Dropping the Pistons on the 4y

[Stubs2]

Hi there, I have a 89 D/cab 2.2 petrol 4y, I am busy replacing the head and am concerned that on the replacement of the head which is new the improved combustion might have an additional strain on the rings if they are worn, I have never replaced them since I have had the vehicle, ( 4 years) so my question is can the pistons be dropped from beneath on removal of sump cover and crank so that I can inspect and replace the rings etc - am not the greatest mechanic in the world but everyone has to start somewhere

[Family_Dog]

Hi Stuart, welcome to the forum.

I have moved your question to the "Technical" section, your chances of getting a reply here are better than in the previous thread topic.


-F_D

[Hoppy]

It's easy to remove the sump and pistons in place as there is no x-member in the way, give it a light hone and make sure the rings is the right size, measure the gap with a feeler guage.

[Mr_B]

Hi Stubs,

You can take Hoppy's word, he works on my '87 4Y when needed, and is the most knowledgable guy I know on the Hilux!

Snipes

[Stubs2]

Hey thanks guys, cleaned up the block head last night ready for the head tomorrow morning, I am gonna ask another stupid question probably - you have all heard of " what you should do is " well I have had several suggestions on what to do when replacing the head and the new gasket from copper spray to painting the block and head with heat resistant aluminium paint !!! WHAT is the really and only best way to replace it, I would of thought just clean as is with no grease, dust or crap on either surface.... any help please. Would I be correct in saying that the torque should be 90nm ?

[Hoppy]

If you use a good quality gasket, it will have its own adhesive(it feels sticky), then you won't use anny other stuff. If it's a steel, or another "smooth" surface type, you can use copper gasket spray or silver paint.
I prefer to use OE, elring or payen gaskets.

[SYRON CONVERSIONS]

Also look out if there is a ridge near the top of each bore, if there is and you fit new rings, the new rings will break, thus if there is a ridge, you will have to have it cut away (this can be done in place).

Fit a new oil pump as well.
Payen gaskets are fine to use.
Not sure of the torque will look in my other book tomorrow.

[Stubs2]

on further inspection and testing the block with a piece of glass and cook spray there is a small indentation on the block by the back cylinder . Can the block be skimmed in place or does the whole engine/sub assembly have to come out !!

[SYRON CONVERSIONS]

come out an do a proper job or buy a chienease import, speak to family dog here

[Stubs2]

having inspected further on the sub assembly it looks like that the bearings were on there way out and the pistons had some slap on them as there was some damage. I have decided to buy a new sub assembly. On a seperate note I have now found or I think that my Air con unit is buggered, on taking the hoses off for starters there was no gas leakage, secondly the clutch unit at the front makes a dreadful noise when you spin it, so obviously the bearing has gone, I also heard someone say that on the older hilux's that the aircon unit used a gas that is no longer available or allowed in south africa - not sure how true this is, can the unit be repaired or is it better to buy a secondhand and/or new part if you can get one - any suggestions on sourcing a new one would be welcomed

cheers
Stubs

[SYRON CONVERSIONS]

Get a new part, do not waste money on 2nd hand parts.

[BenHur]

A reputable aircon place can recondition your pump. They can also modify your system to work on the new gas. All it entails is adding a different valve to the system as the valve they used to gas the system previously does not look the same as the new types. By adding this valve the system should then be able to be filled via either the old or the new gas type filling equipment

[Hoppy]

Have the block skimmed and rebored, use good quality parts, reprofile the cam to brospeed spec and give the head a light flow job, add a branch and a freeflow to complete the package.
Please stay away from chinese import motors.

[SYRON CONVERSIONS]

Please stay away from chinese import motors


Please share your secrets with us all concerning these imports.

What you stated above with his engine is what my engine has had done, it is one awesome piece of machinery.

[Stubs2]

many thanks for all the tips, got me a bit concerned now about a new sub assembly, therefore seeing as you guys have the experience I am going to err on the side of caution and have the original block skimmed and re-bored. As for the cam to brospeed spec this is now getting bit complex for a laymen such as myself so any tips on where to get that done would help (or what you are actually talking about ! ha, ha) , I already have a freeflow branch fitted so thats cool, getting the head lightly flowed I understand. Will I need to replace the pistons or can they also be reconditioned, I will replace the bearings obviously and check the crank out. Am busy getting the Aircon unit checked out to see whats going on. Will drop some pictures in tomorrow so you can see what I am busy with !

[SYRON CONVERSIONS]

Fit new pistons, rings, thrusts bearings (check end float on crankshaft) waterpump, oil pump, Payen Gasket set, maine and big end bearings, clean block correctly before assembly, you can also balance the crank shaft.

Do it the correct way the first time, no loose ends.

[Stubs2]

can the new head be gas flowed and the cam re set without the rest of the engine ? trying to get away without having to tow the vehicle anywhere which is expensive ! - then dyno tune it once I have it all back together and running again !

[Family_Dog]

Have the block skimmed and rebored, use good quality parts, reprofile the cam to brospeed spec and give the head a light flow job, add a branch and a freeflow to complete the package.
Please stay away from chinese import motors.

Hi Allan,

I was interested in your post above. Last January, I posted the question whether to buy a new Chinese engine, or do up the old 4Y motor. Most of the answers I got were favourable towards a new Chinese motor, with several people stating that they were running these motors now and had in excess of 200,000Kms on them without any problems.

The fact that my Hilux has a Branch Exhaust with a Brospeed Chrome end cap on the end of the exhaust, eventually decided me. I do not know whether the engine had been modified for Brospeed or not, but I was worried that it had been done, and I've never heard any thing good about the Brospeed modification for off-road usage. So I opted for the new Chinese engine, although I have since also had the old engine completely overhauled again.

Why do you not recommend the Chinese engines, and why do you recommend the Brospeed conversion?


-F_D

[SYRON CONVERSIONS]

Are you intending to put this engine back together yourself?

If you skim the block, you will have to measure the piston prutrusion and then will have to machine the tops of the pistons off, there are many factors to consider when overhauling an engine.

[Hoppy]

We've fitted the first of these motors about 4 to 5 years ago when they started to import them, it seemed like a good idea at the time, the first to give problems was the carbs, the distributors went next, followed by hydraulic lifters, oil leaks, burnt valves, clutch centres breaking and high oil consumption. I've fitted and worked on at least 40 of these motors and they are definately not the same quality as the original 4y, the casting on the cylinder heads are also to thin to be ported.
I know there are a few different chinese 4y's on the market, apparently some are better than others.
Our taxi guys know these motors very well, i advertise secondhand ones that i remove when i do conversions for about R6500.00, wich is more expensive than new chinese ones,but they sell within 24 ours and the first thing they ask when they phone; "is it Toyota or China"

[Cookie Monster]

HI Allan

Quick question the 4y fitted to ther CAM inyathi van have you had any experiance with the engine as it is also a china motor with fuel injection. I know a taxi operator with a few vans like this with very high milage already a few problems but non engine related. Link to the CAM site

http://www.um.co.za/specifications/cam_ ... 2006).aspx


(Link corrected - F_D)

[Hoppy]

No, i have'nt worked on one of those, i hope they are better quality.

[Stubs2]

after much consideration and the different costings involved I have decided to re do my exisiting oiginal 4Y block, I put the block in today for skimming, re boring, plus the crankshaft polished and balanced along with the camshaft sorted out. I will put in new pistons, oil pump plus all necessary bearings, seals etc. I havent had any badluck with the sub assembly, only real faults I a have had over the years are the head gasket twice, timing chain tensioner, so I am going to stick with what I know I think. Once its all cleaned up and re sprayed will look like brand new - I am busy respraying all parts now like timing chain cover, fan, radiator cover, radiator, new hoses, firewall, plus all water pipes checked cleaned and resprayed once again. One thing I didnt realise is that I asked for new welsh plugs and was told mine are brass so dont need to be changed as they dont rust... learn something everyday!.