Comparing Sheetmetal Tunnel Ram to cast single Four

so after looking at different manifolds for the c-heads , i saw a couple of fabricated Tunnel Rams with a single carb set up ...but i would think that the FRPP cast manifold would be a better piece ....it seems like the end runners on the Tunnel ram are so far away that they would cause a lean condition and that if you do go with a TR you would be better off going to a 2 carb deal ......... so what do you guys think

My little budies C headed deal just has the one carb and 3 foggers..........the carb is to drive it to the lanes, make the burnout, and drive back to the pits.............all them nozzels make the pass.

IMO single carb is simpler, cheaper, lighter. Dual carb will make a bit more power on motor, but not sure if its worth it with all the spray.

Back in the 60's....they said "with dope there is hope".....2009...."with spray there is a way"

richter69 wrote:My little budies C headed deal just has the one carb and 3 foggers..........the carb is to drive it to the lanes, make the burnout, and drive back to the pits.............all them nozzels make the pass.

IMO single carb is simpler, cheaper, lighter. Dual carb will make a bit more power on motor, but not sure if its worth it with all the spray.

tr or cast ?

You could buy Charlies C head to A head intake adapters. With a ported Trick Flow tunnel ram and adapters, you will be right about 1K, give or take a few bucks. Of course, then you'll need two carbs as well...

let me rephrase the question again ......... if the client wants to use a single carb and he has a choice between a tr and the cast manifold which is better ??........ to me the design of the cast manifold looks like it has better distribution and the single carb TR looks like it would have problem with fuel dist. on the corners.

what do you guys think .......

If I remember correctly, the A460 tunnel ram with the pent roof single four top was superior to the cast single four intake. Seems to me Charlie did some testing and I believe that was the case. The single four C 460 manifold is a nice piece though and might be the best choice for your deal, Nick. Doesn't require adapters and is certainly the cheaper route. I'm not a "juice" guy so, I tend to think two carbs and a tunnel ram. It's whatever you want, it just takes money

If you use 2 carbs, does that make it easier to adjust the "longer" runs so that they don't get lean?

With two carbs you can put 8 jets in it and "balance" A/F for each cylinder?

What do you think??

Bruce

Bsherry wrote:If you use 2 carbs, does that make it easier to adjust the "longer" runs so that they don't get lean?

With two carbs you can put 8 jets in it and "balance" A/F for each cylinder?

What do you think??

Bruce

Seems to be the case, in my experience. I'm considering splits on my new build to position the carbs for even better distribution. We shall see...

One reason I believe a sheetmetal TR will outperform a cast intake is harmonics (runner length). The sheetmetal TR will have equal runner lengths and runner lengths that are tuned for your exact engine combo. It's very similar to equal length headers...just on the intake side .

I'm going sheetmetal TR on my low RPM build. When I get it dynod, I expect to see reasonable gains over my 'tuning window'.

Have a good day!
Michael

I have not fooled with the tfs TR before, but i'd be intrested in how much CSA there is available at the runner entry in the plenum, or how big can it physically go before welding,ect ? runner lenghts would also be nice too.

Don't have exact dimensions, but I know the TFS tunnelram will port match to Charlies cnc'd C 460 heads.

so how much taller from the top of my carb now is it going to raise if i go with a sing carb tr ??

Your gonna need a big scoop Nick............

They are ok, driving through the pits kinda suck though, really got to pay attention as you can see anything on the other side of the thing lol.

RGL wrote:I have not fooled with the tfs TR before, but i'd be intrested in how much CSA there is available at the runner entry in the plenum, or how big can it physically go before welding,ect ? runner lenghts would also be nice too.

The new style TFS A-460 tunnel ram has really thick walls. Probally on the order of .250"+. I have never seen anybody have to weld the outside of the runners, in order to physically port them larger. I would say if a guy did have to weld the outside of the runners, then he probally screwed up somewhere in his porting efforts. It's a very good manifold, and on the old forum we saw where Frank Merkl made 1440? Hp with his 572 CID C-460 headed engine, my adapter plates, and the TFS A-460 tunnel ram intake maniold, on spray.

Hope this helps,

Charlie Evans

thanks Mr evans , i had never seen one in person , just wanted to know if it had enough meat in it to put 30%ish taper into the runner for some profilers , sounds like it might have it

RGL wrote:thanks Mr evans , i had never seen one in person , just wanted to know if it had enough meat in it to put 30%ish taper into the runner for some profilers , sounds like it might have it

Well, IMO a 30% taper is a little too much. I think Darin Morgan at ProFiler would agree with me on that. I have been encouraging both Darin and Micheal Greene at ProFiler to make a dedicated tunnel ram intake manifold for their Ford 205 heads. I've been doing it for about 1.5 years, and honestly they haven't shown too much interest. So, I do make an adapter set to put the TFS tunnel ram 2 X 4 intake manifold on the ProFiler # 205 heads. You need to realize that the ProFiler ports are raised +.200" over the Ford C-460 heads. Therefore this adapter plate has to be thicker, than the C-460 adapter plates like what Nevs has. I presently have two sets of them in stock, (along with taller china wall spacers) and ready to ship. Note, that because they are thicker, they are heavier.

Hope this helps,

Charlie Evans

Nick, the single four pentroof top is actually taller than 2x4 like I have, so you would have to have a scoop at least as big as mine.

sorry to bring an old thread back up but how does the tfs tunnel ram with singal carb do as far as cylinder distribution, are the egts close cylinder to cylinder or does it starve the outer four?

We did the dyno testing for TFS using the pent roof top on George and Carl Keown's 572 TFS A-460 headed engine. That was several years ago, but I do remember that the EGT's were very consistent for all 8 cylinders and showed absolutely no fuel distribution problems. I gave copies of the dyno pulls with both the 2 X 4 top and the pent roof top to Ron and Mark at TFS.

Hope this helps,
Charlie Evans

no one has answered the original question yet. how much taller than a cast manifold is a tunnel ram manifold? I am curious now too lol

The adapters and the TFS cast tunnel ram for the "A" heads fit the "C" heads very well after a bit of port matching.