Seam welding RA28

[Toy77]

G'day Guys n Gals,

i am at that point of the engine conversion where it is time to tidy up the engine bay. i am looking at seam welding the bay.
Some questions -
what is the best way to actually do it?

Am i better off seam welding or stich welding?

how much stronger (less flex) will it make it?

what areas need to be done?

What are the downsides if any?

Cheers
Stew

[Rodger]

Stew,

Depends on what the finish you want.

Strength? Or good looks? Or strength and good looks.

Four options:

1. Weld completly and grind off to smooth out and bog and fill for a smooth look. The best way to guarantee the finish. Most time and resource consuming.

2. Weld each seam 50% (the method of stitching) , grind and bog. Will give good finish and can last as long.

3. Weld 50% paint and finish. This is the quickest method and does look good and is the prefered method of adding the desired strength.

4. Bog and finish all the seams and excess holes and paint. Easiest way to get a smooth engine bay. Good for a few shows but with time and body flex the seams start to open up and pop bog out. As is now happening with my old Show '22.

Regards

Rodger

[Toy77]

hi,

chasing strength and finish.

the 1j should be putting out around 300rwkw and launching on sticky tyres is gunna give the 30 year old body a real hard time.

as for the finish - have a look at my members rides thread - i have spent a small (or large depending on your view) fortune getting the rest of the car up to the desired level (quite high in my opinion) and i want the engine bay to match.

Thankyou fo ryour input
Stew

[Rodger]

The next step for me, now that I am using my '22 for track days is to reduce some of the flex by adding in a triangulated strut brace.

I wish now that I had done the welding, but I suppose at the time it was to be a show car.

Perfect opportunity then for you to do both.

Regards

Rodger

[Toy77]

yeah, i plan on triangulating my strut brace back to the fire wall too.

Cheers
Stew

[YLD-16L]

You may or may not need to have you car put on a chassis aligner after the seam welding, as depending on how you go about doing the welding there will be some distortion taking place.

Just do small sections at a time and alternate from one side of the car to the other as you go to minimise any distortion that will take place.

[Joshstix]

The advantage of stitch welding over seam welding, especially if it's going to be ground and filled then painted, is that if you get a crack it will only spread to the end of the stitch weld instead of all the way to the end of the seam weld.

As to the downsides as pointed out the heat will most likely cause some distortion of the metal work. More importantly though I think for a car like an RA28, making the front end stiffer is just going to transfer all the stresses to the next weakest location and the cabin area of an RA28 is far from solid in my opinion.

[Toy77]

points noted thanks guys,

what other recomendations would u have for stiffening her up?

i am already planning a bond bolt in half cage and a rear strut brace.

cheers
stew

[Toy77]

hey,

i spose i should also point out that the guy doing the welding in the engine bay (and the rest of the bay) is one of the panel beater who did the rest of the body on the car so as far as welding and disortion goes, he should be very competent.

Thanks, keep the advice coming

[YLD-16L]

Have a look at what TwinTurboCelica has done to his 1J RA28 for ideas as that thing has seen a lot of track time and appears to have held up well over many years.

http://www.toymods.net/forums/showthread.php?t=27865

http://www.toymods.net/forums/showthread.php?t=9000

[MWP]

I stitch welded my RA28 chassis, front to back.
Never had any problems with distortion of panels or chassis (as far as i can tell).

[Joshstix]

points noted thanks guys,

what other recomendations would u have for stiffening her up?

i am already planning a bond bolt in half cage and a rear strut brace.

cheers
stew

I think stitch welding is the goods. I just think doing it all over so that the strength of the chasis is improved evenly would be the best situation, obviously in your situation destroying the lovely paint job you've got wouldn't be option number 1.

You could fill the sills for some extra stiffness but I don't like the idea really. I guess my concern is that if you stiffen up the front by stitch welding the engine bay and stiffen the rear by fitting a half cage then we're in a situation where the week area is where the more valuable "soft bits" tend to be carried in tha cabin.

I'm probably just being a worry wart though. A lot of people do this and don't seem to have too many problems, at least not that they tell you about.

[Toy77]

Yeah, i hear wat you are sayin Josh - i have had similar thoughts myself. but i was unsure whether it is better to have one area moving, or the whole lot lol.

MWP - you haven't driven your car yet have you? to see the effect of thewelds?

Cheers
Stew

[1JZ.747]

Have a look at what TwinTurboCelica has done to his 1J RA28 for ideas as that thing has seen a lot of track time and appears to have held up well over many years.

http://www.toymods.net/forums/showthread.php?t=27865

http://www.toymods.net/forums/showthread.php?t=9000

paul has told me in the past the roof is bent in his celica. this happened prior to the roll cage, i cant pick it with my eye but he can.

[barned01]

do you have measurements to confirm that the chassis is straight to begin with before stitch or seam welding it?
seems no point if you are just stitching a bent chassis to begin with....