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Originally I was all keen to rip the TB42 out of my Maverick and shoehorn a Clevo into it.
After researching some of the info around on it and remembering back to the hassles I had with my V8 hiluxs getting everything to run sweet and sorted out I dont know if I can be stuffed.
My reasoning is the TB42 is a torquey donk that actually pushes the old rig along ok. It would go much better with a ratio change but (35's with 4.11's )
Anyway my question is. What are the head cracking issues that affect the TB42's and is there anything that can be done to correct them?
Im undecided at the moment whether to shove a good set of pipes on the TB and fit a pertronix and later on rebuild the motor for more grunt or to battle on and do the Clevo conversion soon.
I dont want to spend good coin rebuilding the TB and having head issues with it , when I could have put that money towards doing the Clevo and having hassle free power.
Any input peoples?
If they're on gas the head cracks over #6. If they're not on gas the gasket blows out. Most TB42s get 200,000 klms per head. Head replacement costs approx $2000. You do the math...
Weekdays - Prado GXL D4D with some stuff
Weekends - Mav shorty with lots of stuff
my head cracked in 2 places iach about 4'' long , so thats why i decided to fit the 304 in its place....... best decission i've made , bit the bullet and stick the V8 in it
88 GQ SWB 5''SUS LIFT 60MM BODY LIFT, FRONT LOKKA, NOW WITH 304, ...... :D
Mine blew a gasket at no.6 on gas and getting pushed very hard and hot whilst blown for some time. Cracked head or blown gasket comes down to luck i think. Mine cost me a couplahund for resurfacing, valves, springs and gasket kit. the rest done by myself
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Premiers 1999, 2007, 2009
Spoon 2010
The head issues can be linked to poor cooling system design
but this can be overcome with a few mods and the engines made to perform more efficiently and reliably. They are not a state of the art
engine for sure but you'll have to weigh up the costs of conversions Vs
rebuild/modify.
Custom Barwork
Cages built to CCDA specs
Turbo and intercooler systems for diesel and petrol.......PM me.
Centavic Performance 4WD
my tb42 head cracked at 325,000 ks. ripped head off found cracks in 5 and 6 and gasket round 6 was gone too. bought a new head casting, had it shaved and a bit of a clean up, new firmer springs with a hi flow water pump. had a air bleed kit fitted to cooling system. all up 3000 but now my shorty goes sweet an runs cool. very underestimated motor the tb 42. money was not a factor and i was gunna do conversions and turbos etc but honestly no need now.
viperguy wrote:my tb42 head cracked at 325,000 ks. ripped head off found cracks in 5 and 6 and gasket round 6 was gone too. bought a new head casting, had it shaved and a bit of a clean up, new firmer springs with a hi flow water pump. had a air bleed kit fitted to cooling system. all up 3000 but now my shorty goes sweet an runs cool. very underestimated motor the tb 42. money was not a factor and i was gunna do conversions and turbos etc but honestly no need now.
Yes, Ive done the exact same head modification to my TB42 and it performed significantly better in cooling efficiently and slightly more power increase aswell. It cost me $3000 nearly five years ago.
But, what finally made me sell the vehicle was the 30litres/100klms of LPG it use to burn at very gentle driving and 40ltr/100klms when wheeling. And no amout of tuning could ever improve these figure at all!
So if a V8 conversion will give you better fuel consumption figures and better power then, go for it.
What do you want from an alloy head?? I dont know of any that last any better if not looked after all their life. I've done more Falcon heads, VL heads, Toyota Corolla and Camry heads(the 80 and 100 even erode the deck meaning an engine tear down and decking) and in 5-10 years we'll be doing Gen 3 heads . Usually corrosion, overheating from water loss and blocked radiators and other thing are the cause, my Mav engine is 320k old never apart and has been running 14-20 psi boost for the last 3 years. Cracking is usually a result not the cause of overheating or other forms of abuse, poor tune(especially on LPG) tight valves. Dont turn your head into swiss cheese and create another 30 potential water leaks with drilling a perfectly accuptable design. Find the problem and fix it.
chimpboy wrote:Where was that thread the other day about drilling between each cylinder and tapping into the water jacket for better head cooling..?
Sounded like decent idea.
i have actually seen this done, and thought, WTF. i think you would get a better result with a diesel radiator (slightly larger) and a higher volume water pump and regular maintenance of your cooling system. Honestly imo the tap idea looked like a waste of time and money the way it was setup
Maverick. Unlocked on 35's MOTTO: Lock, Stomp & Hold on
When I did my head, I noticed the head gasket had smaller holes in it and even blocked of some water passages. I asked the guys machining my head it they thought I should cut them out and they said not to as Nissan must have had a reason to do it like maybe limit coolant flow to the head. Maybe the heads are getting too hot? Anyone else noticed this and maybe cut theirs out?
[quote="bazooked"]can i use a mate to position while i screw? :twisted:[/quote]
my ol mans a mechanic and i asked the same thing when i did my gasket and i got the same response they must have a reason for it, somethin to do with coolant paths and cavitaion in the system causing bubbles and inturn uneven cooling and overheating
All head services in Braeside Melb do a head mod for TB42. They drill into high point of water jacket above each exhaust port to bleed out trapped air bubbles and to give better coolant flow ,especially for cyl 5 & 6. They fit 6 hoses back to a combiner and into radiator. Also fitment of a hi flow water pump is recommended as they say orig one is crap .
Looks like a plumbers nightmare.
So far I'm up to 195000 km, water pump changed out and waiting for head to go bang.
But have seen fully mod'd TB42 back in shop with blown head ( owner let coolant level drop and tb42's need full radiators)
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, so thats why i decided to fit the 304 in its place....... best decission i've made 
