Safe boost level for fd33t

tuggersbmx · Senior Member

Safe boost level for fd33t

Aus-Kiwi · Guru

I would limit bit to about 12lb ? Whats it drive like there ? Good ole boost control issue !!!

tuggersbmx · Senior Member

It was driving very well with the boost controller wound completely out but probably not safe. The controller is very old so just purchased a new one then will adjust properly during the week. I suspect I also have a boost / vac leak. Cooma diesel said a small boost leak would not cause any issues. It would have to be quite a large leak. I bought a smoke machine to try find vac leaks. Will research and try figure out best way to do boost leak. Will set boost to 12psi and try once new controller arrives. Mick

KJB · Guru

tuggersbmx wrote:
It was driving very well with the boost controller wound completely out but probably not safe. The controller is very old so just purchased a new one then will adjust properly during the week. I suspect I also have a boost / vac leak. Cooma diesel said a small boost leak would not cause any issues. It would have to be quite a large leak. I bought a smoke machine to try find vac leaks. Will research and try figure out best way to do boost leak. Will set boost to 12psi and try once new controller arrives. Mick

Be conservative in your Boost until you can measure accurately...there are no.half measures in "over Boost ..

" blow ups..." and little warning....the only certainty is it will cost a lot....!

KB

Jaahn · Guru

Hi :)
I will give you the safe question to answer and you can do what you like really !

What is the standard boost for that motor, you have the manual now ? 7 or 10 or what ? 15 is very high IMHO.

Is the fuel pump controller working to give extra fuel for the higher boost or is it limited ? It is the fuel that makes it go not the extra air !

How good is that motor, is it excellent condition or is it getting tired. In your bus it will be working hard most of the time so do not over do the boost if you want a reasonable life.

How good is the clutch ?

Is the cooling system working well and in good condition ? Most important in an old bus !

Life is full of compromises now is the time to make yours !!
Jaahn

PS Engines do not 'Blow up" often. They usually just die and stop and then you restart them with lots of money furious

-- Edited by Jaahn on Sunday 6th of June 2021 09:24:21 AM

-- Edited by Jaahn on Sunday 6th of June 2021 09:31:27 AM

tuggersbmx · Senior Member

Yep...don't plan on taking the rig out for a drive until new boost controller arrives and EGT sensor and gauge. Then will install both, reduce boost to 10psi and check everything.

Peter_n_Margaret · Guru

Several years ago I had the Perkins in the OKA fitted with a new turbo. It now blows 17psi with conservative fuel and EGT settings (boost comes from rate of burn of diesel).
We were actually hoping for 20psi at the top end, but we did get 7psi at 1500 rpm which is much more valuable to us.
Cheers,
Peter

tuggersbmx · Senior Member

I will check the manual I have again but I don't think it advised boost level. My engine is in good condition. Put a new clutch in when swapping engines. Reconditioned the injectors to spec crack pressure. Radiator is in good condition. Engine sits at about 80 to 85 degrees. Blows a bit of white smoke on start up but once warmed up no visible white or black smoke that I can see. The boost componsator at the back of the injector pump should be working fine. Am I right by saying it's job is to match the right fuel to the boost? I definitely want it to run safely and for a long time. Mick

Jaahn · Guru

Hi Mick smile

I would be sure there is a reference to the boost in there somewhere. Possibly in the injection pump calibration as that compensator will be something that needs setting during calibration as will the max fuel delivery. You are correct that it is to match the fuel to the boost but it will have a maximum setting for fuel done when the pump was calibrated for the max factory boost setting.

Glad to hear the engine is good and working well. 10 sounds like a good boost to me and see how it goes, but I am no expert. smile

I believe Peter would have a Perkins in his OKA and they are renown for being tough working engines that will take a pounding. biggrin

Jaahn

-- Edited by Jaahn on Monday 7th of June 2021 12:43:17 PM

tuggersbmx · Senior Member

Ok so the manual states the following: When checking turbo make sure that the it does not go past 83.3kpa (12 psi) Engine should be running at 2500 to 3000 rpm It then states when inspecting the by pass valve then air pressure above 14psi may damage the diaphragm. So best bet would be fine tune to 12psi?

Aus-Kiwi · Guru

Diesels are different to petrol engines !! If theres not enough fuel ? It simply wont make the power ! It is basically what controls the engine ! Boost or power level is more a concern with head sealing !! Why many fit ARP or similar brand head STUDS . Yes keep an eye on engine temps . Should only rise on long hill palls if anything !! My 6.5 GM pulls all day on 5 to 8lb .At the upper rpm with load . Boost gets to 15lb . From memory your engine loves rpm too ! So youll have a little Jekyll and Hyde type power band !

tuggersbmx · Senior Member

Yes this engine does like to rev high. Could actually do with another gear and I'm also redoing the sound deadening to give my ears a break. On amayama it states that the FD33T came out a 6 speed box but I definitely cannot find 6th gear! And I would not think reverse is counted. So the box has either been changed or I am just a ****ty gear changer haha. I have even re done all the washers and plastic grommets in the selector rods and readjusted the rod positions to make gear selection better. New clutch too. If I could find a 6th gear I'd be quite happy. When I get time il check the numbers on the box just to confirm.

KJB · Guru

tuggersbmx wrote:
Yes this engine does like to rev high. Could actually do with another gear and I'm also redoing the sound deadening to give my ears a break. On amayama it states that the FD33T came out a 6 speed box but I definitely cannot find 6th gear! And I would not think reverse is counted. So the box has either been changed or I am just a ****ty gear changer haha. I have even re done all the washers and plastic grommets in the selector rods and readjusted the rod positions to make gear selection better. New clutch too. If I could find a 6th gear I'd be quite happy. When I get time il check the numbers on the box just to confirm.

You may have to look into a diff. ratio change. (Could be a cheap option...)

tuggersbmx · Senior Member

Already have done the diff change to a highway diff instead of city.

KJB · Guru

tuggersbmx wrote:
Already have done the diff change to a highway diff instead of city.

Was that the only "other" ratio available........? Sometimes there are more than one.....

tuggersbmx · Senior Member

Ummmm. I'm not sure. I swapped the FD33t engine and whole drive train out of 1 bus to my bus. I had an ED33 with 10 speed splitter and city diff. Was horrible.

Aus-Kiwi · Guru

Could step it up with tyre or wheel change ? These engines didnt have much low rpm torque !!! Nothing like its bigger brother 4.2 !!