swap a gs400 engine into a gs450

[Loubob]

can i swap a gs400 into a gs 450. Any tips if it can be

[SVSooke]

A 77 or so GS400 engine?Not a direct swap as the engine mounts are different.Should be do able with some fabbing.The later 80+ TSCC Canadian model engine should be a direct swap though,same bottom end as the 450.

[Loubob]

Thanks, the ones I am looking at are both 83's. Is for a future product if I can get them at the right price

[jfman]

make sure you get the exhaust and intake manifolds because those dont interchange between the two engines.

[Mekanix]

I think the exhaust might be pretty close.

[Qhergt]

So, did I read that correctly? I can fit a 450 onto my 82 gs400T? What about a 500?

[jfman]

So, did I read that correctly? I can fit a 450 onto my 82 gs400T? What about a 500?

The 500 you cant because the exhaust ports are directly in line with the frame spar.

[Mekanix]

You can fit the engine in the frame with no problem. The base and mounting points are the same.
The head on the 500 has exhaust ports that point straight towards the frame.

But a gs 450 with a gs 500 block and pistons combined with the 450 head is the way to go.

[wera90ex]

But a gs 450 with a gs 500 block and pistons combined with the 450 head is the way to go.

You can also use a GR 650 head. Use the GS 500 head & base gskt. Switch the cam sprockets and you can use the 650 cams too. Oh yeah, you have to plug the EPA sigots that go into the intake tract. Burns-o-matic and soft solder works great.
If your a bit industious you can also use the GR650 pistons by trimming the skirts of the pistons. It makes it a 527cc. http://www.youtube.com/watch?v=tQEVHd1cSyw

[Mekanix]

You can also use a GR 650 head. Use the GS 500 head & base gskt. Switch the cam sprockets and you can use the 650 cams too. Oh yeah, you have to plug the EPA sigots that go into the intake tract. Burns-o-matic and soft solder works great.
If your a bit industious you can also use the GR650 pistons by trimming the skirts of the pistons. It makes it a 527cc. http://www.youtube.com/watch?v=tQEVHd1cSyw

Gr. Head ?
It does not work without modification and you will have a ccompression ratio of 6:1 even if you used the gr pistons.

The 400 base does not have the stroke the gr has.

450 heads have the smallest combustion chamber.
Gr650 has the largest.
500 is in the middle.

[jfman]

So if you get your hands on a whole GS500 engine, you can just install your GS450 head on top of it and be done...?

Use the 500 cams on the 450 head?

[Mekanix]

I can't remember the exact numbers now but I believe the cams are the same spec.
You have to swap out the shift drum too.

The gs500 is backwards compared to the 400 and 450. So up would be down.

[wera90ex]

So if you get your hands on a whole GS500 engine, you can just install your GS450 head on top of it and be done...?

Use the 500 cams on the 450 head?

The one in the pic is a GSX400 bottom. Also have a (612cc) and a (578cc) engines for this season. All with the same head- cyl combination.
You can use the 500 cams in the 450 head. The 650 cams are marginally bigger, but they are bigger. Actually have a set of 650 cams in my GS 500 practice bike.

[wera90ex]

Gr. Head ?
It does not work without modification .

Really? I wish you'd have told me 10 years ago........... I keeeeed! I keeeeed! Yes, there are a few things you have to mod.

[wera90ex]

This is what was on the bench.