Thread: Cams, lifters, timing chains sprockets

My multiple question is:

A, How big is the job to replace the lot.

Depends what you mean - either way you are looking at pulling out the donk, have it mounted on an engine stand so you can rotate it anyway you want, my 3.5 after 280k was actually pretty good including he cam. But yeah - if you are pulling it, means sorting the FI, all the plumbing - From my personal experience - give her to someone to do for you.

B, Car is a daily driver and occasional tow vechile, is there any benefit (fuel economy wise) in installing a 'better than standard' cam?
Would be better putting in a 4.0 or 4.6lt, other wise I'd say no

C, Timing sprockets with nylon teeth, or the Rollmaster induction hardened sprockets (JP performance). Any comments or experiences good and bad with these?
When I replaced mine I went with the stock option - why not after all - if they lasted 220k fine - why upgrade them

Is there any way the cam can be done in the car?
Remove grill radiator etc...?

I'm thinking that pulling the engine out is way to big a job, especially since I just got the air con regassed and working!

Camshaft removal in the vehicle will need the a/c condensor removed, so a re-gas. Removing the engine shouldn't require a regas as you should be able to swing the compressor away.

I would first check the backlash of the timing chain, replace that with an original type. If you aren't thrashing the vehicle even a slightly worn cam won't affect it much. Certainly it won't cause the vehicle to stop embarrassingly at any time. I would leave the cam until there are more issues like rings, bearings heads etc requiring a full tear down.

BTW cam wear is very dependent on oil type and change frequency. I have seen a 600K cam (XF Falcon taxi) look far far less worn than a 300K cam because of the use of Penrite oil changed regularly.

The car doesn't have a hard life at all so yes, leveler heads are begining to prevail. Standard chain and sprockets seems to be the way to go for now and worry about a cam later on if needs be.

Next question, do all standard sets use the nylon toothed gears? and are they the best option for standard?

I've replaced many standard timing chains without changing the gears, they rarely give trouble on the first chain swap. Just my opinion, mind you, change everything if it makes you feel better.

"change everything if it makes you feel better."

Very diplomatic of you Beeutey, thank you

BTW I did your bosch ignition module upgrade a couple of weeks ago along with a new vacuum advance unit and it is a different car on petrol!

I still haven't managed to get my injected gas to run 'properly' yet though.
It is on of the marrelli kits from the UK. Have done the auto tune feature and also mucked about endlessly with manual corrections to the multiplier line along the injector curve but it is still missing and very sluggish until higher revs.
I have advanced the timing as far as the dissy will go (the timing light is in an unmarked removalist box amongst 30 or 40 other similar boxes!) and it just feels like perhaps it needs to go some more. This is what got me thinking about stretched timing chains etc. Perhaps as a test I could advance the dissy by a tooth and readjust (by ear for now).

What thinkest you?

Originally Posted by Richard93Vogue

"change everything if it makes you feel better."

Very diplomatic of you Beeutey, thank you

BTW I did your bosch ignition module upgrade a couple of weeks ago along with a new vacuum advance unit and it is a different car on petrol!

I still haven't managed to get my injected gas to run 'properly' yet though.
It is on of the marrelli kits from the UK. Have done the auto tune feature and also mucked about endlessly with manual corrections to the multiplier line along the injector curve but it is still missing and very sluggish until higher revs.
I have advanced the timing as far as the dissy will go (the timing light is in an unmarked removalist box amongst 30 or 40 other similar boxes!) and it just feels like perhaps it needs to go some more. This is what got me thinking about stretched timing chains etc. Perhaps as a test I could advance the dissy by a tooth and readjust (by ear for now).

What thinkest you?

Ask someone in your neighbourhood for a loan of a timing light, there's no substitute. Petrol will run fine where gas needs 5 degrees more advance.

As for the LPG, do you have an oxygen sensor installed? If you had you could see where the mixtures are wrong. I have done two injection installs on non-cat Toyotas and wouldn't have been able to tune them properly without an O2 sensor for reference. It doesn't adapt to the ECU, just sits there for the readout on the LPG tuning screen.

Yes I have got 2 brand new oxy sensors ready to retro fit...have had them for a few months now. I just have to find the time to install them. Looks like that will become a priority now.

I will source a timing light too and do it properly.

Thanks for your advice.

Richard.