Thread: P38 4.6 What would you do?

PS, you can reduce the CR by grinding the shrouding out of the combustion chamber around the inlet valve. Theoretically this is desirable anyway as distance of the chamber wall should be the same as valve lift, and on a Rover it sure isn't.
You can remove probably 5CC from this area which would bring your CR down by about 0.5 points to say 8.75 , which should enable 91 octane.
Regard sPhilip A

Originally Posted by PhilipA

Just a seniors moment.. I was trying to remember the acronym for UnLeaded premium 95 (ULP?) No its PULP.

I think you will have trouble with 91 on a High comp engine, just based on reports of friends with high comp Discos who have trouble/pinging with 95 PULP.
The Commodore has a FAR newer combustion chamber design than a Rover /Buick V8 and a 5.7 v8 in a 1600Kg body does not have to work as hard as 4.0 in a 2300Kg or so body.
Its just a consideration if you intend to go bush.
Regards Philip A

It will be fine, the knock sensors will alleviate all pre ignition

I'd still run the better fuel personally though, as the knock sensors prevent the engine from pinging, but also allow much higher timing to be utilised on quality fuel, but filling up with 91 if its all thats available, won't be of concern

Thanks for all the help, I chose to go with High Comp, and I brough a faultmate, so I can reset all the adaptives.

Heres an update,

Engine arrived on Wednesday night. I came home from work early so I could be at home when the courier arrived. Hung around until 4:45 when I thought I had better ring TNT to find out whether it was still coming. This is what the conversation consisted of:

ME - "Just wondering where my package is?"
TNT - "It left Campbellfield at 5:30AM"
ME - "Well where is it?"
TNT - "Its back at campellfield"
ME - "Why?"
TNT - "No Reason, it went out on the truck"
ME - "So, it just got on a truck for a ride around the suburbs. Why was it not delivered?"
TNT - "No Reason, you can pick it up from the Depot"

ARrrrrrhggghhh!!! So I drove over to campbellfield, which took about two hours. Got there and the forklift lifted it onto the trailer. Geeee that timber pallet looks a lot smaller than the steel cage one I sent it on. TRS decided that they would like to keep my pallet. GGGRRRRRR!!

So anyway I finally started putting the manifolds on today, here are some pics at the end of today's work.





The last pic, is of the pieces of the Jigsaw puzzle, still to be put together. At this point I can't recommend TRS for their management skills, However I do firmly believe that the Motor they have built for me will be absolutely fantastics. Once the motor is running I will be able to comment further.

Here are the specs:
Rebuilt and Top-Hatted Block
PC216 Camshaft
New Lifters, Chainset
ARP Head Studs
New 9.55:1 Pistons
All asssembled and sealed to a long motor (just bolt on manifolds)
Total cost was just over $6000 AUD inc transport.

On a happier note, my faultmate arrived on Friday , so I'm just waiting on the activation codes.

Stu

Good to hear and hope all else goes well.

It's in.... well sort of. After a weekend spent in the garage we finally started lifting it in to the car at about 2:00pm today.





After much jostling around we finally had it sitting on the mounts half an hour later, by 3:00pm I started aligning the dowels to the gearbox and bolting her up. Does anyone know of an easy way to do up the botls. I could get to the top two and the bottom two, but the remainder seem to be very challenging. With a thud and a pinching of my palm, it finally closed the gap. We then bolted the torque converter up, and bobs your auntie, I started plugging things in. Tomorrow after work I will have another go at those hard to get bolts, and then its a matter of going over every bolt with the torque wrench.



I'm not trying to get it done for easter as it will have to be run in. What reccomendations on OIL should I used for the run in period? How long should it take? Any special precautions I should take before I fire her up?

Cheers

Stu

Some suggestions:

1. Oil: unless TRS tell you different, don't use a full synthetic for your new engine. Fill it with a good mineral-based oil such as Magnatec 10-40.

REASONS:

(a) you need the rings to bed into the cylinder walls properly...for this to happen they need to actually "wear in"

(b) the P38 doesn't have roller rockers... the "flat" faced lifters are actually machined when new with a slightly convex base because they need to be able to rotate slowly as they ride the cam lobes to minimise pitting. similarly the pushrods also need to be able to rotate.

Full synthetic oils such as mobil! are too slippery ...they preclude wear and rotation... in a new engine. (I hear that OEMs bench run their engines with mineral oil for this purpose and put full synthetic in after delivery...)

2. Don't fit the spark plugs until you have put oil in the sump and rotated the engine manually to get the oil circulating. I usually fit the serpentine belt then, using an electric drill with a 3/8 drive and socket to fit, I attach it to the alternator pulley retention nut with a u/j if necessary and turn the engine over a number of times in an effort to get the oil moving.

3. The first thing to bed in are the lifters/cam lobes. So when you are ready to fire it up for the first time, get it up to 1500 rpm and keep it there for 20 mins. If you have to shut it down, just turn it off, don't let it idle first.

4. Keep the revs below2500-3000 for the first 1500 km. Don't drive at steady revs for prolonged periods but try and vary the revs. Use reasonably long steep descents, holding the speed by engine compression, to lubricate the upper cylinder area (the oil is sucked into the upper reaches of the cylinders by manifold vacuum...)

5. Change the oil and filter at 1,500km (use same oil spec as before)

6. After 1,500 km gradually increase the revs to 4,500-5000 occasionally until you fell the engine has loosened up...then drive as normal!

Hope this helps

good luck!

Originally Posted by PhilipA

The Commodore has a FAR newer combustion chamber design than a Rover /Buick V8 and a 5.7 v8 in a 1600Kg body does not have to work as hard as 4.0 in a 2300Kg or so body.
Its just a consideration if you intend to go bush.
Regards Philip A

Good point... "mea culpa" ...I didn't quite think it through ....

cheers

hoges

IT RUNS!!!

Fired her up this afternoon, sounded awful for the first few minutes, oil pressure came up right away, and then ran at about 2000 for 20 minutes, after about 10min it rapidly quietened down. Just took it out for a gentle drive (still haven't let it idle for more than about 20 seconds), still feels very tight, filled the tank half way with 98 RON. I now remember why I love this car, so smooth and quiet.

Cheers

Happy Stu