351W Header to side pipe fittment issues

[Rebostar]

I'm having an issue with the Pax side (right) header to side pipe alignment. First let me reassure you that the engine is sitting square to the frame. Checked and double checked. Engine is level. Both pins 1/16" below the top of the mount groves. So I know the engine is installed correctly and is square and level. The issue is the right header is 1.25" higher than the left (drivers side) measured just inboard of the ball flange. The left side pipe went on just as advertised. No shims, just a gasket. The pipe is level and square to the body and the lower mount aligns as it should. Left side= everything is groovy! Right side not so much. When I did a mock up for the "go cart" I noticed the differance and ordered up two 1/4" and one 1/8" tapered shims from Breeze. I thought that would "fix" the issue. Not so much. I used both the 1/4" tapered shims to direct the pipe downward and used most of the ball flange just to get the side pipe square to the body. Now the issue is the side pipe is 1.25" inches higher than the left. I would not worry about it because you cannot look at both headers and side pipes at the same time so who would ever notice? Except that with the side pipes that high the rear attach bracket would not fit per FFR. I can however modify it to work, which is my plan in the morning by welding a vertical extension on the bracket.
I called F500guy (Lance) and he measured his headers and the right side is also 1.25" higher than the left. So he has the same issue.

So what are folks doing to remedy this? If I order another header or set of headers from FFR I'll end up with another set that was not welded correctly in the jig. I'm sure the angle of the head base plate to the 4 pipes is off by between 3 and 7 degrees thus accounting for the 1.25" discrepency.

I thought about removing the header and heating the collector pipe up cherry red and bending it downward. That would ruin my $350. Ceramic Coating job.
Or I can leave it as it is.
What other options have you guys come up with?

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[rich grsc]

The engine doesn't set level. Loosen the motor mounts, raise the driver side 3/4" and you'll be so close no one will know

[Rebostar]

The engine doesn't set level. Loosen the motor mounts, raise the driver side 3/4" and you'll be so close no one will know

Rich
Read the first line. The engine is level and square to to the 4" tubes. Checked with a level accross the 4" tubes, along the 2" cross tube, the heads, the intake manifold, and the carb. Then engine is level and square to the frame. Both right and left alignment dowels are exactly 1/16" from the top of the mount slots. The engine cannot be rocked or rotated. Any other positive suggestions?

[gbranham]

I think what Rich is saying is the engine doesn't have to sit level. I leveled mine, and then a few weeks later, I installed my headers and sidepipes for a test fit. The passenger side was about 2" higher than the driver's side. I loosened the motor mounts and adjusted the engine to lower the passenger side an inch, which brought the drivers side up an inch. They are now at the same height, and the engine is not level, but that's not a problem. I think folks fixate on getting the engine level, which is unnecessary.

[Mike.Bray]

I think what Rich is saying is the engine does not usually sit exactly level. I had the same issue and had to move the mounts around some with a C-clamp to get my headers level. Raise the DS some and lower the PS some. It won't take much to make a big difference out on the end of the headers.

[Jeff Kleiner]

I'm another one saying that if you rock the engine just slightly at the mounts it makes a BIG difference out at the sidepipe due to the length of the pipes. I've done it many times. That said and not to state the obvious but can't you just loosen the ball flange and rotate the intermediate pipe and sidepipe downward?

Jeff

[Rebostar]

I called FFR this morning and sent them a batch of pics. A couple of the engineers looked things over and really had no solution. They recomended I rock the engine over as you guys mentioned above. But that would have the effect of having both sides a half inch high and niether side bracket would fit without modification and the engine would no longer be level with the frame. In addition to that I'd have to raise the engine, remove the mounts, then add an additional 1/4" to the pin slots in the mount brackets. Right now both the pins are maxed at the top of the slots. So having one side correct (Left), the engine level to the frame, and one side (Right) 1 inch higher than the other is preferable to all three being out of spec. So thats what I'll do for now. Keep the engine level, have the left side correct and modify the right bracket to mount the right side a bit higher.
I'm certain the angle of the cylinder attach plate of the header was welded to the primary pipes at an incorrect angle. Only a few degrees would give you the 1.25" deviation at the end of the header. Another builder with the same engine and headers as I have, measured his headers and found the right side 1.25" higher than the left, exactly like mine. So this is not unique to my installation. The good news is no one can see both headers and side pipes at the same time. But the perfectionist in me is having a hard time with it.
Below are a few pics of the installation. Tomorrow I'll modify and install the right attach bracket.
Thanks for the input guys.

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[Norm B]

Those are the new headers with the ball and socket joint. You should remove the support brackets, loosen the ball and socket joint bolts, position the side pipes where you want them and then retighten the ball and socket bolts. The joy of a ball and socket joint is that it doesn’t have to be lined up straight to seal. You should have enough range of motion with tilting the engine and adjusting those joints to easily match up the sides.
Once you have everything set up the way you like it, modify your support brackets accordingly.

Norm

[Mike.Bray]

When I recently reinstalled my engine the PS header outlet was way too high. The DS was pretty close but not exactly where it was. Since everything had been together before I was confused as to what happened. Looking closer I could see the motor mounts were out of position in reference to the frame and I didn't see any way I would be able to get the amount of correction I needed.

Using a good size Wilton C-clamp on the motor mount and frame I was able to force both sides into their correct position. If you look at the picture below you can see the upper position where I started and where I ended up. From what you're describing it sounds like you've got some room for additional adjustment. A small adjustment here makes a big difference out on the end of the header as I saw first hand.

https://www.imagecoast.com/images/MichaelBray1/20241217173210.jpg]

[Rebostar]

Thanks much for the input and suggestions everyone. Upon very closer inspection both the right and left mount pins are locked into the very top of the slots. Hence no room to roll it without more serious surgery. With the two Breeze tapered shims and a bit of coaxing I have it now where the right side pipe is one inch above the left and level to the bottom of the car and the clearance with the body cutout is acceptable. I did have to make use of the ball joint (thanks Norm). I modified the right lower bracket (see build thread) and all the bolts slide in with moderate hand pressure. So I'm gonna call this a wrap.....................for now!

[kevin j sullivan]

By your above process of elimination, it's in the motor mounts. Reset the motor mounts. Not a big deal. I expected this and had to do it on my 351 windsor.

[Claybuster]

This is a great discussion! As I will be at this stage in a few weeks, I have a quick question along this same line. When rotating the engine, what does the group do about the transmission mounts? Do you find that you have to add/subtract anything from them as well?
Thanks, and keep it going!
Jason

[ggunter]

I had an issue with the headers being too high on both sides when I went from the 347 to the 427 windsor. I bought the 351 headers from FFR but they would not fit due to being too high. I ended up pie cutting 3/4" on the bell flange and bending the pie cut closed and tig welding the cut shut. This angled the bell downward to give me the angle I needed to bolt the side pipes on. I still had to adjust the body opening slightly but it worked out pretty well in the end.

[Mike.Bray]

I went from the 347 to the 427 windsor.

Out of curiosity, how much difference was it driving the 427 vs. the 347? Would you do the 427 again?

[Rebostar]

I had an issue with the headers being too high on both sides when I went from the 347 to the 427 windsor. I bought the 351 headers from FFR but they would not fit due to being too high. I ended up pie cutting 3/4" on the bell flange and bending the pie cut closed and tig welding the cut shut. This angled the bell downward to give me the angle I needed to bolt the side pipes on. I still had to adjust the body opening slightly but it worked out pretty well in the end.

Great point, the 302W/347W has the lower deck hieght, the 351W/427W is an inch taller at the center, probably 3/4" at the head exhaust ports. That would account for the almost an inch too high on the header tips.

[CraigS]

2 techniques that may help re; mounts. 1- Look at the mounts. You have a layer of steel, a thick layer of rubber and another layer of steel. When you try to jack the engine around to get the frame side steel to slide it usually will not move. Grab a 2x4, or prybar, or piece of pipe and lever or pound directly on that steel w/ the stud. Now it will slide in relation to the frame. 2- Look at the bolts that connect the mount to the engine block. A hardened washer or 2 between the mount and block will tilt the engine pretty significantly.

[Norm B]

In addition to Craig’s advice, you can support the engine to take the weight off the mounts, loosen the block to mount bolts and the mount to frame nuts, then pry the mounts to a lower position while slowly lowering the engine. Once in the position you want tighten the mounts to frame nuts then the mount to block bolts.

Norm

[ggunter]

Hi Mike, yes, I would definitely go with the 427 again. While the 347 is a marvelous engine, (and I still have it as a spare) the torque difference between the two is huge. The slam you in the seat factor is also huge. Puts a smile on my face every time i let her eat.:cool: