Sons first car. 521

[TJ H]

So new issue. We finally got the roadster manifold and it fits like space was tight and very much not for a 521. Are there any off the shelf head pipes or should I just start cutting and welding?

 

https://postimg.cc/dhV3Wjp4

[datzenmike]

 

Exhaust manifold??? Looks like L16/18, 4 into 2 manifold to me. Nothing on the Roadster engine will fit the L series.I have one on my L20B.

 

 

 

 

 

[TJ H]

Yup. N23. Son liked the old school look and informed me that manifolds lasted longer than headers and the 4to2’s didn’t cost power with restrictions. The head pipe is aimed toward the e-brake and corner of the bell housing. Will take some re-engineering to route this. What did you do?

 

https://postimg.cc/v4KY0FWZ

 

 

[wayno]

That exhaust manifold is made for that truck, it may be close but it should clear everything, all you need is the 2 into 1 "Y" pipe that bolts onto the exhaust manifold.

[TJ H]

11 minutes ago, wayno said:

That exhaust manifold is made for that truck, it may be close but it should clear everything, all you need is the 2 into 1 "Y" pipe that bolts onto the exhaust manifold.

It came with a 2 into 1 but I don’t know what it is off. The bends were completely off and the torsion bar is completely in the way. Does anyone have the correct one I can buy? Either that or I am going to reinvent the wheel. 

[DanielC]

This may help you.

https://ratsun.net/topic/61167-how-i-replaced-a-521-exhaust-system/?tab=comments#comment-1066487

 

[TJ H]

5 hours ago, DanielC said:

This may help you.

https://ratsun.net/topic/61167-how-i-replaced-a-521-exhaust-system/?tab=comments#comment-1066487

 

Thank you. I have already got the pieces to make his exhaust. That did show me I do have the wrong head pipe. The one he use is drastically shorter. 

 

https://postimg.cc/gallery/10hupkavi/

 

[wayno]

That down pipe in your photo below is not for a 521, maybe it's for a 510?

 

 

As for the exhaust manifold pointing at the e-brake system/bracket, something else is going on here, it appears you have the proper engine mount bracket in the photo, the motor mount may be the correct one but it looks a little tall, and that exhaust manifold belongs in that truck, so you have a 5 speed in the truck, I wonder if the transmission mount is holding the transmission tail too high therefore pointing/angling the exit of the exhaust manifold more towards the e-brake bracket or maybe it is just you need the proper head pipe/down pipe.

I also have heard in the past that putting the L16 exhaust manifold on the L20b there was an issue with the down pipe hitting the transmission case, that has never happened to me that I recall, but until recently I have used a header on my 521 work truck, now I have a stock L16 exhaust manifold and a custom exhaust system past the "Y" pipe and it is very close to the transmission, I have to remove the exhaust to even move the transmission backwards a couple inches.

[TJ H]

34 minutes ago, wayno said:

That down pipe in your photo below is not for a 521, maybe it's for a 510?

 

 

As for the exhaust manifold pointing at the e-brake system/bracket, something else is going on here, it appears you have the proper engine mount bracket in the photo, the motor mount may be the correct one but it looks a little tall, and that exhaust manifold belongs in that truck, so you have a 5 speed in the truck, I wonder if the transmission mount is holding the transmission tail too high therefore pointing/angling the exit of the exhaust manifold more towards the e-brake bracket or maybe it is just you need the proper head pipe/down pipe.

I also have heard in the past that putting the L16 exhaust manifold on the L20b there was an issue with the down pipe hitting the transmission case, that has never happened to me that I recall, but until recently I have used a header on my 521 work truck, now I have a stock L16 exhaust manifold and a custom exhaust system past the "Y" pipe and it is very close to the transmission, I have to remove the exhaust to even move the transmission backwards a couple inches.

I bought 521 engine mounts which were completely wrong so those are 510 mounts that were the same as the old dimensionally. The tranny mount I tried to get as low as possible. It is sitting at 4.5 deg tailshaft down. The pinion is 5deg up so I am within 1 deg for vibrations and with the rake of the truck were level. I think a different head pipe would fix my problems. I already cut the long one apart and when I reverse the bends I can clear the torsion bar. I have a header also but my son is a PITA. 

 

[TJ H]

This is what I mean by aimed toward the bell and e brake. Slight bends are needed to clear. 

 

[datzenmike]

1 hour ago, wayno said:

That down pipe in your photo below is not for a 521, maybe it's for a 510?

 

 

 

 

This is a 510 down pipe. The '73 610/ '74 710s both with L18s had a similar two pipe with the top pipe just bend downward and joined into the top side of the bottom pipe. There was no Y fitting. These are the only vehicles with that manifold. 521/510/610/710.

.

I doubt Nissan went to the bother of an exhaust manifold for the truck and the 510. Much easier to design and bend the down pipes to fit the vehicle. No way being 3/4" higher will hit the transmission on an L20B. The floor under the feet might be a different matter.

 

 

[wayno]

In my opinion that transmission mount has the transmission tail too high, this is what the stock 4spd transmission mount height is, it sticks way above the cross member.

 

This is how high the top of the mount should be above the cross member with a 5spd.

 

This may not be a lot of difference at the exhaust manifold, but an eighth inch can be a lot in the big picture, yours appears to be way higher but it is hard to tell from that angle, I have my transmission mount surface that the mount bolts to level with the bottom transmission mount bracket lower mount bolts.

 

 

[TJ H]

1 degree of drive line angle is actually a lot of actual movement at the extremities. Most manufacturers set the drivetrain at 3 degrees. I set mine as low as possible but still allowing for mount flex. I read your post before doing mine and it is about the same. I am running a different style mount though.  In your picture the torsion bar  Arms are not installed. That was another space constraint to consider. Even sitting on the cross member I was at 4.5. Raising for clearance had no effect on angle readings. 

[wayno]

That last photo in my last post is of the stock 521 transmission mount(on my mount bracket) which appears to be the same transmission mount as the one in your photo, my mount has the top of the transmission mount likely 1 to 2 inches lower, the reason I made the mounts this low was to keep the transmission from hitting the tunnel, yours may not hit your tunnel with the cover in place, but I went about this avenue of thought because of the exhaust manifold e-brake interference issue you say you have, the lower the tail shaft, the more clearance you will likely have in that area.

Edited September 29, 2019 by wayno

[TJ H]

Agree. Bellhousing issue is locked into the engine itself but definitely the brake issue. I’m clear on the tranny cover with exception of the relocating the shifter hole. Datsun seem to have a lot of issues with every component change. 

 

[banzai510(hainz)]

clevermartin01@gamil makes a little Y pipe  then one can adjust for the torsion bar routing.

most of those 521 are gone by now unless soembody has a good one

[TJ H]

9 hours ago, banzai510(hainz) said:

clevermartin01@gamil makes a little Y pipe  then one can adjust for the torsion bar routing.

most of those 521 are gone by now unless soembody has a good one

I sent a message. Thank you. 

[banzai510(hainz)]

I sent one also but haven't gotton a reply yet

[d.p]

This is what martin sells when you can get a hold of the guy.  

 

[TJ H]

2 hours ago, d.p said:

This is what martin sells when you can get a hold of the guy.  

 

He responded to me with a price. I ask for pics. It’s nice but they are pricey. 

[banzai510(hainz)]

Yes he responded back to me.

He says just looks like  it in the photo. THEY NOT WELDED TOGETHER!!!!. which needs to be welded with stainless rod, Im assumeing as he said it was a stainless part

 

I was hoping like the photo but a 4 or 5 inch collector welded on also would help. (also justifly the price for me)

 

be nice if he made a generic run of a full Y pipe system to a 2inch wide say 4 inch long collector that fits early 510/521/620s

 

Edited October 1, 2019 by banzai510(hainz)

[TJ H]

1 minute ago, banzai510(hainz) said:

Yes he responded back to me.

He says just looks like  it in the photo. THEY NOT WELDED TOGETHER!!!!. which needs to be welded with stainless rod, Im assumeing as he said it was a stainless part

 

I was hoping like the photo but a 4 or 5 inch collector welded on also would help. (also justifly the price for me)

 

He mentioned the welding part. The rest of the exhaust system is stainless so that is a selling point. 

[banzai510(hainz)]

ask if he could weld it up.

I don't want to find a local guy here to charge me another 40$ then put a collector on $$$ on then weld up the exhaust.

 

I just want a bolt in ready spare

[TJ H]

4 minutes ago, banzai510(hainz) said:

ask if he could weld it up.

I don't want to find a local guy here to charge me another 40$ then put a collector on $$$ on then weld up the exhaust.

 

I just want a bolt in ready spare

Agree. Welded with a 2.25 collector and I would be good to go. 

[banzai510(hainz)]

I just wrote him saying that I think 2inch collector that is 3 or 4 inch in length complete assembly is more than fine up to a true 125hp to the ground which I think is rarely met on Ratsun L motors.  Turbo maybe different.see wht he says.

I just wanted a spare set. I have a Y pipe on the side already but ber nice to have a new one with a spare Cast iron manifold with stainless bolts ready to bolt it on