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390 Crossram SRT-11

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one bad rambler View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote one bad rambler Quote  Post ReplyReply Direct Link To This Post Posted: Feb/03/2019 at 5:50pm
Originally posted by ccowx ccowx wrote:

Check this out: http://www.theamcforum.com/forum/measured-plenum-volumes-of-all-amc-intakes_topic96180_page1.html?KW=intake+volume

Here is the chart giving some idea of the relative volumes. Note that the STR-11 is actually about 50% larger in volume than a UR-18. Just because a carb is set up for tunell rams does not mean that it will work perfectly with a cross ram. 

Dual Planes


Edelbrock SP2P (66-69 version)                     1.5 Liters  (6.4 cups)


Edelbrock Performer #2131                          2.5 Liters (10.5 cups)


Performer RPM #7581 Air Gap                        2.6 Liters (11 cups)

 
Edelbrock R4B 1970+                                          4.0 Liters (17 cups)





Single planes:


Edelbrock Torker #3930                                   2.72 Liters (11.5 cups)


Offy Dual Quad with 1/2" spacers                           3.8 Liters (16 cups) 


HLR High rise intake (ported)                                      3.9 Liters (16.5 cups) 


Edelbrock UR-18 with UR-11 Dominator top       5.32 Liters (22.5 cups)


Edelbrock UR-18 with Weiand 1911 top             5.55 Liters (23.5 cups)


Edelbrock (original) STR-11 70' up Crossram     9.32 Liters (39 cups!)


 




^^^^^^these intakes were volume tested at roughly a junior high school level of accuracy (maybe).
I duct taped the ports, made a bolt on end plate to keep most of the water in, and filled them with measuring cups.
Test was run twice on each intake, so it should be pretty accurate.

All intakes are as cast/not ported (except for the HLR intake).


I ran mine on the street with 10.4: compression and the old Group 19 camshaft. It ran ok, though you could feel that it was struggling to keep up at lower rpms. It did feel good at high rpms though!

Chris 
are there any dyno tests between the air gap and the r4b?...I run a UR 18 and the cars due require some tuning to say the least...I run 600 DP
68 AMX 390 4 Speed,68 American,64 American 2 Door Wagon Altered Wheelbase,78 Concord Build 360,727,8.8
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ramzilla Quote  Post ReplyReply Direct Link To This Post Posted: Feb/05/2019 at 6:52pm
Did some more searching on the Holley Performance site. I know some run 4776 Holley's. Holley has a carb called Brawler 4150 600cfm or 650cfm both carbs run about the same jets and pump nozzle size. They are also mechanical double pumpers like the 4776. Also you can get rods to adjust the secondaries to come in at 60 or 40 percent of Primaries opening. With the option of that adjustment you could run on the front butterflies till a certain rpm. Then the opening of the secondaries would be at the right rpm hopefully to take advantage of the extra fuel. I know in my SC Rambler I could run on the front butterflies with my carter
to about 90 or 95 before the secondaries would come. I think the cam I will be using is Crane Hydraulic roller HR-224/339-2s-12 2000-6000 power range. Roller rockers. Doug Headers would like to build a 3" not sure if it will fit. I have my original 2" I can use as pattern. Would like to use kt pistons and rods. Still not sure about Heads I know I will need to cut valve seat and an if I use mine stainless steel valves. Also I think I will need to have some head work done or all the other improvements will be wasted. Maybe edelbrock heads. $$$ Open to any and all suggestions. Thanks Larry
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ramzilla Quote  Post ReplyReply Direct Link To This Post Posted: Feb/05/2019 at 6:58pm
Forgot Brawler carbs are for STR-11 crossram.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ccowx Quote  Post ReplyReply Direct Link To This Post Posted: Feb/05/2019 at 7:46pm
Why would you put a 3" system on? That is way overkill for what you need and will cost you a bit of mid range torque. I would think that 2-1/2" will do fine and I doubt you can get 3" easily over the axle for stock exits. I do like your idea of aluminum heads, it will allow you to bump the compression a bit, which will help with that manifold. 

Chris 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ramzilla Quote  Post ReplyReply Direct Link To This Post Posted: Feb/05/2019 at 8:10pm
Ok 2 1/2" it is thanks for response.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ramzilla Quote  Post ReplyReply Direct Link To This Post Posted: Mar/11/2019 at 11:31pm
Glennrock
A couple of questions on Doug Headers. For my SC Rambler Doug only lists D 109 1 5/8 inch primaries. Is there fitment issues with 1 3/4 & 1 7/8. Do you know what can be done if any to fit the larger dia. headers that are made for AMX. And will the ceramic headers run cooler. I am here in Arizona. Looks like Cal. is location of Doug products and Pertronix also. Looking into Pertronix ignition also. The new HP Moblie product. Thanks for any input Ramzilla
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Post Options Post Options   Thanks (0) Thanks(0)   Quote PROSTOCKTOM Quote  Post ReplyReply Direct Link To This Post Posted: Mar/12/2019 at 1:19am
Originally posted by Ramzilla Ramzilla wrote:

Glennrock
A couple of questions on Doug Headers. For my SC Rambler Doug only lists D 109 1 5/8 inch primaries. Is there fitment issues with 1 3/4 & 1 7/8. Do you know what can be done if any to fit the larger dia. headers that are made for AMX. And will the ceramic headers run cooler. I am here in Arizona. Looks like Cal. is location of Doug products and Pertronix also. Looking into Pertronix ignition also. The new HP Moblie product. Thanks for any input Ramzilla
If you want the best set of headers buy a set of all stainless steel American Racing Headers. Many members here have already purchased them and ARH actually used members cars to build the prototypes off of. Yes, they will cost a few dollars, but you only have to buy them one time,you can choose the size you want, and regardless of tubing size they all fit perfectly. http://americanracingheaders.com/collections/amc

Tom
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ramzilla Quote  Post ReplyReply Direct Link To This Post Posted: Jun/11/2019 at 8:19pm
[QUOTE=SC397]
I built a 401 a couple of years ago with a Crossram and was limited on compression ratio and cam.  Even with 9.5:1 compression ratio and a Comp 280H cam in it a pair of 600 Holleys were just right for it.  We had it on a dyno watching for a lean or rich condition and it never ran rich.

What was the carb number on those 600 Holleys. Also were they Double pumpers. Thanks Ramzilla
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Post Options Post Options   Thanks (0) Thanks(0)   Quote PHAT69AMX Quote  Post ReplyReply Direct Link To This Post Posted: Jun/18/2019 at 8:56pm
No endorsement, just stumbled across them...
A used freshly rebuilt pair of "newer" Holley List 9776 450 cfm Tunnel Ram Carburetors
for sale on FaceBook MarketPlace asking $500 for the pair in Chattanooga TN...
Very much like the original Hurst SS AMX 585 CFM Holley List 4584 Carbs on the CrossRam only smaller.
Thought no harm in passing on the info regardless...

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ramzilla Quote  Post ReplyReply Direct Link To This Post Posted: Jun/19/2019 at 6:10pm
Thanks Holley's look nice good price to. Carburation is still up in the air. Even thought about Fitach. Almost done with front suspension cleanup need to paint a couple of parts yet and install bushings in a couple of parts. No rust but dirty underneath wheel wells Just want to clean it up. Not painting body parts. Still need to remove engine. Than can remove crossmember to cleanup and paint before installing frontend parts. Maybe should of removed motor the first thing. O WELL Just did not want to see motor out just sitting there staring at me!!!     
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