Re: old school tunnel ram and carbs question
 

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fuel bowels

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I think you mean bowls . 'Bowels' are a part of the human anatomy, just below the belt loops and out back.

Seriously though, that is a fascinating essay on tunnel ram set-up. Makes me want another one. No wonder my 327 ran like s__t 25 years ago when I borrowed a buddy's setup! Too much carb (600's).

Re: old school tunnel ram and carbs question
 

Yeah---Weren't those Very https://www.yenko.net/ubbthreads/imag...mlins/cool.gif times---

Re: old school tunnel ram and carbs question
 

I've come into this thread a little late, but wanted to add a few of my thoughts.

I've run several 1850 carbs with both tunnel and x-ram intakes. I've found that street driving required me to restrict the liquid line in the metering block. Since the 600 carb was factory tuned to provide idle- we'll say for 8 cyl. in this case, multiple carbs will then be very rich at idle- beyond the adjustment of the idle mixture screws. With this done, the 1850's can be tuned with conventional methods to run very well on the street. I'm willing to discuss this more if anyone is interested.

As for the vacuum secondaries, needing to be changed I’ll have to disagree. Although tunnel ram does lower the engine vacuum, the secondaries operate off of venturi vacuum. They are completely tunable on tunnel ram. I also think they help in making a tunnel ram engine more streetable because they only open X amount from the venture signal. Mechanical secondaries can give too much CFM too easily.

I actually like the look of sideways mounted carbs. When/If you remove the jet plate and add a secondary metering block to an 1850 carb (to allow standard jet changes) you can no longer mount the carbs inline. Sideways mounting also helps with fuel slosh.

Plugs do tend to foul with multiple carbs due to fuel puddling in the intake, but a vintage MSD 7A will remedy that. I’m sure any hot ignition system today would work as well- I just like the old MSD 7 before they went to the 7AL.

Re: old school tunnel ram and carbs question
 

when you say "restricting the liquid line " are you talking about lowering the fuel pressure down to control flooding by adding a pressure regulator ?? https://www.yenko.net/ubbthreads/imag...lins/dunno.gif.also the secondaries will work correctly without the vacum line connecting them together https://www.yenko.net/ubbthreads/imag...lins/dunno.gif

Re: old school tunnel ram and carbs question
 

The only other problem I don't like about running the carbs sideways is you have to cut an extra wide hole on the hood the clear the carbs and linkage. The extra large hole looks odd when the hood is closed (or open for that matter).
From your first thread it sounds like you want to make the car period correct. I would say only 5 out of every 100 street cars ran the carbs sideways. You can do what you want.

In terms of the vacuum secondaries There was a huge differnce when I ran the balance tube kit...for the better.

Re: old school tunnel ram and carbs question
 

Unfortunately, I was in the ER and just got released. I thought about this thread while I was in there and I'm glad to reply. The liquid line in the metering block is set up for 8 cylinders, so by having 2 1850s on there, there will be enough liquid to feed 16 cylinders. By restricting the metering blocks to only feed 4 cylinders each, you have 8 cylinders being fed and idle will not be super rich-very streetable.
The vacuum secondardies will work fine by themselves. They are adjustable by changing the springs in them.
If you have more questions, maybe I could post a picture of them.

Re: old school tunnel ram and carbs question
 

a question..when we buy these so called matched tunnel ram holleys with the kit like from Summit are they not metered correctly..I was getting a good handle on this until the last few posts...

Thnx Bud

Re: old school tunnel ram and carbs question
 

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The only other problem I don't like about running the carbs sideways is you have to cut an extra wide hole on the hood the clear the carbs and linkage.

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Leave the hood off and chrome the hood hinges and springs. Then drive around with the hood hinges in the "open" position. Anyone remember that? A noisy gear drive adds to the impact. Suddenly it's 1979.

Re: old school tunnel ram and carbs question
 

Bud
The "matched" carbs from Summit/Jegs do not have anything special done to them. What Summit or Jegs mean by matched is they are the same part number https://www.yenko.net/ubbthreads/imag...lins/smile.gif ..and I'm being serious.

Plowman, I did not have to change the springs in my vacuum secondaries but in my friends street rod we did experiment with various springs. You mention you can run the vacuum secondaries by themselves(meaning without the vacuum balance kit). I found my car ran much better with the vacuum balance kit-because both secondaries open and close at the same time. I have yet to talk with someone who's engine ran worse with them. Of course everybodies setup is different...and some people just get lucky. I've talked to some people who took 450 holleys out of the box and they ran perfectly with no tuning whatsoever. Some people I talked with changed just about 3/4 of the components on the carbs and they still would not run right.

You talk about blocking metering plates etc to decrease fuel flow richness. I did that by running small 390's. I don't think my small 289 with metered down 600's would have run as good as the 390's.

Re: old school tunnel ram and carbs question
 

has anyone ran a 6,000 rpm oval port big block with 450 holley's? it would seem to me that 900 cfm would still be plenty. i suppose the 1200 vacuum carbs would work as the carbs would deliver what the engine needed. i'm curious how my 454 oval port would respond as it has a 10" converter and 4.10 gears. i know i like the 450 carbs. mike

Re: old school tunnel ram and carbs question
 

There was a '66 Chevelle in Car Craft in late '80's that ran 450's and the guy said they ran good.

450's would be fine for street cruising in a 454.

Re: old school tunnel ram and carbs question
 

No argument with the balance tube Whitetop. They will certainly make the transition of the secondaries opening smoother. It should not influence the way they close since they close mechanically.

To clarify the liquid line mod, it is not changine the fuel pressure to the carbs, but restricting the fuel flow through the metering block circuits. If you remove your front fuel bowl and then take the metering block out and look on the back side that faces the carb body you will see the liquid line. It can eaily be identified by the only pair of small circuits (holes) which are side by side. One pair on the right and one on the left. It is towards the bottom of the block.

Restricting the liquid line is a tune I like to do on the popular 1850 600 cfm carbs. I did run a pair of 390's on a X-Rammed 327 with the 327/350hp cam. When we swapped them out for a pair of 600's I modified there was a noticable improvement in drivability on the street and ET at the strip. I'm not trying to say it would improve on every setup. I did have better result with 600's over stock 390's on the cars I tuned.

The old 4295 Holley's that were the compliment to the Z28 crossram were 585cfm each and is a lot closer to 600 than 450 is. I think 'ol Smokey U knew a little more about carbs than I do and I'll take his professional opinion that that is the best setup for a little 302.

Summit and Jeggs sell their popular multible carbs kits with smaller carbs than that- so it certainly can work either way. Some like to use smaller carbs, I like to use bigger ones.

I would encourage Musclcar to try and mod the 1850's he has and see what he thinks.

Re: old school tunnel ram and carbs question
 

hey Plowman can you show me a pic of how you like to restrict the fuel on the block...it makes perfect sense this is why we have such a hard time with these at idle on the street...whitetop I kinda figured you were going to say that about the matched carbs..."and this complete set-up comes with our special matched tunnel-ram holleys".. https://www.yenko.net/ubbthreads/imag...ins/tongue.gif remind me to take summit off the christmas card list for next year...

Bud.

Re: old school tunnel ram and carbs question
 

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The only other problem I don't like about running the carbs sideways is you have to cut an extra wide hole on the hood the clear the carbs and linkage.

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Leave the hood off and chrome the hood hinges and springs. Then drive around with the hood hinges in the "open" position. Anyone remember that? A noisy gear drive adds to the impact. Suddenly it's 1979.

[/ QUOTE ]

https://www.yenko.net/attachments/130467-pimpvert.jpg

Re: old school tunnel ram and carbs question
 

I'm going to try to get a picture up to show the restriction. I enjoyed the picture you posted.

Re: old school tunnel ram and carbs question
 

This is a good thread--Good info all around---I dug thru some of my stuff to dig out a Motion Member--The Ridge Runner----I'm just showing the other side of the coin--- https://www.yenko.net/attachments/130538-ridgerunner.jpg The Ridge Runner Ram

Re: old school tunnel ram and carbs question
 

-- https://www.yenko.net/attachments/130539-ridgeengine.jpg

Re: old school tunnel ram and carbs question
 

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https://www.yenko.net/attachments/130467-pimpvert.jpg

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Uhhh, close but no cigar...

Re: old school tunnel ram and carbs question
 

80's enough for ya..???

https://www.yenko.net/attachments/130751-78camaro.jpg

Re: old school tunnel ram and carbs question
 

Here is a pic of a metering block. I tried to show the liquid line restricted. You can see a non restricted line on the other side of the block. The pencil is pointing to the restricted line. I used a an 0.018" steel wire and bend it in a "U" shape so that it fits in both ports. It is retained by the metering block flat gasket.

I get the wire from just about any parts tag, they all seem to use this wire and are readily available in most shops. If you can change a powervalve, you can do this mod.

https://www.yenko.net/attachments/130911-600m2.jpg

This shows the wire installed in the two holes the pencil is pointing to as well as another similar wire not installed.

Re: old school tunnel ram and carbs question
 

[ QUOTE ]
Here is a pic of a metering block. I tried to show the liquid line restricted. You can see a non restricted line on the other side of the block. The pencil is pointing to the restricted line. I used a an 0.018" steel wire and bend it in a "U" shape so that it fits in both ports. It is retained by the metering block flat gasket.

I get the wire from just about any parts tag, they all seem to use this wire and are readily available in most shops. If you can change a powervalve, you can do this mod.

https://www.yenko.net/attachments/130911-600m2.jpg

This shows the wire installed in the two holes the pencil is pointing to as well as another similar wire not installed.

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Hey thnx..great idea I like it!! easy to change sizes to..we have some stainless I am going to measure it.

Re: old school tunnel ram and carbs question
 

the best carbs are 660 center squirters all others feed most of the accelerator shot down 2 cylinders and starve the other 2 hence the bogging problems inherent with these setups the 660s sqirt a 4way shot down the center of the carb and tend to charge the cylinders evenly. They cost a mint now ebat runs 500-600 apair used i dont think holley makes them anymore. They were designed for dual 4 applications. usually only double pumpers are mounted sideways since they dont fit ny other way vac sec carbs are usually mounted inline.

Re: old school tunnel ram and carbs question
 

okay finally i'm going to put the tunnel ram on this weekend !!.one question though ?? is what is a good baseline carb set-up [i.e] jets,power valves and pump cams for these 600 vac secondary carbs.right now on my motor i'm running a very nicely tuned holley 750 DP,it has these parts in it https://www.yenko.net/ubbthreads/imag...ins/tongue.gifrimary - #76 jets, #8.5 power valve, #31 squirter and orange pump camsecondary - #80 jets ,#35 squirter and red pump camso what size jets will work i know the power valve will stay at 8.5 and the pump cams orange "maybe" https://www.yenko.net/ubbthreads/imag...ns/worship.gif https://www.yenko.net/ubbthreads/imag...ins/3gears.gif

Re: old school tunnel ram and carbs question
 

How did you make out this weekend working on the tunnel ram? Jets stay the same size. Remove choke and choke plates on each carburetor (if it backfires they will flip 180 degrees).

Re: old school tunnel ram and carbs question
 

well i went to a #64 jet,#31 squirters,white pump cams,a #9 secondary plate and it seems to work good.there is no choke plate in either carb since i live in sunny so. california.i might try a 50cc reo pump though and see what it'll do because of the large plenum and long runners to the intake valves.also my dual carb linkage is set up right now for both to open at the same time instead of progressive.again this combo seems to be working quite well and feels really responsive when i hit the loud pedal.my friend did a really nice job in restoring the intake and zinc chromating the carbs https://www.yenko.net/ubbthreads/imag...ins/3gears.gif

Re: old school tunnel ram and carbs question
 

hey guys,I have custom set of center squiters that are too big for my motor.They have dominator bowls and F&R metering blocks if anyone can use them.ONLY a couple pulls on the dyno.Email if interested before I put them on ebay.Tom

Re: old school tunnel ram and carbs question
 

here is a pic of the engine with the edelbrock TR1-X tunnel ram and holley 600 vac secondary carbs http://upload.79camaro.com/cpg/displ...amp;fullsize=1

Re: old school tunnel ram and carbs question
 

Hey everyone, wanted to start with saying this has been a really helpful string. Im a younger guy, bought a chevelle when i was 17 and now just deciding its time to dump some cash into it. Kicking around my friends garage is a rectangle port tunnel ram, i like the look of tunnel rams, but i have oval port heads. i read somewhere recently that you can use the rectangle port intake with matching gaskets on oval port heads.. any ideas or comments here guys?

Re: old school tunnel ram and carbs question
 

You can run square port intakes on oval port heads, I've seen it done with success, but it is certainly not the "optimal" situation. Square port intakes are designed for square port heads, and are typically higher rise and often times of open plenum (single plane) design. These high rise and/or single plane intakes are a poor match not only in port type but overall design for the smaller, less flowing oval port heads. I'd say you can get away with it if it's a dual plane fairly low-rise square port intake going on oval port heads, but if it's a high rise single plane or something really high rise like a tunnel ram I'd say forget it. It'll give you more headaches and rob you of more power than the "cool looks" will ever reward you with. Just my opinion, I'm sure others will chime in.

Re: old school tunnel ram and carbs question
 

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DirtyS</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Here's a photo of an edelbrock tr/(2) 600cfm carbs-str. linkage----From that Motion car---maybe this will help--Just some info &lt;img src=&quot;https://www.yenko.net/ubbthreads/imag...eers.gif&quot; alt=&quot;&quot; /&gt; https://www.yenko.net/attachments/128...oooooooooo.jpg </div></div>

If that is a Motion car it really makes me question some of the mystique and values floated around for them.

Looks like something the typical backyard guy would do with some rubber fuel line.

Not impressed. </div></div>

Those look like the 750 mechanical secondary tunnel ram carbs that they don't make anymore, see the fuel line leading up to the passenger side.

Re: old school tunnel ram and carbs question
 

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bob Hollinshead</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DirtyS</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Here's a photo of an edelbrock tr/(2) 600cfm carbs-str. linkage----From that Motion car---maybe this will help--Just some info &lt;img src=&quot;https://www.yenko.net/ubbthreads/imag...eers.gif&quot; alt=&quot;&quot; /&gt; https://www.yenko.net/attachments/128...oooooooooo.jpg </div></div>

If that is a Motion car it really makes me question some of the mystique and values floated around for them.

Looks like something the typical backyard guy would do with some rubber fuel line.

Not impressed. </div></div>

Those look like the 750 mechanical secondary tunnel ram carbs that they don't make anymore, see the fuel line leading up to the passenger side. </div></div>

Another clue-see there is no fuel transfer tube from primary to secondary, also the mechanical secondary linkage. I don't think this was as simple of a setup as originally thought earlier in this thread. Those aren't vacume secondary 600 carbs on there and I would be they are the 750 tunnel rams carbs that you can no longer buy. I bet that engine hauled ass!