[Grace]

Hi Viji, Thanks for your words, there is a learning derived in the mistakes we make. Besides I enjoyed this build backwards. Learnt, never to completely trust recommendations on service providers as it may ruin relationships.

Warm Regards

[jyobeb]

Ok then your costs are very acceptable! Of course I remember you! My methods include a very dubious method of cutting and pasting chassis numbers! Not that I am recommending that method here!!

[AVR]

Originally Posted by Sudarshan

5) choice of welding
a) which type of welding will be the best & who can do it (welding methods )
b ) choice of welding machine & material ( type of rods,its quality etc)

In reference to the pictures posted by Jeepster from redmm340's thread:
1) what is the kind of welding that would work best for the additional cross members?
2) What kind of pipe material should be used to make those cross members?

Some more fundamental questions:
1) What would happen to a 540 with old c-section chassis when a significantly more powerful engine is fitted?
2) What additional stresses are exerted on the chassis?
3) What are the weakpoints on the chassis under higher torque engines? 4) Does spot-strengthening suffice or do we need to have a blanket-strengthening approach like Grace has done?

Thanks,
Adi

[Sudarshan]

Originally Posted by AVR

1) what is the kind of welding that would work best for the additional cross members?

I use a simple arc welding transformer ( 1/2 phase ) ranging from 50 to 200 Amps . I use Ador general purpose MS welding rods , Till date its successful , no problems .
I don't have any first hand experience about MIG welding as such so cant comment on that .

What kind of pipe material should be used to make those cross members?

I personally wont choose pipes , I would choose C sections as one can weld from both sides
Also I will choose material from old Jeep / truck chassis rather than the local steel market


for the following I will try my best ( AFAIK & IMHO )

1) What would happen to a 540 with old c-section chassis when a significantly more powerful engine is fitted?

You surely are going to have problems , It depends on how much larger ( weight ) & powerful the engine is then the standard

2) What additional stresses are exerted on the chassis?

cant comment generally ,but the engine 'thrust' side may get more hammered , expect engine mounts & areas near it to budge/ break

3) What are the weak points on the chassis under higher torque engines?

The area would be just around the GB-- specially between the engine mount & the GB cross member

4) Does spot-strengthening suffice or do we need to have a blanket-strengthening approach like Grace has done?

this will depend on the power & weight of the engine & the terrain / duty you need,
I will put a drawing ( My Idea ) for chassis strengthening soon

Sudarshan

[Sudarshan]

Originally Posted by Sudarshan

==
==Also I will choose material from old Jeep / truck chassis rather than the local steel market ===
===I will put a drawing ( My Idea ) for chassis strengthening soon ==

here is my Idea , I would buy an old Jeep chassis ,dismantle it completely ( to each & every piece ) , then I will choose the long members drill some big holes* in it to reduce weight & weld it in CinC fashion** , this long member will look like this




explanation
C in C fashion ** : as follows



explanation
holes* : for a 4" chassis height portion it wont be more than 1.5" dia ,These holes will also provide access for some anti rust painting after welding ( cheap alternative to galvanising ) , A total box will deny that .

Sudarshan

[AVR]

Thanks Sudarshan bhai, this is useful. Strengthening the entire chassis with the c-section addon makes more sense than additional cross members as the positioning of the cross-members may not be optimal given my limited knowledge.

Cheers,
Adi

[Frankenstein]

Originally Posted by Sudarshan

I use a simple arc welding transformer ( 1/2 phase ) ranging from 50 to 200 Amps . I use Ador general purpose MS welding rods , Till date its successful , no problems .
I don't have any first hand experience about MIG welding as such so cant comment on that .



I personally wont choose pipes , I would choose C sections as one can weld from both sides
Also I will choose material from old Jeep / truck chassis rather than the local steel market


for the following I will try my best ( AFAIK & IMHO )

You surely are going to have problems , It depends on how much larger ( weight ) & powerful the engine is then the standard


cant comment generally ,but the engine 'thrust' side may get more hammered , expect engine mounts & areas near it to budge/ break


The area would be just around the GB-- specially between the engine mount & the GB cross member



this will depend on the power & weight of the engine & the terrain / duty you need,
I will put a drawing ( My Idea ) for chassis strengthening soon

Sudarshan

Sudarshan, a few doubts, generally as you know in Jeeps, the area around the engine /tranny is already boxed (in a C section old chassis). The chassis from the middle till the rear is a C section , which is also reinforced by another C section from the inside. If suppose a heavy scorpio or perkins p6 engine is plonked into an old 540 , what part of the chassis will brake .

Will the middle C section part break while the vehicle lands hard?

Will the front box section crack because of the engine weight as you said?

Will the whole chassis twist and break during suspension flex because of the engine weight?

How can we make the front box section stronger?

If we add additional cross members like the cj340 pics posted above , wont the chassis crack because of the lack of flexing.( i was told that it does by local load carrying Jeep drivers who had bad results ).

The diagram posted by you shows the chassis sagging, i guess it is due to load carried by the Jeep (taxis) or is it caused by powerful heavy engines.

[Sudarshan]

Originally Posted by Frankenstein

The chassis from the middle till the rear is a C section , which is also reinforced by another C section from the inside. If suppose a heavy scorpio or perkins p6 engine is plonked into an old 540 , what part of the chassis will brake .

Frank-- forget something like P6 , its way too heavy , but the scorp ? yes its possible .

I will suggest you go through my post # 7 once again . Compare the Jeep & Landy chassis , the main difference is the C & box section .

But another important feature of landy chassis is the ' Two ' Fixed cross members below the GB & bell housing ( engine flywheel & clutch area ) The old Jeep C chassis lacks strength here ,

The sag area I have shown ( in red circle ) is the inherent weakness of the 'C ' type Jeep chassis , because there is no fixed crossmember in there & the chassis also needs some more strength there .

Now with reference to your Q : even if you do all the strengthening by adding another C from inside , you will need to address 'this' particular issue . You will need to add fixed crossmembers bellow the GB & near the front leaf mounting brackets ( just bellow the engine bell housing area ) so that the flex will be controlled effectively .

Will the middle C section part break while the vehicle lands hard?

Yes quite possible , expect this between the GB cross member & the leaf mount bracket . Another area will be the front chassis ' arch ' the area between the two leaf mount brackets .

Will the front box section crack because of the engine weight as you said?

Quite Possible , the thrust side of engine mounting ( RH ) seems more susceptible

Will the whole chassis twist and break during suspension flex because of the engine weight?

Will surely develop stress with time & finally give way

How can we make the front box section stronger?

IMHO adding some thicker & continious C section ( removing the original ) & most importantly adding those 'Two Fixed Crossmembers ' I have mentioned earlier --- but then you will have to remove the GB from inside the vehicle by removing sections of flooring & seats ( Just like the Landrover )

If we add additional cross members like the cj340 pics posted above , wont the chassis crack because of the lack of flexing.( i was told that it does by local load carrying Jeep drivers who had bad results ).

IMHO , all the load gets concentrated bellow the drivers feet here because all the other areas are ' Rigid ' now & this particular area seems the only weak link in ' That ' chassis

The diagram posted by you shows the chassis sagging, i guess it is due to load carried by the Jeep (taxis) or is it caused by powerful heavy engines.

Not exactly , I have seen this happening in Standard Jeeps ( mostly diesels & above 80" wb ) , this is due to bad roads ( shocks ) & years of abuse / stress building up .

I am not an engineer these are general observations ,

IMHO fitting a more powerfull & larger Petrol engine will not give as many problems as any diesel will give , though it will be a gas guzzler .

IMHO , ( WRT larger & powerful engines ) the area just bellow the drivers feet will be the area where all the stresses are going to get concentrated ( engine torque & suspension stress ) till you take care of that particular area , nothing will work correctly -- Also the Engine foundations , Particularly on the thrust side of engine will need special attention while the re build

Sudarshan

[headers]

@4x4, grace and all posters in this thread:

I have a question -

Would not the area of the weld be a weak link on the chassis?

I believe manufacturers know the best in chassis design, strengthening and we should NOT tamper, weld anywhere at anytime on them.

Would like your views?

[AVR]

Originally Posted by headers

@4x4, grace and all posters in this thread:

I have a question -

Would not the area of the weld be a weak link on the chassis?

I believe manufacturers know the best in chassis design, strengthening and we should NOT tamper, weld anywhere at anytime on them.

Would like your views?

Headers, for a stock vehicle setup, the area of the weld or any form of strengthening will not be a weak link because it won't be required as the original chassis design should take care of all flexes/stresses.

A much more powerful/heavier engine would require strengthening as even with the factor of safety taken into account,the chassis may still be a point of failure. Hence strengthening would be required. Unfortunately people like us would have to count on our greater shared or limited individual knowledge while strengthening the chassis (whether extra-C section or cross-members)

The biggest advantage is that if we weld something onto the chassis and it breaks first then we still have the original chassis to fiddle around with next time around

[Sudarshan]

Originally Posted by headers

Would not the area of the weld be a weak link on the chassis?

Not necessarily ; it depends on how the thing is done , I have done this twice --when my 540's chassis gave way & also when I met with an accident . I had no option

But I took care not to add gusset plates & welds to a particular spot . I took care that the load & stress will be spread evenly . All this was done in & before 1997 so 14 years on & almost a 80 K km of mixed driving the thing still holds

I believe manufacturers know the best in chassis design, strengthening and we should NOT tamper, weld anywhere at anytime on them.

but what one can do if a chassis cracks or sags or if some damage is done by accidents ??

More than that-- What if we are putting more powerful engines in it & want a more " Extreme off road duty ' from the same Jeep ??

We dont have much choice WRT the duty we expect . There are only a few engines ,GBs , T cases to play with --- for chassis we actually dont have anything & till we get something , this ' Trial & Error ' will continue

Sudarshan

[headers]

Originally Posted by AVR

The biggest advantage is that if we weld something onto the chassis and it breaks first then we still have the original chassis to fiddle around with next time around

I get what you are saying but nevertheless no chassis welding for me if i can help it!!

Originally Posted by Sudarshan

when I met with an accident . I had no option

But I took care not to add gusset plates & welds to a particular spot

Looks like you did not have much options explored.

Anyways, glad that you guys understand that chassis welding should be restricted - not done unless beyond one's means!

[Sudarshan]

Originally Posted by headers

Looks like you did not have much options explored.

what are they ?? can you explain further ??

This will be really helpful if other Options / alternatives are available !!!

Anyways, glad that you guys understand that chassis welding should be restricted - not done unless beyond one's means!

no one touches the chassis without reason IMHO

Sudarshan

[jeepster]

some pics from my side.

rgds,
Nikhil