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GQ Dual Cab. TD42Ti with fruit.
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So after trying everything to get my 6758 to spool up properly under 2k I pulled it off last week and installed a 16g 6cm to test if the turbo was just too big.

What do you know the 16g spools up identical to the efr :unsure:

So this leaves me with either the pump or the cam, I was actually making a few calls this week about sourcing a silvertop cam but if the above is correct then that will save me a LOT of headaches.

As for 16g vs efr the 16g has better torque in the lower rpms obviously but the funny thing is it seems to take more to get going o_O hard to explain
My old turbo was a Garret 2860RS, generally regarded as one of the quickest turbos to get going low in the rev range, albeit with modest performance. And I reckon the EFR is about the same in terms of when it starts to spool up. After that no comparison.
 

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It has now been confirmed that the camshafts between the two engines are the same lift and duration, but are not interchangeable. The difference is in the timing. So those of us with T spec engines can change the timing of the cam to Silvertop spec by moving 1 tooth on the cam gear. @OldMav can confirm this, but I think it is about 5 degrees.
Bugger, i had my engine out and timing cover of a few months ago, anything involving the timing cover is a crap job to do in the car
 

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GQ Dual Cab. TD42Ti with fruit.
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Yes it is unfortunately. This only a recent development, so we did not know when you did your motor. It was being discussed, but all we knew was what the Silvertop engine did, not how. Quite a while ago, an owner fitted an EFR to a GU and got it all set up and dyno'd at about the usual power and torque figures. The motor carked it, and the owner fitted a Silvertop in its place. Normally it is difficult to compare one engine to another as every vehicle has a different airbox, intercooler, manifold, plumbing etc etc. But in this case all that stuff was taken off the GU engine and bolted on the Silvertop with not even a setting change to anything, and it made 900nm straight away. I am told it opened a few eyes up at the time! LOL

Once Oldmav was convinced it was the cam, I gave him my Silvertop cam to compare to a disassembled T spec engine he had access to. But that was only recently.
 

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Yes it is unfortunately. This only a recent development, so we did not know when you did your motor. It was being discussed, but all we knew was what the Silvertop engine did, not how. Quite a while ago, an owner fitted an EFR to a GU and got it all set up and dyno'd at about the usual power and torque figures. The motor carked it, and the owner fitted a Silvertop in its place. Normally it is difficult to compare one engine to another as every vehicle has a different airbox, intercooler, manifold, plumbing etc etc. But in this case all that stuff was taken off the GU engine and bolted on the Silvertop with not even a setting change to anything, and it made 900nm straight away. I am told it opened a few eyes up at the time! LOL

Once Oldmav was convinced it was the cam, I gave him my Silvertop cam to compare to a disassembled T spec engine he had access to. But that was only recently.
All good Shayne, fiddling with the cam timing is not something i would take a light hearted approach to, i may look at doing it down the track though if it proves to be fruitful.
 

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I don’t see why the cams wouldn’t be interchangeable if they are indeed the same.
The followers on the silver are about 5grams lighter, with the diameter of them being difference, length is the same as are the push rods.
I though I had some photos when I pulled both motors down but don’t, but remember taking some measurements and weights.
 

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For anyone thinking about doing the tooth move, pull the motor. Lol

I wouldn’t even think about doing that crap while in the car.
 

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GQ Dual Cab. TD42Ti with fruit.
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All good Shayne, fiddling with the cam timing is not something i would take a light hearted approach to, i may look at doing it down the track though if it proves to be fruitful.
Agreed, so Oldmav can advise if there was any stone left unturned, but I think he covered all bases. Pistons are different between the engines so he wanted to check piston to valve clearances.
 

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I don’t see why the cams wouldn’t be interchangeable if they are indeed the same.
The followers on the silver are about 5grams lighter, with the diameter of them being difference, length is the same as are the push rods.
I though I had some photos when I pulled both motors down but don’t, but remember taking some measurements and weights.
Lift and duration were the same specs, but camshaft is different and cannot be interchanged. I think it was to do with cam followers (lifters) being different, but not 100%.
 

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If I can be bothered I might pull mine out tomorrow and try it.

Also noted the 16g is MUCH quieter but is very smokey compared to the efr.
 

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Lift and duration were the same specs, but camshaft is different and cannot be interchanged. I think it was to do with cam followers (lifters) being different, but not 100%.
Yeah the lifters are different as I said but not sure why that would matter, they are about 1mm smaller diameter the silver ones.
did anyone try and swap or just said it wouldn’t work?
 

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Also silver v t pistons there is nearly 200grams weight difference, then lighter rods and lighter lifters.
id like to bet it’s a combo of things.
I might do a dyno run with mine once I’m happy with it and see what it does, all my rotating assembly is t gear.
 

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Sorry, no more info from me. Peter will have to provide the specifics. I cannot remember exactly what he said to me.

Boosted if you are going to tinker without Oldmavs confirmation of the details I would be very careful. Could be a disaster if it is wrong.
 

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Tdlyfe.
no different to any other day.
Cowboy tuned 🤠🤠🤠

Was going to crank it a few times by hand to check then just take a punt. That is untill I spent 3 hours trying to get that damn taper ring to come loose.

After that I just fixed my ac tensioner and aborted the mission a sd I go back to work in 2 days.

When I get back I'll think about trying again but with renoving the motor as simcoe said
 

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It appears that i may have finally gotten to the bottom of my smoke issue and lack of bottom end performance. I have adjust the timing just bees dick in the retarded direction. I wasnt even completely sure it had moved, it was so slight. Anyway took it for a drive and noticable improvement in bottom end performance (still nothing to rave about but definately better) and a reduction in top end performance but still nice up to 110kmph. Unsure if the smoke had improved though. It was still very smokey and i and im close to the bare minimum no boost fuel adjustment so i adjusted the starwheel spring base up a bit hoping to improve the smoke. Well unfornately it didnt help a whole lot, all it did was reduce the power. Anyhow, i was close to giving up, im convinced that the timing is where it should be if not very close and decided to wind the star wheel down to at least get it driving reasonably. Much to my surprise the smoke situation was improving , the more i was winding the spring base down. This was exactly the opposite to what i was expecting to happen as more fuel equals more smoke right? Well heres what i think has happened. The lack of fuel has failed to light the turbo properly causing the excess smoke through lack of air rather than typical overfuelling by the pump adjustment. Really silly mistake on my behalf but all the research that ive done on the subject pointed me in the direction of too much advance timing or overfueling from pump adjustment causing the black smoke but it appears that the extra fuel via the starwheel adjustment has fixed my issue. Anyway hope that helps someone else from making this mistake. Bear in mind i am not an expert, my explanation may not be correct but that is the only way i can logically make sense of what has happened. I still feel that the starwheel needs to be adjusted down further, so i am expecting the best results for me are still to come although ive noticed a huge improvement already.
 

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Yeh i have a ground down 1/4 drive socket for the bottom IP nut, stuff taking the vac pump off every time. Added a bit more fuel via the compensator and the no boost screw this morning and have made a big improvement and it actually has a lot less smoke. The other reason for the improvement in smoke i think is the change in driving style as i dont need as much right boot to get things moving. Its already hit 40 degrees now so im finished for today, will continue this later
 

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I worked it out fairly early that it’s one of those turbos that needs to be fed, not mashed so to speak. Wrecked a few pins with grinds etc.
Feed it right and it drives like a petrol.
 

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decided to brave the heat and go back outside for another go and wowee im about 95% there! It needed some no boost fuel, quite a bit actually and now shes spooling up like a champ. Since it drove better with the reuben pump with no preload at all on the fuel pin i had always assumed that it would be pretty similar with the ufi pump so i hadnt given very much no boost fuel at all. i had even ground the top of the fuel pin to give it even less, in an attempt to reduce the smoke. FFS bloody smoke screw threw me right off, winding it in has given me less smoke, go figure! Its all starting to make sense now. Cant believe its taken me so long to figure out what was going on.
 

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Silvertop cam timing change has now been done by Oldmav on a running T spec motor, and results confirmed. So there you go. Looks like a goer.
 
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