289monster

Has anyone had this issue with the monster miata headers? The driver side hits the frame rail quite a bit. The pictures shown are of the bolts completely loose. I need about another gasket width to close the gap. Im using trick flow twisted wedge heads with a 289 block. I also had to port match and slot the header bolt holes to get the runners to line up with the exhaust ports. Not sure if i want to notch the frame rail. Any ideas? Will coping out the frame rail do any harm?

Sunshine Guy

I have read of several people shifting the engine off center, 1/4" or so over towards the passenger side in order to gain the necessary clearance.

norotors

My driver's side rail is notched a fair amount (3/4" maybe) and it has had no noticeable effect in the 23 years the car has had a V8 in it.

norotors

By the way, I am insanely jealous of your garage cabinets!

V8MiataMike

How does the oil pan look where it sits down inside the K member? Is it really close to the edge of the K member on the driver side?

By flipping engine mounts, swapping sides with the rubber mounts, etc, I was able to shift the engine to the passenger side. I also did some slotting to get the extra 1/4 inch. When I was done the oil pan centered up in the K member (the large part of the pan that sits behind the K member that is). No problem with header clearance or steering shaft clearances even with additional thickness of header wrap.

norotors

I will check out the oil pan issue when I get under it this weekend. Mine is not a monster kit if that's what you are using to do your swap. Mine was done by a shop back in the early 90's, so I am not sure what mounts, etc they used.

I have about 1/4" clearance between my wrapped headers and that brake line in your photo. Yours looks like its lying right on that header tube - not a good thing. I am actually thinking of rerouting my brake lines to a cooler spot. Something you may want to consider.

V8MiataMike

The brake line is actually not touching the header as it looks in the picture but it sure is close in one particular spot! I have it wrapped in heat tape and in this picture it also has wire loom on it.

I do have the Monster kit so that is where the K member, mounts, etc. came from.

By the way, that is a NICE looking build!

charchri4

IMO that wire loom won't make it 15 minutes into the first start up before it fries and I see a real danger of boiling the fluid there. I'd move that brake line for sure.

It wouldn't take much to find a passenger side line from a part out and run it around the front of the engine far away from that header.

Just my unsolicited .02 for the day...

V8MiataMike

Jim, you are wrong on this one. It lasted 16 minutes into the first start up (OK, I didn't really time it... who knows!).

I put it there as a test to see just how much the header wrap might help. It kind of melted but sagged more than anything and and sort of smoothed out the ribbing. It never actually melted on to the brake line. I simply removed it due to its "deformed" shape. And it was "imported" plastic from ebay so...

To really improve the routing of both front brake lines, the transition mount (tube to hose fitting point) under the frame rails would need to be changed as they sit right on top of the header collector area in heats way.

Mike.

MX-Brad

I'm struggling a bit with this too. My passenger side isn't too bad, but my drivers side looks similar to yours...maybe 1/4" clearance, if that. I won't be wrapping my headers.

WWJD ?
(what would Jason do?)

V8MiataMike

At a minimum, get that heat tape to wrap around the brake tube. I have not had any noticeable brake problems since day one on my car. They felt good before the conversion and good now after the conversion - no difference as far as I can tell. I moved the driver side brake tube as far towards the firewall as possible (no longer in the original stock clip on the frame rail side) so that it lined up with the most clearance relative to the header shape. But there is still that issue with the tube/hose joint being right above the collector. I bent the bracket a little to move it away from the header as well.

But no brake problems, no issues. Been on many many short runs and a few long highway runs - no problems.

MX-Brad

Ya, I'm out in the garage right now, and I was able to bend a little more clearance into the line. Mine is routed similar to yours snd I put the heat tape on when I taped my fuel lines. All should be good.

charchri4

This might be a dumb question but in my minds eye this looks like a simple solution. I remember when I seam welded the entire world the metal in the inner fender is really thin where that brake line runs. Have you considered drilling a hole and just running it around the outside of the frame rail rather than the inside?

289monster

I ended up drilling new holes in the K member engine mounts 1/2 inch towards the passenger side. I also drilled new holes in the transmission crossmeber 1/2 inch towards the passeger side and had to modify the actual tranny mount itself to do so. This was to regain the proper tail shaft alignment. I also lowered the engine about 3/8. With all of these moves i was able to fix the header/frame interference with now about 1/4 air gap and clear my 13 inch diameter air filter element with the stock hood. Thanks for the input!

289monster

I ended up drilling new holes in the K member engine mounts 1/2 inch towards the passenger side. I also drilled new holes in the transmission crossmeber 1/2 inch towards the passeger side and had to modify the actual tranny mount itself to do so. This was to regain the proper tail shaft alignment. I also lowered the engine about 3/8. With all of these moves i was able to fix the header/frame interference with now about 1/4 air gap and clear my 13 inch diameter air filter element with the stock hood. Thanks for the input!

V8MiataMike

Jim, that would be the best solution for sure. The passenger side could use the same mod too. However, I have had no noticeable problems so I'm waiting till the heat of summer to make the final call...

charchri4

It must not be much of a problem or Martin would be re routing them on all his cars too. It just seems to me (as someone who boiled brake fluid more than once) that you'd want to do everything you can to insure you don't have brake problems before you do.

That's one fine looking car 289monster!!!