Inside frame rails mufflers/exhaust - v8 (1 Viewer)

[Strait Cruisin]

I'm about to do the exhaust on my glacially progressing rebuild. I remember seeing some frame off pictures a while back of a really nice example of twin mufflers mounted behind the t-case. I thought I saved them but over the years there's lots of stuff I thought I saved. Anyone have pictures of such a mod? I've been running short pipes leading to mufflers right under the running boards and that hot foot nonsense has to go.

 

[Downey]

Problem is designing the pipe the goes from engine to muffler, it becomes a piece of art when staying inside the frame rails. On 3 speed tranny models the drivers side pipe must clear the oil filter, slave cylinder, and shift fork travel. Your 4 speed then should have that problem on the passengers side?????

 

[Strait Cruisin]

Problem is designing the pipe the goes from engine to muffler, it becomes a piece of art when staying inside the frame rails. On 3 speed tranny models the drivers side pipe must clear the oil filter, slave cylinder, and shift fork travel. Your 4 speed then should have that problem on the passengers side?????

I have a 4sd. The pics of the install I recall used specific rear dump manifolds, I didn't have casting numbers or applications where they came from but the pipes were a bowl of spaghetti. It was a prettier bowl of spaghetti than mine though. I'll dig through some old files, maybe I'll get lucky.

I have the body loose on the frame now, maybe I'll just take it to the local shop and leave it and my wallet there with some loose instructions and see what I get back. I crack myself up sometimes....

EDIT: you the Downey of old or related? I have an early '80's catalog from them

 

[Living in the Past]

Problem is designing the pipe the goes from engine to muffler, it becomes a piece of art when staying inside the frame rails. On 3 speed tranny models the drivers side pipe must clear the oil filter, slave cylinder, and shift fork travel. Your 4 speed then should have that problem on the passengers side?????

I think a three speed that still has the vacuum shift transfer case would create a nightmare trying to stay inside the frame rails and not hang down below the frame. Add a PTO on the driver's side and really talking a piece art to get one in there.

 

[Oxblood]

I think my FJ40 has what you are looking for. When I get off from work I'll take some pictures.

 

[sadam_husain]

that's a really big ask mate but anything is do-able if your prepared to spend the time making it work, we did twin 2 1/2" pipes like that on my fj75 with an LS engine but the frame is a little wider and it had a 2" body lift with made a huge difference with clearance, we did it with the body loose (single cab) so we could remove it to make up the pipes and keep putting it back on for test fitting

 

[tlc762]

I had it done in my 10/73 (swapped to 4 speed during the conversion using a kit from @Downey ) years ago at a local muffler shop. Used a ramhorn manifold on the right side and 3/4 dump manifold on the driver's side (Cause that was what I had at the time). Right side goes under the oil pan in front of the sump and runs right below (or next to-I can't remember which) the drivers side pipe. Then dual mufflers side by side(the long oval axis is vertical on both mufflers and they're welded together side by side) behind the transfer case then both pipes go over the axle and exit behind the left rear tire. I had already lowered the skidplate an inch for clearance on the 4 speed and had the pipes run above the skidplate next to the trans/tcase. Will try and shoot pics in the morning...
HTH,
Will

 

[reddingcruiser]

I've run dual exhaust on multiple SBC 40s. Running an A/T makes it a bit easier because the t-case is further back in the frame.

 

[Strait Cruisin]

I think my FJ40 has what you are looking for. When I get off from work I'll take some pictures.

You're my new best friend.

 

[shawnfj40]

Running duals on a 40 is kind of overkill IMHO. Unless your planning to race it a couple of 1-1/2 or so inlet pipes to a single muffler and a single tail pipe from there should be fine. An alternate is a Y-pipe with a single in/out muffler. The only thing to really be concerned with is that the pipe gets larger as it progresses to the exit. Ie. 1-1/2 from the manifolds to a 2 inch collector 2 inch in 2 1/4 out on a muffler 2-1/4 tail pipe to the exit. Any variation can work. Running duals all the way back would be tough unless you own a muffler shop

 

[Oxblood]

Here's what I got... It's hard to get pictures down there. Took a video, maybe that helps, ignore the rust, we are just getting started with this guy!

 

[Downey]

Oxford, your engine must really be forward to allow use of a rear dump manifold on the passengers side????

 

[Strait Cruisin]

Oxford, your engine must really be forward to allow use of a rear dump manifold on the passengers side????

Thanks for the video and pics. This is very close to what I want. Have you ever had the belly pan on with those pipes?

Mine uses the same manifold. I did the swap with an AA adapter in the early '80's and moved the trans/tcase forward quite a bit. I run a Taurus fan with dual temp sensors to start the low and high speed fan speeds, I tried a water pump fan but overheating was a problem.

I found this post from about 7 years ago. It looks like a chrome plated turbo 350 pan in it though and not a 4 speed. I remember some other posts too and still searching.

Headers on fj40 chevy 350

 

[Strait Cruisin]

40...race

There's two words that don't belong in the same sentence.

 

[Oxblood]

Oxford, your engine must really be forward to allow use of a rear dump manifold on the passengers side????

Dunno what would be considered far forward, my wife's dad built this in the 90's and I'm just learning about FJ40s. I usually stick to vintage bikes...

Thanks for the video and pics. This is very close to what I want. Have you ever had the belly pan on with those pipes?

Mine uses the same manifold. I did the swap with an AA adapter in the early '80's and moved the trans/tcase forward quite a bit. I run a Taurus fan with dual temp sensors to start the low and high speed fan speeds, I tried a water pump fan but overheating was a problem.

Yeah it has full pans that go all the way back, I just happen to have them off right now from rewiring it. This one runs a clutch fan and did fine for years in Moab. I'm having a little heat problem now that I live in Vegas, I'm hoping a aluminium radiator will help. Just waiting on champion to get retooled to make the one I want.

 

[tlc762]

 

[tlc762]

Here's the pictures of how my mufflers were mounted (above). Don't hate the bailing wire hanger- I live in Texas afterall...

 

[tlc762]

Here are the pipes. The wrapped pipe goes under the oil pan to the passenger side.

 

[tlc762]

 

[Strait Cruisin]

Dunno what would be considered far forward, my wife's dad built this in the 90's and I'm just learning about FJ40s. I usually stick to vintage bikes...



Yeah it has full pans that go all the way back, I just happen to have them off right now from rewiring it. This one runs a clutch fan and did fine for years in Moab. I'm having a little heat problem now that I live in Vegas, I'm hoping a aluminium radiator will help. Just waiting on champion to get retooled to make the one I want.

I put a new 4 core with a taurus fan and some summit racing temp senders. no more heat problems (this was high desert of eastern OR / southeast ID).

I'm getting ready to put the tub back on for the last time and it'd be nice to get the exhaust I want done before. Its so much easier to weld standing up than lying on a creeper when a glob of slag decides to meet up with you in your underwear.