340 Chrysler Street Header Questions
Moderator: Team
Re: 340 Chrysler Street Header Questions
On the bench with the first merges. Also a better view of the lengths and step up. The slip joints didn't work out - at least where originally planned.
Since the header is now one piece, it has to be removed and reinstalled from from underneath. To do this, the steering column, starter and pitman arm were removed. We'll continue to revisit making the header multi-piece as it goes along.
Bringing the upper secondary down will be another difficulty. We'll probably modify the kickdown's bellcrank to position the lower arm closer to the transmission.
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Re: 340 Chrysler Street Header Questions
Secondaries welded on
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Re: 340 Chrysler Street Header Driver Side Done
The driver side is basically done. It will come out one more time for
final welding with collector.
Tube clearance is good except the one by the steering box and the merge
next to the torsion bar. The latter has me a little worried it may rap against
especially if I step the t-bar up one size (larger diameter). Ground clearance is as good as, or better than Accurate's reproduction headpipe
for the cast 340 manifold.
That's awsome.
final welding with collector.
Tube clearance is good except the one by the steering box and the merge
next to the torsion bar. The latter has me a little worried it may rap against
especially if I step the t-bar up one size (larger diameter). Ground clearance is as good as, or better than Accurate's reproduction headpipe
for the cast 340 manifold.
That's awsome.You do not have the required permissions to view the files attached to this post.
Re: 340 Header Right side is a bit tight...
So here is why a 4 in 1 might be a better choice on a LH drive Chrysler a-body.
Right side is actually looking more troublesome than the left. Brian was finding no room to take all 4 tubes inside the torsion-bar. The problem as I see it is the merges need to be straight and the combo of the oil filter an steering link means forces turns.
So far the only way I can see it can be done would be to truncate the primary tubes.
So short, I don't know what would happen performancewise.
And as far as the builder is concerned, its not even close to his standards.
The only way may be to run on both sides of the torsion-bar. Unfortunately this places one pair super close to brake and fuel line - and
that could be bad. Fuel under suction doesn't like heat. If we go this route, and I think will have to, more aeroquip firesleeve will go on and try to route the
fuel line higher on the frame rail. (It's already stainless hard line)
I'm open to installing a remote filter - there's probably room, but Brian doesn't think its going to buy the space needed. The only left hand drive comparison tri-ys I'm aware of are the Schumacher and early Spitifire. The Schu photo provides a good sense of the turns needed to clear the t-bar, oil filter, and steering link. as you can see, it uses much shorter primaries and merges.
Right side is actually looking more troublesome than the left. Brian was finding no room to take all 4 tubes inside the torsion-bar. The problem as I see it is the merges need to be straight and the combo of the oil filter an steering link means forces turns.
So far the only way I can see it can be done would be to truncate the primary tubes.
So short, I don't know what would happen performancewise.
And as far as the builder is concerned, its not even close to his standards. The only way may be to run on both sides of the torsion-bar. Unfortunately this places one pair super close to brake and fuel line - and
that could be bad. Fuel under suction doesn't like heat. If we go this route, and I think will have to, more aeroquip firesleeve will go on and try to route the
fuel line higher on the frame rail. (It's already stainless hard line)
I'm open to installing a remote filter - there's probably room, but Brian doesn't think its going to buy the space needed. The only left hand drive comparison tri-ys I'm aware of are the Schumacher and early Spitifire. The Schu photo provides a good sense of the turns needed to clear the t-bar, oil filter, and steering link. as you can see, it uses much shorter primaries and merges.
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Re: 340 Chrysler Street Header Questions
Well I am impressed with your work. I see it looks pretty tight. That Pass side looks just fine.You do not have to worry about having straight sections off the head. You can use the room to start turning sooner, just like your number 4 tube in the pic, although it looks a bit cheated. Your better off using a tighter radius than cheating the radius to fit things in. I would do everything I can to avoid using a 2" radius when using 1.63 off the head. 2.5" does get used a lot. For your power level I would have gone with 1.5, just making sure the roof and sides were nicely done. It is not easy.
I don't build primaries that long. Max of 18". Those look at least 22" or so. It is ok for your application but you have to pack more tubing in and it is not necessary. Make the secondary longer. Seems most engines want the secondaries longer, not the primaries.
Those flanges are a lot of work and SS? But it looks like you did a nice job of transitioning to the round tube.
I avoid SS unless customer wants it.
Interesting. I recently recieved a call from a NHRA stocker 340 and I will do it if it works out. Never done one before. Done 383's and bigger stuff.,never a 340. Been wanting to do one for a while.
Hope it works out. Reming me and I will post some pics if I do them.
And by the way, 900HP said it right, you do the swedging on the bottom, never the top. This is called blacksmithing. You have to shape the tube as much as possible by hand to fit the irregular shapes on the top and sides and blacksmith the floor down to the flange if the tube is being enlarged. I will have to lay all that out in my blog some time soon.
This also means you have to fit each tube from each port exactly where you want it to go. Most folks make all the tubes, weld them up and weld them into the flange last. I make the tube off the head right where it needs to be and finish the tube to flange fabing and welding. Then I finish each tube the rest of the way to collector. When you realize the power/flow is most important at the port/header transition, how can you do that last. You usually do not get things good enough.
Here is a shot of a 383 in a 62, sort of the same issues. They are actually 1 5/8" off the head.
You can see the step to 1.3/4 about 8" out from the head.
I don't build primaries that long. Max of 18". Those look at least 22" or so. It is ok for your application but you have to pack more tubing in and it is not necessary. Make the secondary longer. Seems most engines want the secondaries longer, not the primaries.
Those flanges are a lot of work and SS? But it looks like you did a nice job of transitioning to the round tube.
I avoid SS unless customer wants it.
Interesting. I recently recieved a call from a NHRA stocker 340 and I will do it if it works out. Never done one before. Done 383's and bigger stuff.,never a 340. Been wanting to do one for a while.
Hope it works out. Reming me and I will post some pics if I do them.
And by the way, 900HP said it right, you do the swedging on the bottom, never the top. This is called blacksmithing. You have to shape the tube as much as possible by hand to fit the irregular shapes on the top and sides and blacksmith the floor down to the flange if the tube is being enlarged. I will have to lay all that out in my blog some time soon.
This also means you have to fit each tube from each port exactly where you want it to go. Most folks make all the tubes, weld them up and weld them into the flange last. I make the tube off the head right where it needs to be and finish the tube to flange fabing and welding. Then I finish each tube the rest of the way to collector. When you realize the power/flow is most important at the port/header transition, how can you do that last. You usually do not get things good enough.
Here is a shot of a 383 in a 62, sort of the same issues. They are actually 1 5/8" off the head.
You can see the step to 1.3/4 about 8" out from the head.
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Calvin Elston
Elston Exhaust
Matthews, NC 28104
346-704-4430
Blog: www.exhausting101.com
Elston Exhaust
Matthews, NC 28104
346-704-4430
Blog: www.exhausting101.com
Re: 340 Chrysler Street Header Questions
Calvin. I appreciate the feedback and the photos of the 383. Those look nice and you got everything moving down pretty early. The B/RB engines have a lot going for them other than the initial weight and size. I think the exit ports on the smallblock heads are bit lower in the chassis than the 383s but not much. I believe in '62 the Dart name was for a mid-size chassi and the compact was the Lancer. Then from '63 until '76 Darts were compacts. The tightest Dart engine compartments are '63, followed by '64-66. I hope you get to do the 340.
The credit goes to Brian Slowe - its his workmanship and design. He did try tack a 1.5" tube to a flange port but he wasnt comfortable blacksmithing the amount needed. I have to respect the limits he feels comfortable with on my dime. Instead we had these custom flanges made to handle the transition from the heads to the 1.5" tubing. I had some extras made, although the number of people interested in 1.5" primaries seems to be quite limited.
Our step up from 1.5 to 1.625" is at 9.5" if I recall correctly. Funny the step does look much further out on our header than on the 383 headers you made. Not sure if that's due to camara angles or measuring method.
- Matt
The credit goes to Brian Slowe - its his workmanship and design. He did try tack a 1.5" tube to a flange port but he wasnt comfortable blacksmithing the amount needed. I have to respect the limits he feels comfortable with on my dime. Instead we had these custom flanges made to handle the transition from the heads to the 1.5" tubing. I had some extras made, although the number of people interested in 1.5" primaries seems to be quite limited.
Our step up from 1.5 to 1.625" is at 9.5" if I recall correctly. Funny the step does look much further out on our header than on the 383 headers you made. Not sure if that's due to camara angles or measuring method.
- Matt
Re: 340 Chrysler Street Header Questions
A bit of progress.
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Re: 340 Chrysler Street Header Questions
I just recently took a close look at a stock 340 head and the exhaust ports. I noticed a big core shift issue.
Which means the machining of the bolt holes is not centered on the ports themselves.
On the head I was measuring the shift was as much as .080", ports being offset to the right in the bolt pattern.This makes it difficult to
keep the port area to size on the port if the heads are all different. If I have to allow for a possible shift of say .080 in both directions
and make the flange large enough to cover both possible offsets, a lot of velocity is lost as the tube and area is stretched further than it should be.
It is very discouraging to me. The effort then needs to focus on do we make the headers for the given set of heads or leave that power on the table? The obvious drawback is the headers are made for that set of heads and would loose power if used on a set of heads with a different coreshift location.
This was not uncommon in Winston Cup back in the early 90's as just about every engine had changed port configurations and sizes. Many times each engine had its own headers.
A bit over the top for a NHRA Stock engine? ...well, here we go...
If you are one who doesn't believe this stuff is important, well just move on, nothing here to see...
Which means the machining of the bolt holes is not centered on the ports themselves.
On the head I was measuring the shift was as much as .080", ports being offset to the right in the bolt pattern.This makes it difficult to
keep the port area to size on the port if the heads are all different. If I have to allow for a possible shift of say .080 in both directions
and make the flange large enough to cover both possible offsets, a lot of velocity is lost as the tube and area is stretched further than it should be.
It is very discouraging to me. The effort then needs to focus on do we make the headers for the given set of heads or leave that power on the table? The obvious drawback is the headers are made for that set of heads and would loose power if used on a set of heads with a different coreshift location.
This was not uncommon in Winston Cup back in the early 90's as just about every engine had changed port configurations and sizes. Many times each engine had its own headers.
A bit over the top for a NHRA Stock engine? ...well, here we go...
If you are one who doesn't believe this stuff is important, well just move on, nothing here to see...
Calvin Elston
Elston Exhaust
Matthews, NC 28104
346-704-4430
Blog: www.exhausting101.com
Elston Exhaust
Matthews, NC 28104
346-704-4430
Blog: www.exhausting101.com
Re: 340 Chrysler Street Header Questions
Calvin,
That parallels what we found with the mounting holes and since you pointed this out I will check the relationship with the ports. The exhaust mounting bolt pattern on the heads varied enough that if the flanges had been kept whole, they wouldn't bolt up to all 4 heads on hand. The mass produced flanges we looked at had a lot of slop. More than the factory castings it seemed! The flanges from Stainless had slotted outer mounting holes, which perhaps is a better approach but obviously we didn't think that was good enough.
The casting shift issue and its implication on the intake side apparently has been recognized by some racers for some time.
posted by Oldmanmopar on ForAbodiesOnly with credit to Roland Leong and Mike Dunn
"The most common problem on all intakes ...is left bank to right bank.... Scribe a line on the top of each intake port separator using a straight edge on the gasket side. Doing this will show you where the web between the two ports are after the intake is set in place. These lines should match centered with the valve cover bolt holes which are centered in the ports.
Wait until you all see how far off some of your intakes are. This is corrected by splitting the difference from side to side by moving the intake front or back. One reason after market intakes do not have the pin holes drilled. After you locate your intake put your pins back in and reset the intake back on in the corrected location."
That parallels what we found with the mounting holes and since you pointed this out I will check the relationship with the ports. The exhaust mounting bolt pattern on the heads varied enough that if the flanges had been kept whole, they wouldn't bolt up to all 4 heads on hand. The mass produced flanges we looked at had a lot of slop. More than the factory castings it seemed! The flanges from Stainless had slotted outer mounting holes, which perhaps is a better approach but obviously we didn't think that was good enough.
The casting shift issue and its implication on the intake side apparently has been recognized by some racers for some time.
posted by Oldmanmopar on ForAbodiesOnly with credit to Roland Leong and Mike Dunn
"The most common problem on all intakes ...is left bank to right bank.... Scribe a line on the top of each intake port separator using a straight edge on the gasket side. Doing this will show you where the web between the two ports are after the intake is set in place. These lines should match centered with the valve cover bolt holes which are centered in the ports.
Wait until you all see how far off some of your intakes are. This is corrected by splitting the difference from side to side by moving the intake front or back. One reason after market intakes do not have the pin holes drilled. After you locate your intake put your pins back in and reset the intake back on in the corrected location."
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Re: 340 Chrysler Street Header Questions
When designing a street header for an OEM type chassis/body it is usually the preferred criteria to make it fit FIRST ... only then to get the tube dimensions near where they should be best tuned; especially with a closed exhaust system. A LOT of compromises are usually made to benefit the fitment part.
Many custom header companies prefer to try and convey to a customer that a tri-Y set-up MAY make the best compromise, largely because of this.
Many custom header companies prefer to try and convey to a customer that a tri-Y set-up MAY make the best compromise, largely because of this.
http://www.rmcompetition.com
Specialty engine building at its finest.
Specialty engine building at its finest.
Re: 340 Chrysler Street Header Questions
This is a head that was sent too me for figuring a flange. You can see the .08" offset from "square".
We have checked other heads and found no offset.
The flange for this job will have .100" added to the left side of each port opening to allow for .080" to center plus another .020 for an offset to the other side.
Only the center ports flange is one piece. The end ports are individual.
We have checked other heads and found no offset.
The flange for this job will have .100" added to the left side of each port opening to allow for .080" to center plus another .020 for an offset to the other side.
Only the center ports flange is one piece. The end ports are individual.
You do not have the required permissions to view the files attached to this post.
Calvin Elston
Elston Exhaust
Matthews, NC 28104
346-704-4430
Blog: www.exhausting101.com
Elston Exhaust
Matthews, NC 28104
346-704-4430
Blog: www.exhausting101.com
Re: 340 Chrysler Street Header Questions
Are you saying the 6 exhaust manifold bolt pattern is not consistent in itself from head to head? A one piece flange will not consistently bolt up?Mattax wrote:Calvin,
That parallels what we found with the mounting holes and since you pointed this out I will check the relationship with the ports. The exhaust mounting bolt pattern on the heads varied enough that if the flanges had been kept whole, they wouldn't bolt up to all 4 heads on hand. The mass produced flanges we looked at had a lot of slop. More than the factory castings it seemed! The flanges from Stainless had slotted outer mounting holes, which perhaps is a better approach but obviously we didn't think that was good enough.
The casting shift issue and its implication on the intake side apparently has been recognized by some racers for some time.
posted by Oldmanmopar on ForAbodiesOnly with credit to Roland Leong and Mike Dunn
"The most common problem on all intakes ...is left bank to right bank.... Scribe a line on the top of each intake port separator using a straight edge on the gasket side. Doing this will show you where the web between the two ports are after the intake is set in place. These lines should match centered with the valve cover bolt holes which are centered in the ports.
Wait until you all see how far off some of your intakes are. This is corrected by splitting the difference from side to side by moving the intake front or back. One reason after market intakes do not have the pin holes drilled. After you locate your intake put your pins back in and reset the intake back on in the corrected location."
Good grief. I don't think GM or Ford stuff is like that, but I never use one piece flanges so I don't have much knowledge here. I would have thought the manufacturers would of at least used gang drilling machines for this stuff...?
Calvin Elston
Elston Exhaust
Matthews, NC 28104
346-704-4430
Blog: www.exhausting101.com
Elston Exhaust
Matthews, NC 28104
346-704-4430
Blog: www.exhausting101.com
Re: 340 Chrysler Street Header Questions
Yes - at least that's what we are finding from the two pairs I have, and also by inference. I think the pairs were consistant, but even that I'm not sure of - I can check on Monday. One set was manufactured in '73 (340) and the other set in '78 (360) and later machined for the 340 valves.Are you saying the 6 exhaust manifold bolt pattern is not consistent in itself from head to head? A one piece flange will not consistently bolt up?
We had our flanges drilled with mounting holes .320" max and then found they did not fit my other heads. I *think* the problem was just one of the ports - I can check too that on Monday. editBottom line - best to ask your customer to measure the other head!
Here's a couple photos showing the Stainless Headers Company flange with the slots. Slots are approximately 0.44" x .32". I forget whose steel flange is in the foreground but the holes are 0.380" diameter.
Maybe this also explains why the mass produced headers all start with 1 5/8" tubing - its probably the only way to be somewhat sure their headers don't step into the flow (and the 273- 318 market is too small to bother with).
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Re: 340 Chrysler Street Header Questions
Well, the port area is really close to the area of a 1.63OD tube at 18ga...and I doubt any massed producer of headers cares much about those issues. The shape of the 340 port is a hard one to deal with for mass producers, period. Add in what I call severe core/machining offset and things are in the toilet in a hurry. Job security...Mattax wrote: Maybe this also explains why the mass produced headers all start with 1 5/8" tubing - its probably the only way to be somewhat sure their headers don't step into the flow (and the 273- 318 market is too small to bother with).
Calvin Elston
Elston Exhaust
Matthews, NC 28104
346-704-4430
Blog: www.exhausting101.com
Elston Exhaust
Matthews, NC 28104
346-704-4430
Blog: www.exhausting101.com
Re: 340 Chrysler Street Header Questions
I suspect those were cleaned up - maybe matched to a gasket? The one set I have that appears untouched has port areas as follows
1.50 sq in
1.53 sq in
1.59 sq in
1.47 Sq in
The set that I suspect was gasket matched is
1.75 sq in
1.78 sq in
1.78 sq in
1.78 sq in
(counting squares method)
1.50 sq in
1.53 sq in
1.59 sq in
1.47 Sq in
The set that I suspect was gasket matched is
1.75 sq in
1.78 sq in
1.78 sq in
1.78 sq in
(counting squares method)