others have been regrinds with no troubles, all rangin in small to big lift. ive only been told that there can wear a little faster.

one motor is 4 years old and still ok though.

price have ranged from $100 to $150

dan.