Fixing my Hilux's 7M-GE engine

[BenHur]

I had my head skimmed for the second time due to sloppy work that was done by the workshop who replaced the Head Gasket the first time after my accident last year in September. It now looks like either the head was not skimmed properly or the head was not torqued properly since the HG blew again after 6 months (less the 15000 kms).

My first idea was to simply replace the engine altogether as you can buy them complete for between R 4200 - R 5500. But I also want to improve on my conversion after all the lessons I learned from the 1st time around. So this project was placed on the back burner for a while as I have too many other balls I must juggle simultaneously.

In the meanwhile my Father In-Law mentioned to me the other day that he sends about 5-10 heads a month in to a particular engineering shop since they deliver such good work for him. So I asked him if he can wangle a free compression test on the head to determine the extent of the damage. He agreed and I delivered the head to him on Monday evening. He phoned me on Tuesday evening saying that my head is back, they tested it and it is not cracked anywhere and they sommer skimmed it for me free of charge as well.

I am now investigating what head gasket to use. I found a few articles on my PC that I saved long ago (got some from friends and downloaded some from the net).

HKS METAL HEAD GASKETS, ENGINE PREPARATION & MACHINE WORK.pdf

(126.68 KiB) Downloaded 93 times

This one particular deals with the use of metal head gaskets. It is from the Supra Owners Network in Canada (SONiC) and is very detailed. but after reading this I am not so sure I wan to use a metal HG any longer as it seems that they work very well but that both the head and the block must be prepared properly to a "polished" finish. Considering that this is an old engine that has been machined before and I am not doing any work to the block ( I see this as a cheep fix until I can buy another engine), I think a fibre gasket would be a better choice for me just as long as I torque the head bolts to the higher value as discussed in the other topic about the 7M-G(T)E engine conversions. (viewtopic.php?f=1&p=6249#p6249) Is my thinking correct or am I missing the point here?

Now here comes the big question. If I go the fibre gasket route, do I buy a Toyota Head Gasket or will a Payen gasket be sufficient, or can anyone recommend something else? I would prefer to have the option of getting a thicker gasket to keep the compression ratio of my engine closer to stock as I already struggle with a pinging engine.

[DOELLOOS]

Hi Bennie,

I have posted this on another thread, but I would recommend speaking to Danie from Supratech. He is based in East-Lynne, and knows these engines inside and out like the back of his hand. He doesn't charge for good advice, and doesn't charge a lot when he has to do work for you. His number is 083 990 9400.

Why would you want to replace your engine? The blocks on these engines are almost atomic bomb proof...

[BenHur]

Because it would be cheaper to buy another one then to do a proper overhaul on the current one.

If I buy a now one again I will have them test it properly first and then remove the Head at their place to check the state of the HG. If is is still OK I will then take the engine and just replace the HG and be sure that I have a solid motor. I have seen threads where guys were removing some of these engines out of running cars with low mileage just to remove the head and see that the HG was on its way out already.

[DOELLOOS]

Howzit Bennie,

Won't it be cheaper to get a new engine now, instead of going to the trouble of fixing the old one, and then getting a new engine anyway? I think Supratech does have a 7M-GE in stock for a very good price...

[Family_Dog]

Reading through this thread and the one Ewald posted earlier in another thread, I am beginning (albeit somewhat reluctantly at first, but slowly coming round to accepting the idea...!) to take an active interest.

What is the sense of me preparing to dish out ±R4k to install an EFI conversion to my 4Y, when for about the same price I can buy a whole Cressida engine. I have always been anti these major conversion because of the related problems that mnay people seem to have picked up from them, but would I specifically need an EFI/ECU 7M-GE engine? Isn't there a carurettor version available, and if so, then I probably won't need an ECU at all?

So I would require a larger radiator, could I still use the standard gearbox etc? Is this a factor worth considering?


-F_D

[BenHur]

Eric

Simon's friend with the white one he showed on here before runs a 7M-G with a carb jobbie.
viewtopic.php?f=14&t=161&p=790&hilit=7mg%2A#p790
But fitting a 7M-G(minus the E :)) motor with out the EFI is going backyards in my books. Your bigger problem on these engines is to rather to make sure you sort out the HG before it becomes a problem.

(BTW, 7M stands for 7th Generation of the M (Staight 6) family of engines.
GTE stands for:
G = Performance wide-angle DOHC
T=Turbocharged
E=Electronic Fuel injection

So an engine like Simon’s friend should be called a 7MG engine)

Most people would be very happy with the 7M-G(T)E running on Dicktator. If it was dyno tuned properly the first time round including the cold staring mappings you should not have to karring with the ECU mapping again, except if you karring with the engine to optimise it more.

I had my Mr Turbo mapped properly the first time round and afterwards only corrected small things here and there as I continued with the modification, i.e. when I installed the extra idle ups for the aircon etc. (which should not be a problem with Dicktator which does proper idle control Unlike the Mr Turbo).

The reason why I am still looking at other systems is an inherent flaw in my own software algorithms. Long ago when I was still a technical specialist, before going into sales, part of my job was to take new software/hardware systems from our suppliers into a lab to see if I could "break it". My job was to find (even if it was the tiniest) flaws in the code, to document it and send it back to the suppliers to fix before it was released as a product to our customers. Thus, I am very anal about things like this. If there is a feature that is not working correctly, even if it is commonly not used, like me and the Knock sensor on these ECU's I would karring until I can get it to work.. I have spoken to many guys who is happy with the Dictator, and I might settle for it as well but if I can get a system that will allow me to use the knock sensor as well then I would be happier. Even if it will add little benefit other then personal satisfaction.


If you revert to a carb the problems that you want to avoid here will even be worse, since then you will have to revert to a low-tech electronic ignition system, which will also not be able to incorporate the knock sensor. Your only choice might be a Spitronic ignition system, since the “all-in-one-box-electronic-ignition” dizzy on your 4Y will unfortunately not work on a 6-cylinder engine. Then you might be stuck at where Zantus is now. His problem is most probably not with fuel but with the ignition part of his system, and the fact that it does not integrate intelligently with the EFI to correct the timing according to the engines’ throttle position/air flow.

[BenHur]

Howzit Bennie,

Won't it be cheaper to get a new engine now, instead of going to the trouble of fixing the old one, and then getting a new engine anyway? I think Supratech does have a 7M-GE in stock for a very good price...

Well if all goes well my repair bill would be the cost of a head gasket ( and some o-rings for the injectors since I see the current ones it becoming FUBAR, ( BTW I always thought it was a local slang word but according to http://dictionary.reference.com/browse/fubar it is a WWII military slang word - see explanations at the bottom half ) and sundries like oil, filter, antifreeze etc.

Besides, I might just decide to install this engine into

when I buy a new engine for

[ToyX4]

Bennie, verskoon my amper off topic dom vraag.

Maar hoekom kry mens nie die oorspronklike ECU saam met die enjins (Lex V8 en 7MGTE's) nie?
Verstaan ek reg as ek se dit is die probleem, dat daar nie n oorspronklike ECU is nie, daarom moet julle Dicktator of Spitronics of so iets gebruik?

[BenHur]

Ja hierdie enjins kom uit die ooste waar 'n kar as hy 'n sekere afstand afgelê het(+-80 000km) of as hy effe gestamp word, summier "gescrap" word. De ouens maak dan die engines los, knip alle drade en pype stomp af, pak die engine in 'n krat en stuur dit hiena toe. Die engines is volledig behalwe vir die radiator, Mass Airflow Sensor en die res van die harnas wat die ECU, ignitor en Coil bevat.

Ek het 'n ECU gekry maar kort nog 'n MAF sensor. Die probleem is dat 'n MAF sensor teen > R5K kos teenoor 'n aftermarket systeem van <R3K.

[ToyX4]

Ek het 'n ECU gekry maar kort nog 'n MAF sensor. Die probleem is dat 'n MAF sensor teen > R5K kos teenoor 'n aftermarket systeem van <R3K.

O.K. Maar is dit dan nie n geval van goedkoop koop is duur koop nie?
Sal die MAF sensor jou probleme uitstryk? As dit die geval is sal ek dan eerder die ekstra velle uithaal. Maar dis net as dit die probleem sal oplos. Maar ek mis seker iets. Weet niks van die goete af nie. Julle manne ken julle goete

[BenHur]

Nee daar is meer goeters om in ag te neem.

Die bedrading op die oorspronklike sisteem is ook baie meer kompleks en 'n jan alleman kan nie toegang tot die ECU se program kry nie, net Toyota self. Dus moet jy nog verdere onkoste aangaan om 'n piggy bag chip (soos die dastek unichip) te kry as jy die engine wil optimiseer.

Die rede hoekom iemand soos ek so 'n projek aanpak is oordat dit 'n hobby is en lekker is om te speel en die systeem beter te kry. So ek verkies 'n stelsel wat ek self aan kan karring en optimiseer.

Een van die verdere "benefits" van 'n stelsel soos Dicktator is dat sy "advanced" idle control kan gebruik word om in die veld mee te ry. Die rekenaar sal probeer om engine spoed te reguleer tot omtrent 1500RPM. My plan is om die stelsel op die volgende manier te laat werk: Sê nou ek wil 'n steil bult uitklim kan ek die idle spoed opstoot na sê 1200 RPMs. Soos wat die las op die engine meer word sal die rekenaar probeer om die engine spoed konstant te hou deur die Idle Contol valve meer oop te maak, amper soos 'n lae spoed cruise control. Met die oorspronklile ECU is dit nie moontlik nie.

[ToyX4]

Jy sien. Daar leer ek iets.

Dit wat jy vir my se is net logies. So nou verstaan ek dit beter!

[BenHur]

Is almal vas aan die slaap hier?

[ToyX4]

Is almal vas aan die slaap hier?

Hoekom :?

[ToyX4]

Quote:
Is almal vas aan die slaap hier?


Hoekom

Scratch dit! Ek hou baie van die groen Bennie :!:

[BenHur]

Uiteindelik

[DOELLOOS]

Hoesit Bennie

After searching far and wide, I found this nice link for you.

http://toyota.replacementparts.org/toyo ... ement.html

Hope it's cheap enough...

[SYRON CONVERSIONS]

Bennie concerning the type or brand name gasket to use, well Payen is an excellent product to use, a few years back, I used to own a Saab 99 motorcar, it was a 1973 model, I had to fit a new head gasket as well, it had a TR7 engine which is half of a Stag V8 TR7 engine, so what I did was make a tempelate of the cylinder head, measured what the thickness of the gasket must be and they made up two gaskets for me and then even gave me the hard tempelate mound to use for future gaskets, thus in your case, I would contact them and get them to make a gasket for your engine that is the correct thickness, you will have to measure the length of the head bolts as well and check their stretch limit and what they are at now.

Take a straight edge, check the block surface and see that it is level, if you see any gaps under the edge, then you will have to have the block machined as well and the piston heads tops skimmed.

Will chat again

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