Some of you that visited the old chatroom a while back or scoured some of my posts may have noted that my TR was out of action, being down in compression in one cylinder. It's been determined that the problem is with the valvetrain rather than the piston rings or cylinder head. It's about time I did something about it.

Initially I had intended to replace the heads entirely with a $160 set from the Northern SA U-Pull-It yard. Seemed like a good idea, but it basically means I have to get the heads off, have them resurfaced and serviced (uncertain of price there), then spend the hours removing the old ones and fitting the new ones, plus timing.

I figured if I was going to that extent, I may as well get new parts and replace the valves individually. This would take roughly 9.5 hours provided we knew exactly what we were doing and had all the necessary tools. Overall cost is $160 for 12 ACL valves, not counting gaskets and seals (Valve Regrind Set). Pitfall to this is that we don't have the necessary tools nor skill with Magna engines to take on such a task, and it would cost at least $600 in labour to have them replaced professionally.

Today I had quite the offer though.

A complete donk (long motor), sans alternator, power steering pump, AC compressor and EFI for $320. (those 4 can be added for an extra $225 on top) One would think this is too good to be true, hence why I called them back four times and confirmed it anonymously with different staff. Same response each time. Plus I have up to 16 engines & cars to choose from in the yard, and in his words- "you're bound to find a good one". Probably with lower KM's too.

So i'm leaning toward this option.

Provided we have an engine crane, a decent toolkit, and a few guys helping with a decent knowledge of mechanics (plus actual mechanics should we need them), do you think this is the best option? Or should we still opt for one of the previous options and if so, why?

It sounds like a pointless question since the wording of my post indicates that we've settled on the third option. This isn't true, we could still be swayed either way, and it's probably best to get opinions from real world folk with true experience with Magnas & Veradas than the odd mechanic looking to make a quick buck.

So, floor open to suggestions. Which option would you take, 1, 2 or 3?

The new motor option seems the cheapest and easiest. I have not had experience with engine swaps but I'm prety sure it's an order of magnitude below rebuilding the valve train and all that surfacing etc that has to be done.

Seems the simplest option.

Make an interesting project thread if you do go ahead with it.

I am going to say motor, but check some things out about it first.

1. Sump pick up, make sure it's not blocked at all, oil starvation kills motors, trust me :(
2. take of the rocker cover, everything under there be clean and the rollers/cam should be free of pits
3. take of the little timing chain check cover, try get one with a chain that looks reasonably new and doesn't have much play
4. Water pumps are cheap and easy to replace, not a problem at all if it's rooted

1. Sump pick up, make sure it's not blocked at all, oil starvation kills motors, trust me :(

2. take of the rocker cover, everything under there be clean and the rollers/cam should be free of pits

Good point, i'll most certainly check those two.



3. take of the little timing chain check cover, try get one with a chain that looks reasonably new and doesn't have much play

Since the 6G72 has a timing belt, I shouldn't need to check any chains. Unless it's some kind of Cyclone-Astron Hybrid... I shudder at the thought. (Sorry Astron guys, It's a good motor but I wouldn't own one again. Ever.)


4. Water pumps are cheap and easy to replace, not a problem at all if it's rooted

I'll change the water pump while i'm putting the engine in, along with a new radiator and a full cooling system service. Timing components will get replaced too just for peace of mind. Can't forget basic gasket changes either.


So it looks so far like replacing the donk is the best option. Lower KM components for a fraction of the cost of a valvetrain overhaul + gasket set + labour charge. The only thing i'd be concerned about is connecting it up with the gearbox... never done that before. Probably should get a mechanic to supervise that part of the job.

I dont like the idea of ripping another motor out.
Why? Because these are prone to having the VSS going, meaning you might find a dud. actually a very good chance of doing it.
To get a head machined I think is about the $40 area.
Does your mate know these motors? and does he know how to do heads?
To get the heads put on and taken off is about $300. I would take them off yourself if you can, making sure you put every set of bolts on its own zip lock bag with what it is on it, and take them to get fixed.

I did this with mine but I purchased re-co heads at about $650 (around that price) and the VRS was another $150.
You know your going to have a good engine at the end of it.

I just don't like your chances of finding another motor in good condition, It's only going to need work done to it to bring it up to par.

or worse comes to worse mate, just get the front head rebuilt. Do your water pump while your at it too. That way, you have an engine you know the ins and outs of, not an engine that you have NFI about and could be screwed anyway

edit** also saves you having to do the gearbox + engine mating, thats more money there!

I suppose it wouldn't hurt to take the heads off the current motor and check the condition of it, the top end and bottom end are still in fairly unknown condition on the current one.

My mate is a mechanic, fairly familiar with the 3.0L SOHC 6G72's and says they're "fairly easy" to work with. The other mates, on the other hand, are very familiar with cars in general rather than a specific make and know more about tasks such as engine lifting and installing.

The *only* reason I considered swapping the motor is because at least half of these engines are known working. The only major concern I would have is with Valve Stem Seals, Sump Gaskets, Rocker Cover Gaskets and Water Pumps, which should be changed over anyway.

However, some great points made there. Exactly some of the Pros/Cons input I was after. Cheers. :)

I suppose it wouldn't hurt to take the heads off the current motor and check the condition of it, the top end and bottom end are still in fairly unknown condition on the current one.

My mate is a mechanic, fairly familiar with the 3.0L SOHC 6G72's and says they're "fairly easy" to work with. The other mates, on the other hand, are very familiar with cars in general rather than a specific make and know more about tasks such as engine lifting and installing.

The *only* reason I considered swapping the motor is because at least half of these engines are known working. The only major concern I would have is with Valve Stem Seals, Sump Gaskets, Rocker Cover Gaskets and Water Pumps, which should be changed over anyway.

However, some great points made there. Exactly some of the Pros/Cons input I was after. Cheers. :)
That's cool. I still think if you know your motor is in good/great nick, or know the downfalls of it, do the heads IMO. or as I said before "head" When I did mine it was a GIANT learning curve for me. i.e. drain all coolant out before taking off lower intake manifold:bowrofl: or else it just fills up 6 cyl's with coolant....So I learnt alot but car was off the road longer then expected.
Expect to be forking out at least $500++ for this project.
Can I please suggest at least getting the intake manifold and rocker covers powdercoated or something :P we need a nice looking SOHC 72' on here!!

A tip - If you do plan on pulling the heads, go to u-pull-it, or whatever your local self serve wrecker is, and take one apart. just rip it all apart so you know how this stuff works. i would of loved the opportunity to do this prior to doing my head's would of been some really good experience.

make sure you have a good 1/2" set of tools and you'll need i think a 12mm Hex bit adaptor for the head bolts.

then again, if you took some heads off at the wreckers, and got them fixed up, i.e. new VSS's put in and machined, you could just swap them over in a good days work.
You have alot of thinking to do my friend. If i knew more my car would not of taken so long to get on the road again.

Some great advice and pointers there. I'll agree- it's quite a major learning curve... i've danced with the 4G54 before and lived to tell the tale... shame the Astron didn't. Although that wasn't my fault. Regardless, the 6G72 is a very different engine and i'm certain i'll find some hurdles along the way.

I'm budgeting $500+ to the project, since the car itself cost me $500 I can technically come in at a reasonable price even if i spend $1000 on the motor ($1500 for a TR V6 isn't too bad).



']Can I please suggest at least getting the intake manifold and rocker covers powdercoated or something :P we need a nice looking SOHC 72' on here!!

I've got some plans in that area which I hopefully intend to do before mid year, one of which i've been meaning to look into is Powder Coating.

Can't rebuild/restore/"do up" a car and not give it a bit of shine, right?

It's been a bit of a goal to build the car up to a certain colour scheme, while keeping it subtle and clean at the same time. On top of that, of course every great project has to have highlights, some flare to make it different from everyone else's- good example being your Evo wing. I'm still not sure what to do with this one, but I want it to be noticeable or noteworthy.



A tip - If you do plan on pulling the heads, go to u-pull-it, or whatever your local self serve wrecker is, and take one apart. just rip it all apart so you know how this stuff works. i would of loved the opportunity to do this prior to doing my head's would of been some really good experience.

Just so happens that U-Pull-It is the place selling the complete engines, so i'll have to swing by there at some point anyway. I'll take off a cylinder head or two to get a feel for it while i'm there- probably end up walking out with just those heads.



then again, if you took some heads off at the wreckers, and got them fixed up, i.e. new VSS's put in and machined, you could just swap them over in a good days work.
You have alot of thinking to do my friend. If i knew more my car would not of taken so long to get on the road again.

That's probably a decent idea. I'd much rather get two good, working heads then tackle it all down over a weekend rather than remove the existing ones, send them off for 1/2 weeks (or service them myself in that time), get them back and forget everything I learned during the disassembly weeks earlier. Plus if I made a mistake taking the wreckers heads off, it's no big loss.


Alright well, I think i've got enough info, i'll make a trip to the wreckers and have a bit of a wander around. Regardless of whether I walk out with 2 heads or a complete motor (plus a barrow-full of relays and fuses) it'll at least get that car running again. I'll need to suss out the condition of my motor, their motors and their cylinder heads before I can reach a definite verdict.

Oh my bad, thought we were talking about astrons for some reason....

Just a quick update, went down to have a look at the car today and made some observations...

Obviously the paint is beginning to give out toward the rear quarter panels with the boot/bonnet/roof fine, and there's some damage to the rear passenger side door where it's been sideswiped (simple, just swap the door). So i'm not worrying about cosmetics, this can all be taken care of.

Electrical wise, it needs some work under the dash. The aftermarket stereo it was fitted with prior to purchase was removed, but they've cut all the wiring as far back as possible- right up against the main wiring loom. :rant: Just as well I can do auto electrical, or i'd be pretty pissed right now. Ignoring the stereo, the rest of the electrical system is in great shape.

Anyway, we were unable to make any progress with the motor. Couple of my mates had a look at it as well and were fairly well puzzled about where to begin and where to go from there. Simplest solution is to get in contact with one of the mechanics about booking it in for repairs, in which case it'll be getting a head recondition rather than an engine swap. I'd like to do it myself and learn a thing or two, but I need this car back on the road and don't have enough time to do so.


I have to admit though... move around to the drivers side though and this is one sexy car side on. Nice and low, just the way it should be. Just needs some TLC. Possibly a wash to remove the inch or so of dirt sitting on it. Then it'll be niiiice. :cool: