Click here to visit The FieroStore | View all sponsors
  Pennock's Fiero Forum
  Technical Discussion & Questions
  The Turbo 3500 F23 swap (Page 12)

Post New Topic  Post A Reply
Email This Page to Someone! | Printable Version

This topic is 12 pages long:  1   2   3   4   5   6   7   8   9   10   11   12 
Previous Page | Next Page
next newest topic | next oldest topic
The Turbo 3500 F23 swap by ericjon262
Started on: 10-03-2011 11:26 PM
Replies: 453 (19604 views)
Last post by: ericjon262 on 11-12-2019 07:53 PM
Will
Member

Posts: 12963
From: Where you least expect me
Registered: Jun 2000


Feedback score: (1)
Leave feedback





Total ratings: 234
Rate this member

Report this Post10-28-2019 12:01 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post

The length of the runners has *MUCH* more impact on that phenomenon.

IP: Logged

pmbrunelle
Member

Posts: 3047
From: Grand-Mère, Québec
Registered: Sep 2008


Feedback score: N/A
Leave feedback





Total ratings: 55
Rate this member

Report this Post10-28-2019 06:01 PM Click Here to See the Profile for pmbrunelleClick Here to Email pmbrunelleSend a Private Message to pmbrunelleEdit/Delete MessageReply w/QuoteDirect Link to This Post

 
quote
Originally posted by Will:

The length of the runners has *MUCH* more impact on that phenomenon.


Yes, flexibility drastically increases with runner length. But since Eric showed us a picture of pieces of metal already starting to look like a short-runner log manifold, it looked like that aspect of the design was already "frozen", so I didn't mention it.

The desire for flexibility is what led me towards the sledgehammer approach whereby I installed bellows between the ports of my stock 2.8 log manifolds.

[This message has been edited by pmbrunelle (edited 10-28-2019).]

IP: Logged

ericjon262
Member

Posts: 2452
From: everywhere.
Registered: Jan 2010


Feedback score:    (10)
Leave feedback





Total ratings: 62
Rate this member

Report this Post10-28-2019 08:09 PM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post

 
quote
Originally posted by pmbrunelle:
Another possible advantage of the metal connecting strip occurred to me.

As the log manifold heats up (I'm really talking about the tapered slit tube), it will grow lengthwise. The cylinder head on the other hand, having a much smaller temperature rise, will maintain a relatively constant length.

The length mismatch that will occur between the parts may be resolved by consequences such as shearing the bolts, or sliding on the gaskets.

If your log manifold has a connecting strip that remains relatively cool, it will force the distance between the ports to remain more constant.
However, there will be more stress within the manifold itself.


sliding on the gaskets is ok to some degree, shearing bolts is not, one of the details I had not yet discussed here, was that I intended to have to bolt holes at the center port round, and the bolt holes at the outer port slightly slotted lengthwise to alleviate some of the expansion stress.

My biggest concern, is that with the short runner length and long log, is that crack may form at the junction between the flange and the runner.

 
quote
Originally posted by Will:

The length of the runners has *MUCH* more impact on that phenomenon.


Agreed, because the stress is no longer applied in whole to the flange, it is now applied across both the runners, and the flange.

 
quote
Originally posted by pmbrunelle:
Yes, flexibility drastically increases with runner length. But since Eric showed us a picture of pieces of metal already starting to look like a short-runner log manifold, it looked like that aspect of the design was already "frozen", so I didn't mention it.

The desire for flexibility is what led me towards the sledgehammer approach whereby I installed bellows between the ports of my stock 2.8 log manifolds.


I have yet to calculate the difference in expansion between the two parts, but I think a bellows between the ports may be way overkill. it's also a huge efficiency killer, those bellows are a huge amount of surface area, having more than one pre-turbo is a band-aid for bad engineering IMO.

I have enough material to lengthen the runners, but I want to keep them as tight to the head as I can, it will make maintenance easier, and improve overall efficiency.

------------------
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

"The day I tried to live, I stole a thousand beggars' change and gave it to the rich."
http://www.fiero.nl/forum/Forum2/HTML/119122.html

IP: Logged

ericjon262
Member

Posts: 2452
From: everywhere.
Registered: Jan 2010


Feedback score:    (10)
Leave feedback





Total ratings: 62
Rate this member

Report this Post10-28-2019 10:09 PM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post

https://www.engineeringtool...ion-pipes-d_283.html

according to this, over about 12"(approximate length of the log) of pipe, and a temperature difference of around 1300F from installed state to what is probably well over max operating temperature yields an expansion of about 0.2" similar math for the head, assuming 142F rise (due to coolant) results in an expansion of 0.022", a difference in expansion of .178"

using the difference in temperature for the head, and the expansion of the stainless gives us an expansion of.019 for the flange, a difference of .003 between the head and flange, if I were a betting man, I would say that the flange is probably slightly hotter than the head, due to the lower thermal conductivity of stainless compared to aluminum, and the lack of cooling medium.

knowing this, across the entire head, I have a difference of about .18" between the log and the flange. that I need to make up. but the force on the runners will be applied bidirectionally, with about .126" of expansion between the ports further apart, and about .054 between the ports close together.

All of this is assuming steady state temperature, I imagine transient dT's would be lower.

.156" pipe
.0195" head
.0167" flange
.098" wide
.042" narrow

on the front bank, most of the expansion can be taken up by the bend from the first port. as it should be relatively free to expand towards front passenger side of the engine compartment, on the rear bank, that expansion has to be taken between the ports, as both ports will discharge at almost right angles to the pipe. short of building a 3-1 header style manifold, I don't think there's much I can do there, slotting the boltholes at the ends of the flange would allow the pipe to move the flange to a small degree, but it will also be forced counter to that by it's lesser expansion, and would have to also fight the force applied by the tension of the bolts also resisting flange movement. the angular displacement between the flange and the pipe based on these measurements is approximately 4.1-5.2 degrees.

Edit to add, I may re-do the math later with a higher flange temperature to see how those changes affect, this math currently assumes flange temperature is very close to head temperature, looking at the actual thermal conductivity of stainless and cast aluminum, I think it's safe to say the flange would be significantly hotter, which would cause an increase in shear load on the bolts, as well as reduced displacement between the flange and log.

[This message has been edited by ericjon262 (edited 10-29-2019).]

IP: Logged

pmbrunelle
Member

Posts: 3047
From: Grand-Mère, Québec
Registered: Sep 2008


Feedback score: N/A
Leave feedback





Total ratings: 55
Rate this member

Report this Post10-29-2019 09:46 PM Click Here to See the Profile for pmbrunelleClick Here to Email pmbrunelleSend a Private Message to pmbrunelleEdit/Delete MessageReply w/QuoteDirect Link to This Post

Do note that the way you're calculating thermal growth of the log assumes that the manifold is free to grow "as the part wants".

The log probably won't grow as much as predicted by the delta_temp*expansion_coefficient*initial_length formula, because the runners (which are attached to the massive stiff head) will force the log to remain shorter than it would otherwise be if left unrestrained.

Actually, the stress in the metal arises because the log is being "compressed shorter".

If you wanted to evaluate the risk of the metal cracking, the end-goal of this math/calculations could to estimate the stress in the metal at different key points in the manifold.

********************************************************************************

Here's an idea I have for an rough stress test that requires minimal tools/equipment:

1. After fabrication, cut away the connecting strip from the flange.
2. Place the completed manifold vertically in a hydraulic press.
3. Squish the two ends ports towards each other by .150", or whatever number you feel is representative of the length mismatch in service.
4. Check if the manifold has been plastically deformed. Before/after measurements may be helpful.

If you've plastically deformed your manifold, well at least you did it on the bench, rather than on the car which may entail dropping the cradle and all that...

IP: Logged

ericjon262
Member

Posts: 2452
From: everywhere.
Registered: Jan 2010


Feedback score:    (10)
Leave feedback





Total ratings: 62
Rate this member

Report this Post10-29-2019 10:59 PM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post

 
quote
Originally posted by pmbrunelle:

Do note that the way you're calculating thermal growth of the log assumes that the manifold is free to grow "as the part wants".

The log probably won't grow as much as predicted by the delta_temp*expansion_coefficient*initial_length formula, because the runners (which are attached to the massive stiff head) will force the log to remain shorter than it would otherwise be if left unrestrained.

Actually, the stress in the metal arises because the log is being "compressed shorter".

If you wanted to evaluate the risk of the metal cracking, the end-goal of this math/calculations could to estimate the stress in the metal at different key points in the manifold.


which is why I also calculated the expansion of the head, in the operating temperatures the components will see, the thermal expansion of the aluminum head is actually higher than that of the stainless flange.


 
quote
Originally posted by pmbrunelle:
Here's an idea I have for an rough stress test that requires minimal tools/equipment:

1. After fabrication, cut away the connecting strip from the flange.
2. Place the completed manifold vertically in a hydraulic press.
3. Squish the two ends ports towards each other by .150", or whatever number you feel is representative of the length mismatch in service.
4. Check if the manifold has been plastically deformed. Before/after measurements may be helpful.

If you've plastically deformed your manifold, well at least you did it on the bench, rather than on the car which may entail dropping the cradle and all that...


this test would be in no way representative of actual operating conditions, the results of said test wouldn't really tell me much.

I did realize a mistake in my math I split the length for the pipe, but not the flange, resulting in larger than actual divergence. I also re-did the math for for a higher flange temperature


0.0195" head

0.0167" flange
0.01169"  wide
0.00501" narrow

0.156" pipe
0.098" wide
0.042" narrow


0.071" flange hot
0.0497" wide
0.0213" narrow

difference warm
0.0864 wide
0.0369 narrow

divergence warm
3.62 degrees wide
1.57 degrees narrow

difference hot
0.0483" wide
0.0217" narrow

divergence hot
2.049 degrees wide
0.92 degrees narrow

I feel like hot stainless should be able to handle that much without problem, I also plan on having the manifolds coated which help thermally as well.

------------------
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

"The day I tried to live, I stole a thousand beggars' change and gave it to the rich."
http://www.fiero.nl/forum/Forum2/HTML/119122.html

IP: Logged

ericjon262
Member

Posts: 2452
From: everywhere.
Registered: Jan 2010


Feedback score:    (10)
Leave feedback





Total ratings: 62
Rate this member

Report this Post11-01-2019 09:10 PM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post



first ever attempts at welding stainless steel. I can tell already I need lots of practice. I think my travel speed is too slow, and I probably should have spent more time prepping the surfaces, I'm planning on picking up some stainless wire wheels tomorrow, and I'll use them to brush the weld areas, and then I'll wipe them, as well as the filler, with acetone prior to welding. I'm also going to use solarflux on the back of the weld to prevent pickling the backsides.

------------------
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

"The day I tried to live, I stole a thousand beggars' change and gave it to the rich."
http://www.fiero.nl/forum/Forum2/HTML/119122.html

IP: Logged

pmbrunelle
Member

Posts: 3047
From: Grand-Mère, Québec
Registered: Sep 2008


Feedback score: N/A
Leave feedback





Total ratings: 55
Rate this member

Report this Post11-01-2019 10:20 PM Click Here to See the Profile for pmbrunelleClick Here to Email pmbrunelleSend a Private Message to pmbrunelleEdit/Delete MessageReply w/QuoteDirect Link to This Post

Is that TIG?

IP: Logged

ericjon262
Member

Posts: 2452
From: everywhere.
Registered: Jan 2010


Feedback score:    (10)
Leave feedback





Total ratings: 62
Rate this member

Report this Post11-01-2019 11:08 PM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post

 
quote
Originally posted by pmbrunelle:

Is that TIG?


yes, but very poorly executed. I think my current was a bit high, and my travel speed a bit low. I've done a couple more runs, and they look a little better, but I still need more practice.

------------------
"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

"The day I tried to live, I stole a thousand beggars' change and gave it to the rich."
http://www.fiero.nl/forum/Forum2/HTML/119122.html

IP: Logged

ericjon262
Member

Posts: 2452
From: everywhere.
Registered: Jan 2010


Feedback score:    (10)
Leave feedback





Total ratings: 62
Rate this member

Report this Post11-03-2019 01:32 PM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post

a little less stickout, a litttle more prep, a little more speed, and a little less current netted this:



much better, but I still need more practice.

IP: Logged

ericjon262
Member

Posts: 2452
From: everywhere.
Registered: Jan 2010


Feedback score:    (10)
Leave feedback





Total ratings: 62
Rate this member

Report this Post11-07-2019 12:55 AM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post

Practice helps, alot!



old on the left, new on the right. still a bit hot, but way better!



One log and runner are assembled, unfortunately, I can't really make any more progress until I get the new flanges made. tomorrow, when I get off work I plan to triple check all of my measurements and find someone to cut them ASAP. my fabrication plan is to tack weld the 45's to the flange, and then set the log on top and trim both until I have a proper fit, then weld everything up.

IP: Logged

ericjon262
Member

Posts: 2452
From: everywhere.
Registered: Jan 2010


Feedback score:    (10)
Leave feedback





Total ratings: 62
Rate this member

Report this Post11-11-2019 09:01 PM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post

I've spent the past few days hammering out the flange for the new turbo manifold, I'm pretty sure I've got it spot on, now. I've had it 3d printed twice, and I think I'm already approaching the point of diminishing returns.



This images is larger than 153600 bytes. Click to view.

The final step before the laser will be a thin sheet metal "flange", as my friend's 3D printer wasn't exactly accurate for the hole sizes. once it's "proved", I'll have them cut in at lead 3/8" 304 SS and get hot on finishing them up.

IP: Logged

pmbrunelle
Member

Posts: 3047
From: Grand-Mère, Québec
Registered: Sep 2008


Feedback score: N/A
Leave feedback





Total ratings: 55
Rate this member

Report this Post11-12-2019 12:34 PM Click Here to See the Profile for pmbrunelleClick Here to Email pmbrunelleSend a Private Message to pmbrunelleEdit/Delete MessageReply w/QuoteDirect Link to This Post

How are you going to change from D-shaped to round?

IP: Logged

ericjon262
Member

Posts: 2452
From: everywhere.
Registered: Jan 2010


Feedback score:    (10)
Leave feedback





Total ratings: 62
Rate this member

Report this Post11-12-2019 07:53 PM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post

I'll carefully form the pipe to the port. a few tack welds, a little heat, and some caressing. and it'll be a nice transition.

IP: Logged

Previous Page | Next Page

This topic is 12 pages long:  1   2   3   4   5   6   7   8   9   10   11   12 
next newest topic | next oldest topic

All times are ET (US)

Post New Topic  Post A Reply
Hop to:

Contact Us | Back To Main Page

Advertizing on PFF | Fiero Parts Vendors
PFF Merchandise | Fiero Gallery | Ogre's Cave
Real-Time Chat | Fiero Related Auctions on eBay



Copyright (c) 1999, C. Pennock