We are currently running on the new domain and server: www.Speed-Talk.com

IMPORTANT: Update your bookmarks to https://www.speed-talk.com/forum/
(Right-click the URL and select "Bookmark this link")

BBC tunnel ram

General engine tech -- Drag Racing to Circle Track

Moderator: Team

Post Reply
prairiehotrodder
Guru
Guru
Posts: 1033
Joined: Sat Dec 24, 2011 10:02 am
Location: melfort saskatchewan Canada

BBC tunnel ram

Post by prairiehotrodder » Tue Oct 29, 2019 3:11 pm

have you dyno tested the Edelbrock #7085 tunnel ram against any other tunnel rams ? I'm using the old Weiand #1985 rectangle port and i read somewhere that Edelbrock claims their new version (made in 2013) #7085 is worth 40 - 50 hp over other t-rams (didn't say which ones). This is all pretty vague so i thought i'd ask the speed talk world. One thing i don't like about the 7085 is it only has a top for dominators. I'm liking my 4150 base 750 carbs even though i would like to try bigger carbs. Maybe 850 or 950 but not ready to make the jump to dominators. I'd have to use adapters or build my own top to run 4150 carbs on the 7085 edelbrock.
Brian

Edit : they claim it made 47 hp over the old victor 2-R and 10 hp over the competition. So i guess it depends which "competition" intakes they were talking about.
The Word of God is quick and powerfull
www.therocketshop.blogspot.com

SchmidtMotorWorks
Vendor
Posts: 10124
Joined: Mon Apr 11, 2005 2:30 am
Location:
Contact:

Re: BBC tunnel ram

Post by SchmidtMotorWorks » Tue Oct 29, 2019 4:11 pm

It depends on your application.
Take a look at the Profiler manifold.
http://www.schmidtmotorworks.com Prototypes, Tooling, Molds.

F-BIRD'88
Guru
Guru
Posts: 7278
Joined: Tue Mar 27, 2007 6:56 pm
Location: Ontario, Canada

Re: BBC tunnel ram

Post by F-BIRD'88 » Tue Oct 29, 2019 9:41 pm

If you think that your carbs are too small try adding plenum volume and carb height.
( carb spacers) You could also build your own custom plenum for your current Weiand tunnel ram.

F-BIRD'88
Guru
Guru
Posts: 7278
Joined: Tue Mar 27, 2007 6:56 pm
Location: Ontario, Canada

Re: BBC tunnel ram

Post by F-BIRD'88 » Tue Oct 29, 2019 9:46 pm

Joe Sherman was a expert at this stuff.. With the big full race tunnel rams he really spin the engines up high to get the power gain. Not sure you want to go there. Takes top parts and maintenance to go there.
$$$$

WeingartnerRacing
Expert
Expert
Posts: 654
Joined: Sun Dec 14, 2008 8:37 pm
Location: Broken Arrow, Oklahoma
Contact:

Re: BBC tunnel ram

Post by WeingartnerRacing » Tue Oct 29, 2019 11:49 pm

I used one on my 565bbc it made 1118hp@7500rpm
You do not have the required permissions to view the files attached to this post.
Eric Weingartner
Weingartner Racing LLC
918-520-3480
www.wengines.com

Old School
Pro
Pro
Posts: 381
Joined: Sun Feb 13, 2005 11:27 am
Location:

Re: BBC tunnel ram

Post by Old School » Wed Oct 30, 2019 10:01 am

WeingartnerRacing wrote:
Tue Oct 29, 2019 11:49 pm
I used one on my 565bbc it made 1118hp@7500rpm
Do you have any et -mph on the on the car with the 565? Very nice engine.

WeingartnerRacing
Expert
Expert
Posts: 654
Joined: Sun Dec 14, 2008 8:37 pm
Location: Broken Arrow, Oklahoma
Contact:

Re: BBC tunnel ram

Post by WeingartnerRacing » Wed Oct 30, 2019 10:06 am

Old School wrote:
Wed Oct 30, 2019 10:01 am
WeingartnerRacing wrote:
Tue Oct 29, 2019 11:49 pm
I used one on my 565bbc it made 1118hp@7500rpm
Do you have any et -mph on the on the car with the 565? Very nice engine.
Not yet still finishing it. Driveshaft should be here today. Hopefully in March.
Eric Weingartner
Weingartner Racing LLC
918-520-3480
www.wengines.com

Old School
Pro
Pro
Posts: 381
Joined: Sun Feb 13, 2005 11:27 am
Location:

Re: BBC tunnel ram

Post by Old School » Wed Oct 30, 2019 2:05 pm

WeingartnerRacing wrote:
Wed Oct 30, 2019 10:06 am
Old School wrote:
Wed Oct 30, 2019 10:01 am
WeingartnerRacing wrote:
Tue Oct 29, 2019 11:49 pm
I used one on my 565bbc it made 1118hp@7500rpm
Do you have any et -mph on the on the car with the 565? Very nice engine.
Not yet still finishing it. Driveshaft should be here today. Hopefully in March.
Thanks

engineguyBill
HotPass
HotPass
Posts: 1099
Joined: Fri Feb 26, 2010 11:15 am
Location: Gold Canyon, AZ

Re: BBC tunnel ram

Post by engineguyBill » Sat Nov 02, 2019 2:23 pm

As far as cast tunnel rams are concerned, I have had excellent results with the Dart product.
Bill

SAE Member (29+ years)
ASE Master Certified Engine Machinist (+ two otherASE Master Certifications)
AERA Certified Professional Engine Machinist

"Do what you can, with what you have, where you are."
- Theodore Roosevelt

prairiehotrodder
Guru
Guru
Posts: 1033
Joined: Sat Dec 24, 2011 10:02 am
Location: melfort saskatchewan Canada

Re: BBC tunnel ram

Post by prairiehotrodder » Mon Nov 18, 2019 9:50 am

all other things being equal, what does adding plenum volume to the intake manifold do for an engine ?

Brian
The Word of God is quick and powerfull
www.therocketshop.blogspot.com

F-BIRD'88
Guru
Guru
Posts: 7278
Joined: Tue Mar 27, 2007 6:56 pm
Location: Ontario, Canada

Re: BBC tunnel ram

Post by F-BIRD'88 » Mon Nov 18, 2019 3:59 pm

A larger plenum will slow the air draw speed on each carb venturi. It will tend to dampen induction pulse force both coming and going . Each cylinders intake port has a larger volume of air/fuel to draw from on each intake stroke.

sort of like the action of a shock absorber dampening a spring. Sort of like a condenser's effect action on a AC electrical circuit.

The engine can breathe deeper at high rpm if the carbs are on the small side relative to cid- power demand.

A wider plenum cross section has a slightly diffrrent effect
than a taller plenum cross section does. (Carb height above runner entries.)

Plan on carb re jetting (most likely bigger main jets if plenum volume is added.

Post Reply