Engine changeover

[Pokey]

Well I am getting close to making my decision on the change from the blown 6354. I am looking at a Perkins 6354.4 turbo at the moment. To make things most economical I am considering getting the engine swapped out near where the bus is parked up. My concern is the space needed for the turbo. I think that I will need to make some mods to the engine box but would prefer to do this myself and in my own time. What I was wondering was if I do the following

a) Swap the engines
b) Take the turbo and the inlet and exhaust manifolds off
c) replace them with the manifolds from the old 354 (supposed to be all the same heads)

Will it damage the motor running it without other mods e.g. fuel pump, injectors etc?

If Ok I can then drive the bus home to Brissy and take my time rebuilding the engine box, fitting heat shield and insulation, get the exhaust replaced as the existing is 2 1/2"and the dump on the turbo is 3". I would then get the HP increase I want without having to pay for the fiddly bits that I would have to do if all fitted up in Central Qld.

[Dot]

Hi Pokey, I reckon the mechanical ones are all off air at the mo and doing some travelling but they won't be far away to answer you..

[Greynomad]

Pokey,

Save yourself a shirtload of work...
Buy a bigger rubber band!


Seriously, I suspect the engine would appreciate a lazy run without the turbo ramming air into it.
Can't see that it will do any damage.

However, I'm not a mechanic. "All care; No responsibility" if you act on the above.

Good luck with your conversion...

[Pokey]

Any of the diesel specialists like to comment on this? One engine I am looking at is a short motor so will need to switch injectors, pump and manifolds. I understand that the dot 4 in turbo build has a slightly bigger changer to allow for the increased feed of air. If I use my existing pump which is set for non turbo I would expect that there shouldn't be a problem with over fueling and smoke but I am just working from things I have picked up, not from engine management knowledge.

I am really not sure what to do so need all the considered advise I can get. Have thought about going Isuzu but it will entail even more work, besides different mounts etc as they are generally 24V so have to change the electric setup. That sounds to expensive to have done in a workshop so a straight Perkins swap is still the favourite. I will then need to pull the manifolds off, get the injectors and pump reset and probably expand the engine box to fit it all in when I get home. Then need to get a new exhaust fitted to suit the 3" of the turbo etc etc ad infinitum.

[BruceS]

I had a chat to my experienced mechanic & he assured me it is a simple foolproof job to swap your injector pump into the new motor to drive it home.
The spline will only fit in one place. No tuning or adjusting needed.
He also suggests you'd be better off not going turbo but doing a 'mod' to the motor that will give it equivilant extra power to what the turbo will achieve.
Seems like you're going to do it 'your way' regardless of advice anyway. Just a pity you don't live around the corner from me!

PS. please double check what you do get with a 'short' motor. You might need your head as well to swap?

[T1 Terry]

If it's a factory turbo engine and injector pump, the front of the pump will have an aneroid (not sure of the spelling and my spell checker has died) If it has this fitted, there will be a pipe from the inlet manifold to the front of the pump that bolts on to a large diameter cap. this is a diaphragm with a linkage underneath that increases the fuel when the turbo increases the intake manifold pressure, no turbo, no pressure increase, no black smoke and over fuelling.
If it's an after market turbo, the pump has been fiddled to add the extra fuel all the time, clouds of black smoke when off boost, it will need adjust back without the turbo. Perkins engines don't seem to suffer from over fuel as far as damage goes, in the early days they tuned them by the length of the flame out the exhaust stack and the flickering tip on the end ah the good old days, they'd shoot you these days.
As far as the exhaust pipe, 3 inches from the turbo to the first muffler or about half way past the gearbox, (dump pipe) 2 1/2 inches from there on. Make heat shields from an appropriate sized stainless saucepan cut to fit over the turbo exhaust snail and bolted to the exhaust flange bolts. The dump pipe can be heat shielded with pieces of thin stainless plate curved the shape of the pipe attached to hose clamps with small bolts and a few fibre washers to act as a spacer, wrap the hose clamps around the pipe and position to suit. Might need a shield over the muffler but the rest of the exhaust should be ok.

[John M]

My diesel experience comes from driving and maintaining my own trucks, and in my opinion (and at risk of argument), Show me a truck that is making money, and I will show you a Cummins engine.
From what I have been told, most diesels will benefit from a pump and injector calibration regardless, of their age. A well known Trucking company used to change (rebuild and calibrate) pumps and injectors every 100,000 km whether they needed it or not, the number crunchers stated that the fuel savings alone more than covered the cost. (Normally attempting to placate the number crunchers cost a lot more than they saved).
The old 6/354 Perkins was a tractor engine that has been used in every make of trucks for 50 years (or more) I have seen them pulling double trailers in the old Inter, as well as a lot of the old Pommy trucks that were running up and down various highways, back in the days when 50 mph was the speed limit and 30 mph was acceptable on the outback roads, and in condition that would see a lot of the modern Blacktop cruisers fall to pieces, even at those speeds. The old Perkins just kept on keeping on. As a sign of respect most of the Japanese Diesels were initially Perkins clones.
From what I remember from my Perkins days (Commer and Acco) one of the things they hated most was over revving, yes they would run out to 3000 rpm, but would last a lot longer and run a lot happier if the red line was set around 2200 rpm. (this was in common with most diesels) as does my Isuzu (another clone). The modern trend to higher revving smaller motors works, with the modern technology in metals, castings and machining, but try it with the older motors and all you are doing is building a bigger hand grenade. Give me a bigger motor working easier any day.
What I am suggesting is refit a Perkins get your old injectors and pump reconditioned and calibrated, and keep it going for another 50 years, my only question with the turbo model, is whether the compression ratio is same as the naturally aspirated version.

[T1 Terry]

The Perkins Phaser engine will run quite happily without the turbo fitted, you won't see the 210hp but it will keep plodding on up the hills and these engines were decompressed to suit the turbo, there must be enough base compression for the engine to start and idle. The older Mack engines ran 28psi plus boost yet still idled with no boost, so total cyl pressure being too high doesn't seem to effect the engine performance or life, just the emissions, the NOX goes sky high under high cyl pressure because the combustion temp is so high. Most early turbo diesel engines didn't have a waste gate to control boost pressure, the fuel load seemed to be the only control, the more fuel, the higher the boost, the more power, till it over heated and melted the pistons, a popular Mack trick.
The Perkins engine does not like to be pulled down to far in the rev range under load they will hammer out the bearing if you do. the crankshaft is very suseptible to cracking as well if a bearing gets a little on the loose side.

The old adage about show me a truck making money seemed to have your favourite engine type inserted in the next line, I'd say the Cat engine would be the one that fitted the saying the best

[BruceS]

Around about now I'd expect Dot to step in with "mine's bigger than yours" !!! (ps. I saw it!!!)
Times do change ........ yes it was Perkins, then it was 1418 Mercedes, then it was 903 Cummins and so on it goes!
Pokey I'll quiz my man over the weekend & get back to you.

[T1 Terry]

Around about now I'd expect Dot to step in with "mine's bigger than yours" !!! (ps. I saw it!!!)
Times do change ........ yes it was Perkins, then it was 1418 Mercedes, then it was 903 Cummins and so on it goes!
Pokey I'll quiz my man over the weekend & get back to you.

Ah, the 1418 Benz, the only truck that had a calendar instead of a speedo I'm not sure if it was the fact they went for ever, or just seemed that way because it took so long to go any where