1hz turbo camshaft

[cheeckyboy31]

does anybody have tech specs on both a 1hz and 1hdt camshafts? i am wondering if it is possible to grind a 1hz one to 1hdt specs. i know the 1hdt has 1mm less lift on the inlet lobe and it is much cheaper to do that than buy a 1hdt cam $480.00 from engine australia. i am building a turbo hz engine that should go real well and live, shame it was not a cheap task.
thanks

 

[Entaran]

Why change the cam?

Plenty (and I mean LOADS) of 1hz's with turbo's running n/a cams.

The N/A cam will be more responsive down low anyway.

 

[Z()LTAN]

sorry for the hyjack bro, but im real interested in what your doing to your engine.

Ive just purchased a 2007 1hz engine with only 5k on the clock and also looking at turboing and water intercooling.

Wanting some good boost, around 14-16 psi with pump wound up and boost compensator utalised.

Eager for some info mate!

 

[cheeckyboy31]

entran,zoltan,
the cam in a diesel works like it would in a petrol, the grind dictates the behaviour of the engine, along with other things like exhaust, fuel timing advance curve.... lower lift and duration on the inlet will reshape the power curve. at the moment i have low boost until the midrange then it has more than usable. to drop the inlet a bit would encourage better low end responce and as the boost picks up there is less time to fill the cylinder, match that with les fuel and you have changed the shape of the power curve to what i want, more down low and ls in the fat spot. with 22.7:1 compression a high peak torque and with that power the peak cylinder pressure reacts on the big end bearings with predictable results. what i want is lots of power every where, to get that without considering the longevity cost is going to make life expensive. with what i am building i am going with 1hz-t pistons (ceramic coated), 1hd-t rods, small turbo-which needs something to prevent overspeeding and life reduction, high egt's. i won't be dropping the compression to 18.5 as with the 1hd-t and factory 1hz-t as you do lose off idle (boost) power too much, probably down to 20:1. turbo diesel needs less lobe overlap on the cam (scavenge time), enough ex duration to prevent choking up high and a short duration exhaust opening (stronger gas pulse) helps to spool the turbo at low revs, especially with a split pulse turbo and manifold(3 cyls to one side and 3 to the other).
i also will be setting the static pump advance to the more advance end of spec and increasing the injector cracking pressure a few 100psi, this needs to be fine tuned on the dyno.

 

[cheeckyboy31]

the water intercooler is a good idea for a 4x4 until you get up in the boost and boost temps to match, i work for caterpillar and i have seen the switching points they use for which type of intercooling, if i find it again i will post it. i am also trying to get total seal rings for this engine to see how the blowby/crank case pressure goes. as long as they don't increase the parrasitic load too much i will be happy.

 

[Entaran]

1hz pistons don't mate to 1hdt rods.

Sorry to tell you.

I had to go forged 1hdt pistons (from JE) with 1hdt factory (new) rods.

I still have 22.7:1 compression.

 

[drexx]

1hz pistons don't mate to 1hdt rods.
[...]

That's quite true. When my HZJ-80 bent its con rod #5 due to water ingestion, the most available second-hand part for me was one from a 1HD-T. The 1HD-T conrods were significantly bigger than the 1HZ's. And I think the 1HD-T crankshaft looked bigger too, but I didn't get to compare them side-by-side. Oh yeah, it did look quite possible that the 1HD-T cylinder head would fit the 1HZ.

Which made me wonder then, would the 1HD-T crankshaft, conrods, pistons, camshaft, cylinder head, and injection pump work well together on the 1HZ?

 

[Entaran]

I have a 1hdt crank, rods and pistons with a 1hz cam, head and pump.

Works fine for me.

 

[cheeckyboy31]

"there's so much confusion here said the joker to the thief" 1hz pistons don't go on 1hd-t rods, that is true. what i wrote is that i am going to use FACTORY 1HZ-T (from a coaster bus) pistons, which have the larger wrist pin the same as a 1hd-t rod and the correct top for a pre comp engine ie same as std 1hz. you can't run 1hd-t pistons with a pre comp 1hz head as you would have two combustion chambers and very low compression, trust me on that one i have worked on nothing but diesel (mostly CAT) for the last seventeen years, except for ford clevlands and my two stroke race bikes. also i have spoken to Dean Tighe today, Tighe Cams brisbane, he has confirmed my thoughts on the cam spec changes for turbo usage and added that by advancing the exhaust event we can pulse the turbo even better than by shortening it. entran, out of curiosity, did your forged 1hd-t pistons look flat on the top like a 1hz? or did they have a deep hole in the centre? Drexx, 1hd-t crank is the same as a 1hz and the block is the same, if you had a cracked head, stuffed pump & injectors and needed a rebuild you could make a 1hz into a 1hd-t while you were buying your parts

 

[cheeckyboy31]

entran, you question why i am doing all this, part of the reason is i am off the tools now working as a technical trainer for Cat, as part of my teaching qualification i have to remain current in my industry, i also am a greenie so if i can reinvent the wheel for great power and efficiency with an engine that uses a primative fuel system, i can run waste vegetable oil and gas through it and still pass a new turbo six cruiser up hills....spins my wheels

 

[cheeckyboy31]

as it is now i get 1300kms out of 140l of diesel,the new engine will be set up to run Waste Vegetable Oil and gas. WVO is often free or 50c per litre, gas is not much dearer, i rekon that a few extra thousand building a more efficient engine will be easily recouped over the life of the engine on fuel costs. 500,000km i expect. the planet may also be better off too

 

[Dougal]

you can't run 1hd-t pistons with a pre comp 1hz head as you would have two combustion chambers and very low compression,

I was wondering about that one too. A combustion bowl in the piston and prechamber in the head makes a very big dead space.

I'm still curious as to the reasons for the cam swap.
If the HD-T cam has lower lift (I may have read wrong here) but more duration, would that give better VE than a high lift and shorter duration?
What are the tradeoffs using large duration with diesels? I know overlap is a very bad thing (my Isuzu has almost none) when you've got turbo drive gauge pressure at roughly twice the boost.

 

[cheeckyboy31]

my stock 1hz with DTS turbo has no more power where i really wanted it-down low. it has heaps in the mid range. maximum torque, read (engine stress) has been increased, don't get me wrong it goes much better than it did NA. 1hd-t cam has less inlet lift, not sure yet about duration but i think it will be same or less, diesels run more overlap than many petrol engines. going turbo you can use less overlap as you are pushing the air through not sucking it. overlap cools the valves and cleans the pot, on a natural aspirated eng you rely on pressure waves to help move air in and out like tuned length extractors, turbo it matters less a cam that produces good low end power has less lift and duration and overlap than a more racey one. i want less peak torque, more torque lower down. fringe benefit is my small turbo will not sit at peak speed as much with the waste gate open when cruising down the high way basically i am trying to reshape the power curve for a more even spread of power and the 1hdt cam is from almost the same engine (volume wise) so i will piggy back the factorys research, they have more money than me

 

[Dougal]

my stock 1hz with DTS turbo has no more power where i really wanted it-down low. it has heaps in the mid range. maximum torque, read (engine stress) has been increased, don't get me wrong it goes much better than it did NA. 1hd-t cam has less inlet lift, not sure yet about duration but i think it will be same or less, diesels run more overlap than many petrol engines. going turbo you can use less overlap as you are pushing the air through not sucking it. overlap cools the valves and cleans the pot, on a natural aspirated eng you rely on pressure waves to help move air in and out like tuned length extractors, turbo it matters less a cam that produces good low end power has less lift and duration and overlap than a more racey one. i want less peak torque, more torque lower down. fringe benefit is my small turbo will not sit at peak speed as much with the waste gate open when cruising down the high way basically i am trying to reshape the power curve for a more even spread of power and the 1hdt cam is from almost the same engine (volume wise) so i will piggy back the factorys research, they have more money than me

I'm trying to follow but I'm a bit confused.
At the start you mention your DTS turbo doesn't give enough low end boost.
But then later you say the turbo is small and runs at peak speed cruising on the highway.
I haven't seen many turbo diesels which are running max boost on a highway cruise (unless it's moderate uphill), their wastegates are closed in these conditions.

IMO the best way to get what you want (more low end torque) is by modifying the turbo setup. Does DTS use garrett turbos? What is the model and exhaust A/R?
Does CAT have a variable vane off an engine with similar air consumption that you can substitute?

 

[roscoFJ73]

"there's so much confusion here said the joker to the thief" 1hz pistons don't go on 1hd-t rods, that is true. what i wrote is that i am going to use FACTORY 1HZ-T (from a coaster bus) pistons,

Where does this Coaster bus with a 1HZ T exist? Someone showed a page from a parts book showing a 1HZ T but it looked like a mis print to me.

If you want turbo pistons for a 1 HZ ,ACL make them and sell them through Repco

 

[Entaran]

I'm not using factory 1HDT pistons. I'm using forged JE Pistons to suit a 1HDT engine. They are FLAT ontop, 0.50 oversized as well.

The engine I rebuilt had... a heatcracked crank (useless, throw it away), bent rods #3 and #5 cylinders and some scoring in the bores... hence 050 over now. Out of neccessity, we got a 1HDT crank (might be a 1hz crank but I think it's a 1hdt), definately has 1hdt rods but the pistons are 100% custom not the factory items.

My engine still has 22.something:1 compression. And new precom chambers up topside.

 

[hdj105]

Where does this Coaster bus with a 1HZ T exist? Someone showed a page from a parts book showing a 1HZ T but it looked like a mis print to me.

Well bugger me, someone in the world got a 1HZT Coaster. It is in the parts book!

They still used the std 1HZ cam though.

 

[cheeckyboy31]

Not Sure Where The Coaster Bus Is Sold But I Can Get The Pistons From "engine Australia" For $90.00 Each
The Turbo I Have Is A Mitsubishi Tdo5 Which Was Part Of The Dts Kit For This Vehicle. when i say it is small, it was reputed to be the best for spooling up early, it uses a TD04 mtg flange. It Does Not Sit On Full Boost On The Highway But Around 4-7 Psi Depending On Gradient And Head/tail Wind.. when you put the foot in on the highway the note changes but it does not accelerate much, feels like it is fighting itself
Entran, How Much Were These Pistons You Got?

 

[cheeckyboy31]

The Turbine Hsg For The Turbo Is Apparently Custom Made For The Kit And I Could Not Find Any Info, it has the seperate wastegate dump plugged with a disc and tack welded in from new, the outlet from the turbine housing is 50mm I Looked Inside The Hsg As Well, Variable Vane Or Hsg Clearance Turbos Are Not Something I Have Seen On Cat Stuff, Mind You I Usually Work On Mining Size Gear So Those Ones Are Too Big, I Have Had A Quick Squiz Around The Second Hand Yard But There Are So Far Only Complete Engines And The Smallest One Was 6.6l....that Would Go Nice In The Cruiser

 

[Dougal]

Are you running an EGT gauge?