Mk1 Supercharger Conversion Engine Mount Strengthening

[DNOS808]

Hi Guys,

I am turning to you all again for some advice/ideas regarding my latest issue with my Mk1 monster. I know for a fact that I could never have got as far as I have with this project without you guys.

I have installed a 4AGZE from a Corolla Levin in my Mk1 and I am wondering about strengthening the front and rear engine mounts since this engine produces a lot more torque than a standard 4AGE. If one or both of the engine mounts let go it could get messy!!

An obvious way to improve the rear mount would be to replace the standard two bolt mount with the Supercharger style four bolt rear mount. Does any one know if this would be enough to take care of the mount ripping out problems that the Levin 4AGZE can produce?

As for the front mounts I assume that people just add some extra plating to the area of the mount.

If anyone knows of any simple ways to beef up the mountings please let me know how it is done.

[kaiowas]

I know Paul advocates beefing up the mounts on 3sgte conversions but I'm not sure it's really done on GZE conversions. Our car runs standard na gearbox and mounts with poly inserts and I've had no trouble with them and I'd say ours takes more abuse than most being a sprint car. It'll be subjected to 10 hard launches on a sprint day (double that when we both drive) on top of the usual loads associated with track use.

[DNOS808]

That is interesting. Sprint use must be brutal on the two engine mounts that control the torque. If your mounts can withstand lots of track and sprint use they cannot be that weak!

[PW@Woodsport]

It's not necessary to beef up the torque mount areas on a 4a-gze swap, they don't produce enough torque to trouble them.

On 3s-gte and V6 swaps these areas must be strengthened, but they produce way more torque very violently and do crack these areas if left stock.

I've found anything over 200 lbs/ft needs reinforcing, below that don't bother, unless your chassis is suspected of being rusty/weak.

[Lauren]

Does any one know if this would be enough to take care of the mount ripping out problems that the Levin 4AGZE can produce?

There aren't any problems with teh engine mounts running a later spec GZE. I did this back in 2001. No problems at all.

[Lauren]

Just to add, mine produced 186bhp/180lb/ft. I did over 30 trackdays in mine with no issues whatsoever.

[PW@Woodsport]

Even on the tuned 3s-gte installs it only ever happens over 300bhp and really hard 1/4 mile launches.... so as a rule we reinforce those areas on anything over 200lbs.ft, below that... not necessary.

[aw11rally]

I've cracked / damaged / torn the front torque mount on a nearly standard 4a-ge powered mk1, a nearly 200bhp N/A mk1 and a tuned 3s-gte mk1.

I'd say strengthen it now to save having to do it at a later date.

I will add that I have zero mechanical sympathy and thoroughly enjoy full rev standing starts, I also advocate the use of aggressive clutch kicking to reduce the AW11s tendency to understeer. What I'm saying is that just because I've broken them doesn't mean you will. do what you feel is right for you.

My method of strengthening is to get hold of a spare front torque mount and cut the flange from it. Bolt the flange to the chassis then weld it to the car as thoroughly as possible, remove the bolts then reassemble the complete torque mount and attach to the gearbox. Be sure to use plenty of thread lock on all the torque mount bolts to both the chassis and gearbox. The last thing you want is them vibrating loose and stripping threads etc.

It's not failed yet, not even with the tuned 3s-gte.

I must add that the nearly standard mk1 had poly torque mount inserts and the nearly 200bhp 4a-ge mk1 had alloy inserts. The increased stiffness in both cases may have contributed to the chassis damage.

[stenky]

just ordered my poly mounts. is it enough to reinforce just the front mount right? i believe the front mount is the one that gets shock-loaded after vigorous launch.

[PW@Woodsport]

This really boils down to what you use the car for, Aw11rally uses his for motorsport, which is an entirely different scenario to a road car, there is zero mechanical sympathy.

On a road car it really is not necessary to beef the torque mount areas, my own 3s-gte Mk1 was not strengthened in those areas but never saw more than road use and lasted years without cracking. If i had competed in the car then yes it would have needed strengtheners.

[DNOS808]

Thanks guys for all of the excellent replies.

My car is only used for road use and I do not drive it that hard. In reality the torque generated by my 4A-GZE is probably not that great on comparison to some of the high powered creations of Paul and you guys who do the sprints etc.

It sounds like it is only the front mount that lets go which is a surprise since Toyota went to the trouble of beefing up the rear mount on the Supercharger. If only one of the mounts is likely to go at once I do not think any failure would be totally catastrophic.

My main worry was a scenario where one mount failed and the other then took all of the torque and also failed. I had visions of the engine flailing around in the engine bay and ripping the wiring loom, fuel pipes etc to pieces!!

I think I will leave the mounts standard and just monitor them to see how they stand up. From what I can gather the mode of failure of the mounts is not too dramatic if they do go and there is a good chance the mounts will be up to the job as they are.

[AW11mike]

Hi stenky, where did you order your poly mounts from? thanks,Mike

[stenky]

speed-source. their shipping selector is broken and so only the most expensive shipping methods can be selected, so I had to do it via virtual address provider

[AW11mike]

Thanks.

[SuperRedMR2]

Hey mike i'm interested in these as well - if I email em shall I see if we can get a discount?

[AW11mike]

Sounds good Alex!

[kaiowas]

I know Paul advocates beefing up the mounts on 3sgte conversions but I'm not sure it's really done on GZE conversions. Our car runs standard na gearbox and mounts with poly inserts and I've had no trouble with them and I'd say ours takes more abuse than most being a sprint car. It'll be subjected to 10 hard launches on a sprint day (double that when we both drive) on top of the usual loads associated with track use.

I'm now a fully paid up member of the mk1 serial abusers club. After 7.5 years of sprinting, 6.5 of those with a GZE and 2 events with the 6 speed gearbox I ripped out the front engine mount over the weekend

By the time I found out what the odd banging noises were the front bolt was mostly wound out, the rear bolt was missing and the captive nut was rattling around inside the mount. With the remaining bolt tightened up again I still finished the event OK although I did need to retighten it by about 1/12 of a turn after every run. Need to attack it with some steel plate and a welder now.

[PW@Woodsport]

I think Mk1's are inherently weak in those front and rear torque mount areas, it's just with an NA or GZE motor it takes a lot of abuse before it cracks, the 3s-gte and V6 swaps destroy those areas pretty quickly if left unstrengthened.

Stick a 6" square speader plate on the front mount chassis area with some captive nuts welded to the back of the plate, cut out Toyotas original nuts and it will never fail again.