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View Full Version : New Head or Rework the old one



PJHarps
16th October 2012, 06:13 PM
hey guys i have a TB45 and im having the same problems as a lot of other people and as suggested by threedogs and had suspected myself it looks to be the head.

My question is should i buy a brand new head with valves etc ready to drop straight in (1500-2000 dollars) or should i have my head reworked as i have a friend whos father can redo it valves the lot for 700 bucks. i am not doing the work but getting a mech to do it who said the alloys in the old head my be fatigued and warp again in the next few years so that steers me towards new but the dollars steer me the other way as im an apprentice money is tight.

Thanks in advance
Paul

Bigrig
16th October 2012, 06:19 PM
Hmmm - isn't the head on the TB45 (and 48) less able as it were to be machined due to walk thickness? I had my TB42 head machined and opened up the chambers, but that added about 21cc and left about 8-10mm of wall - I was I the understanding the 4.5 was not as able to be machined (which will lower compression also - the reason I did it for the turbo)??

Happy to be wrong mate, just double check it can be done (as in, worthwhile to be done weighing cost v benefit) before laying out your hard earned ...

Good luck with it either way ...

threedogs
16th October 2012, 06:22 PM
The old rock and a hard place question. If you're able to buy new do they have gas heads???

PJHarps
16th October 2012, 06:28 PM
yeah running gas

PJHarps
16th October 2012, 09:03 PM
not sur if they have gas heads i will be chasing it up to find out as i really only run petrol when it starts and when i run out of gas so its on gas 99% of the time

Bob
17th October 2012, 08:12 AM
Try
Wave Hill Engine Services in Lilydale Vic. Google Wave Hill Engine

Here are there specs for a reconditioned TB45 Head

FULLY RECONDITIONED Nissan TB45 cylinder head
Set up to our Turbo and High Torque LPG spec's.
We start with a good secondhand cylinder head , then ,
Hardness test , Pressure test , Crack test , Strip , Chemically clean acid dip ,
K/Line valve guides , Serdi 3 way cut seats ,
Serdi flycut combustion chamber to unmask valves , Serdi throat ports ( also known as pocket port )
Second hand Valves , Valve springs , Retainers , Collets and spring seats are hot tank acid dipped
Valve are buffed , Valve stems linished , Kwikway reface valves , Kwikway tip valves
Comec machined with Diamond tip , final cleaned for assemble , valve spring pressure checked ,
Assembled with new valve stem seals

PJHarps
17th October 2012, 04:03 PM
did you mean cave hill engines. i have called them and more then likely buying 1 of their high torque lpg spec heads tomorrow or the next day hopefullly it will fix my dramas and give that bit extra :)

threedogs
17th October 2012, 04:26 PM
think thats the right choice, gives you warranty too I would think, Gas kills motors IMO. but S/S inserts etc will see it last a bit longer.
Turbo next? big power

PJHarps
17th October 2012, 05:56 PM
yeah i do wanna turbo it but i will have to look at the cost. i will be fitting a snorkel and exhaust next though i think as thats a fair bit cheaper to start with thanks for they ideas and lets hope she is good after the triple bypass :)

The BigFella
18th October 2012, 05:16 AM
dont agree with you TD on lpg wrecks engines, mine has covered 556,000k's now and still all original except for starter motor, power steering pump, alternator and the like.
The engine has only just started to show those tell tale signs of needing attention, has developed a slight miss at idle and starting to backfire on the rundown when the throttle is opened.
All unleaded cars are suitable for lpg these days, remember unleaded is a dry fuel like lpg.
If your hesitant you can run an upper cylinder lube like flash-lube for peace of mind, I do,,,,,,,,,,,,,,,,,,

threedogs
18th October 2012, 05:57 AM
Point taken most engines I saw totalled were not OE but mainly conversions using older motors, but the run huge temps if tuned leanish.
Anyway think gas may have run its race, prices to me seem way to high atm. Isn't to Gov putting price to $1 a litre next year??

Bob
18th October 2012, 06:00 AM
did you mean cave hill engines. i have called them and more then likely buying 1 of their high torque lpg spec heads tomorrow or the next day hopefullly it will fix my dramas and give that bit extra :)

Yes that is who I meant.
You will be impressed as my 4.5 now holds on longer on Hills and better pulling Power.

threedogs
18th October 2012, 06:13 AM
What style gas system do you have Bob, as you know some are better than others,
Is it possible to fit the sequenctial injection on the efi petrols ? I think these give good
power all the time minimal loss.

Bob
18th October 2012, 06:32 AM
What style gas system do you have Bob, as you know some are better than others,
Is it possible to fit the sequenctial injection on the efi petrols ? I think these give good
power all the time minimal loss.

Mine does not have sequential injection.
It starts on Petrol and automatically switches to Gas after warm up.

I do not notice that much of a difference in Power between the two Fuels but then again my Motor is tuned more for Gas than Petrol.
I leave the Tuning to a LPG Gas Specialist and I obtain quite good results in both Power and Fuel Consumption

The BigFella
18th October 2012, 06:40 AM
I also cant feel much difference if any between lgp and petrol.
Ive got mine "turned up" a tas (runs richer) for pulling.

As for cost, if lgp reaches $1.00 per litre I will most likely pull it out and replace with long range fuel tank,,,,,,,,,,,,,,,,,,,,,,,,,,,

Bob
18th October 2012, 07:30 AM
Just remember to tighten the Head down in accordance with the Manual.(Very important and time consuming)
Also New Head Bolts

PJHarps
25th October 2012, 10:07 PM
just a quick update guys. i have a new head from cave hill engines turning up tomorrow hopefully :) and the old girl(my GU) goes in monday for her surgery im getting the mech to throw in a new radiator a new viscous coupling in and flush the water jackets out while he is doing everything so about 1-2 weeks time i should have an answer to what was wrong and if its fixed... till then its the harley for transport.

Bob
26th October 2012, 07:41 AM
just a quick update guys. i have a new head from cave hill engines turning up tomorrow hopefully :) and the old girl(my GU) goes in monday for her surgery im getting the mech to throw in a new radiator a new viscous coupling in and flush the water jackets out while he is doing everything so about 1-2 weeks time i should have an answer to what was wrong and if its fixed... till then its the harley for transport.

Hope it all goes well. You will be impressed with the increase in Power.
Cave Hill Engines know their stuff

PJHarps
14th November 2012, 07:08 PM
hey guys new update. i got a bare head from cave hill engines.(feel no power difference) and had a mech put in the new head while at it he replaced the valves, gaskets, new cooling switch for the thermos, plugs and leads new heater hoses, air filter, radiator cap and had the radiator flushed and had hydraulics for the clutch fixed up. and after 2 days bam it overheats again. 4K spent for nothing. so farking pissed off. so im back to square 1. does any one have any ideas of what it could be seeing all the things done above. also its not using coolant and not boiling over. could it be the temp sender or the temp gauge( the motor does feel very hot when i open the bonnet or could it be it is running rich or lean that would cause it i am running dual fuel but runs on gas 95% of the time

Edit: also a new thermostat

The BigFella
15th November 2012, 05:49 AM
not trying to say the obvious but have you tested the temp (hand held temp gun) when it indicates its hot?
might be as simple as the temp sensor not working.
If it isnt boiling and still indicating its hot, Id be changing the sender unit.

Bob
15th November 2012, 07:54 AM
That is disappointing . Is the Motor tuned by a LPG specialist as I find most mechanics have no idea how to tune for LPG.

PJHarps
15th November 2012, 08:55 AM
@ the bigfella i havent checked with a temp gun but im having that done today and thinking i will just throw a new temp sender in as they arnt to expensive, the head work wasnt all for nothing though it needed to be done i now have no bubbling in the coolant and the mech said the gasket was shagged just a shame i got the expensive part done and it didnt stop the problem.

@ Bob im going to book it in for a tune with a specialist when i can find 1 around the brisbane area soif anyone has 1 they could recommend that would be great.

lets hope its just the sender :) thanks for the advise

lhurley
15th November 2012, 04:28 PM
Ive heard that autoart down at capalaba is the place to go. If you could post back on here or just pm me about the gas place you choose that would be much appreciated as i need mine done too. Thanks in advance.

PJHarps
15th November 2012, 08:52 PM
ok list of things changed.

1. New head - vrs kit, new valves
2. Radiator serviced
3. New temp sender
4. New fan clutch
5. New heater hoses
6. Water pump striped checked and put back together
7. New theromstat
8. New air cleaner
9. New plugs and Leads
10. New coolant
11. New radiator cap

the temp gauge in the dash is the only thing that i can think of that hasnt been changed and a tune done. and im still getting the gauge showing up to 7/8's of the range of the gauge. it never goes above H into the red zone and im not using coolant and its not boiling into the overflow tank, i am doing an oil and filter change and de sludge on the weekend to see if this helps then a tune for the LPG asap then im flat out of ideas the mech said if it comes to it we may need to put a bigger radiator into it but i dont see it helping if everything else has been done and it use to run fine up until 7-8 weeks ago. have i missed something???

PJHarps
25th November 2012, 10:29 PM
Ok so i have solved the overheating on my patrol. after all the items changed above i took my car to a radiator specialist recommended to me by a trusted friend, he striped the radiator down and informed me that it was corroded and there was signs of separation (he showed me and it was clear there was separation and leakage) he then drove the car putting it under load with ECUtalk hooked up and infra red sensors attached to check the temps. the gauge was showing 3/4's temp but the ecu and sensors were showing 91 degrees when i got the car home i opened the bonnet and noticed the motor was running much cooler with the new radiator and had a noticeable pick up in power/response and fuel economy improved. i thought that the temp sender i had replaced was for the gauge and ecu but was informed by the radiator guy that there was another for the gauge i replaced this and bam the car is reading the right temp on the gauge and running better them ever.

PJHarps
25th November 2012, 10:33 PM
i the 2 pictures above are the 2 senders

the green being the sender for the ECU
and red for the gauge.

ECU sender: genuine -$100, aftermarket-$30
Gauge sender: genuine-$65 aftermarket-$20

i went aftermarket for both and they both seem to be working right. i suggest if you have a TB45 tha'ts overheating try changing them first or at least the gauge 1 to see if it reads right after. my head was buggered anyway so it wasnt wasted cash doing it just a pain that 1 little thing hid all the way to the end to find.

lorrieandjas
26th November 2012, 01:05 AM
Glad you got it sorted mate.