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no tunnel rams for vortec heads?

Discussion in 'The Garage' started by ryan22re, Jan 18, 2006.

  1. ryan22re

    ryan22re 1/2 ton status

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    how come? with the popularity of these heads, seems to me somebody would be making a tunnel ram. ive looked and searched, even the off brands. anybody have a source for them?

    what about a couple of pictures or write up of what it would take to modify a regular intake to fit? i know about the bolt hole stuff, just wondering about the port locations. seems to me that vortec heads have a higher port location that standard sbc heads.
     
  2. Leper

    Leper 1/2 ton status

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    IMO the Vortec motors do not offer the power potential of other motors enough to warrant production of a tunnel ram setup.
     
  3. ryan22re

    ryan22re 1/2 ton status

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    are you sure? the vortec heads are the best flowing production heads out there. it wouldnt be unusual for someone to put a tunnel ram setup on a set of old "double hump" heads would it? and vortec heads have more power potential then the old heads could ever dream of.

    *edit*

    why then does edelbork offer a single plane intake that advertises power in the 3500-7000 rpm range? seems to me the power potential is there.
     
  4. marv_springer

    marv_springer 1/2 ton status

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    Ryan,

    I would agree w/ Leper.

    I agree w/ this too....!

    I don't think you need 2-4's to feed a small block to 7k rpm. Prolly have better performance/durability w/ a single. I think the real use for a tunnel ram would be >>> 7k.

    Marv
     
  5. ryan22re

    ryan22re 1/2 ton status

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    you are right. i dont need 2-4's. what i do need is an intake with long runners to build a custom efi intake. that is my plan. street based tunnel rams seem to fit the bill.
     
  6. marv_springer

    marv_springer 1/2 ton status

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    Ahhh..... I see your purpose now...

    How bout a modified TPI intake...? But I guess you're facing the same issues there, huh....

    Marv
     
  7. ryan22re

    ryan22re 1/2 ton status

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    yeah but the base and runners would damn near cost a grand. i see tunnel rams on ebay for $100 or so. plus some labor to mod it to fit vortec heads and it still comes out smelling like a rose.
     
  8. Brians89K5

    Brians89K5 1/2 ton status

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    If you want a tunnel ram, or are looking for the long runners go with a TPI setup from an old camaro. the tunnel rams are made for building lots of HP high up in the RPM range. You'll end up with a soggy bottom end with little to no throttle control untill your really winging the engine. What it is you are tying to achieve? Looking for long runners tells me you are trying to get bottom end torque, but a tunnel ram isn't geard for low RPM use. Also, the vortech heads as well as they do flow, flow the best around 3500 to 4500 rpm, so maybe there are no tunnel rams out there because a tunnel ram would over feed the poor things? A 160 cc intake port can only handle so much air. Also, with a set of vortech heads, the TBI intake from edlebrock and a 383 underneath it with a small cam, you can buld 435 lb foot of torque at 3500 rpm. Close up the lobe senters even more and you even get as close as 3000rpm peak torque!!! talking about a Towing/wheelin engine!


    ~Brian
     
  9. sled_dog

    sled_dog 1 ton status

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    the high RPM characteristics of Tunnel ram comes from the straighter intake shot from the carb to the valves. Longer runners are better for torque, there is just no way to fill up those big runners that aren't designed for low end fuel atomization at Low RPMs. When it is a dry system(multi port EFI) the longer runners help torque. Would a tunnel ram be the best option for that? eh... I do not think so.

    Here is the intake I would consider if I were you. Won't be great torque wise but its intended for just this purpose(MPFI on a Vortec head small block)
    http://www.holley.com/products.asp?product=9901-107

    http://store.summitracing.com/defau...eywordSearch&DDS=1&N=115&target=egnsearch.asp
     
  10. ryan22re

    ryan22re 1/2 ton status

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    tpi manifolds are out. no power over 4500. vortec bases for tpi intakes are $400. not to mention the "high flow" runners are $300. then another $250 for a throttle body. no thanks.

    tbi is out too. granted, it will stay in my truck until i swap it out, i just dont like it in a performance engine.

    the ls1 engines have long runners too. something like 20 inches long. tpi runners were like 23 inches. the difference is the runner volume. tpi had none. the ls1's have a very wide rpm range. same thing i am looking for. long runners with enough volume support good power. so you can have the best of both worlds. low rpm grunt and high rpm power. thats what i am looking for.
     
  11. sled_dog

    sled_dog 1 ton status

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    let me know when you find it because that is exactly what I want. I got an LT1 intake to get around the TPI RPM issue, but the low end torque characteristics didn't seem to be to my liking and it was going to be too much $$ I dont have so I sold it for quick cash.
     
  12. ryan22re

    ryan22re 1/2 ton status

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    somebody has to have tunnel ram laying around that they could measure the port length and volume so we could make a comparison. ive got numbers on these intakes from a magazine:

    stock tpi 23.375 inches
    accel super ram 21.125
    stock lt1 9.00
    stock ls1 20.00
    edelbrock perf rpm
    carb style 12.125
    edelbrock victor jr
    single plane 11.625

    that is total length from the plenum to the intake valve seat.

    just some fuel for the fire.
     
  13. sled_dog

    sled_dog 1 ton status

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    think about ricers with individual throttle bodies or old flat heads with carb per cylinder. They don't/didn't have big long intake manifolds. And they make more upper RPM power. Shorter runners are for high RPMs, Tunnel Rams just make a very nice DIRECT line from the throttle blades to the valve and have to be tall to do so.
     
  14. ryan22re

    ryan22re 1/2 ton status

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    yeah, but the "directness" is what you are after. air doesnt like to go around corners. velocity is where it is at. comparing a single plane to a tunnel ram, id bet the runner cross section is close, the tunnel ram has longer runners, so given the same cross section, id bet that the tunnel ram could make more torque due to the increase in port volume and velocity.
     
  15. Brians89K5

    Brians89K5 1/2 ton status

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    The Ls1 engines don't come alive until about 4grand. The lt1's had better low end torque than the ls1's did, just didn't rev out as much. Directness is a good idea, but you know the best flowing and performing intake for carbs right now is the edlebrock airgap. The way the bend in the runners is, directs the air/fuel towards the outside of the runner yielding in higher air/fuel atomization yileding in a better bang for your buck. All the big boys making all of the big power are doing it with single carbs and or tpi. One of the big things is the mini ram, but then again your bumping the powerband way up in the RPM range. I suppose its all in what you want. If you intend on drag racing your engine build it to pull 7k RPM. If your gonna tow and wheel with it then build it to pull 3500 to 4500. My old 95 trans am would out pull a ls1 car and smoke it in the 60 foot times and in the quarter mile and I short shifted the 4l60e at 4500 rpms but my intent was not really to drag as much as I wanted a pleasurable vehicle to drive. Shift recovery points are also critical to making a hunk of metal run quick. The tunel ram on my big block from bottom of the butterfly's to the front of the intake port is about 23 inches. My big block with dual 450's is crisp and clean until I come down off of WOT, then I get a little of intake reverb and my engine wants to come out of its idle. meh, food for though I suppose. I am curious to see how it turns out if you decide to convert a tunel ram into fuel injection.

    ~Brian
     
  16. sled_dog

    sled_dog 1 ton status

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    you say all the big boys are going the TPI and dual plane route but there are a lot of LS1 cars making 500-600hp with factory intake manifolds.... I've never ridden in an LT1 powered vehicle but the LS1 and truck engines pull hard right through the powerband IMO.
     
  17. ryan22re

    ryan22re 1/2 ton status

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    so back to the question at hand.

    does anyone make a vortec tunnel ram or have any ideas what it would take to modify one to fit a vortec engine?

    or am i on my own?
     
  18. sled_dog

    sled_dog 1 ton status

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    Vortec heads can be redrilled to fit standard bolt pattern intakes. However the ports won't properly line up, so its a waste of time IMO.

    Why is i tyou are so set on Vortecs? Have a set or just figure its cheap easy HP? In many ways it is, but for me I'd spend the money that I would have put into Vortecs(crack checking, new valve springs, self aligning roller rockers, valve, and port work) and buy a new set of aftermarkets. Just saying...
     
  19. dyeager535

    dyeager535 1 ton status Premium Member

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    In his other post he mentions he got a set for $100, so that's the Vortec angle. :)

    Just helping out because he's probably asleep or something, might keep the discussion going!
     
  20. ryan22re

    ryan22re 1/2 ton status

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    give you a run down of what i will have in a set of vortecs vs. a new set of heads.

    my vortecs:

    $100 used.
    $57.05 for tool from comp cams to cut the guides and the spring boss down.
    $15.24 for the arbor to either chuck it in a 3/8 vise or the mill at work.
    $24.99 for the tool to slot the pushrod holes with a 5/16 drill bit.
    $150 springs and retainers. (high est)
    $40 screw in rocker studs. (have drill bits, tap and a mill already)

    $387.27 still leaves me plenty of extra cash to have them tanked, surfaced, and checked for cracks. i didnt include self aligning rocker arms, because you would have to buy those with the other set of vortecs, but the price difference between self aligners and regular is at best $25-30.

    vs. $525 for new vortec heads that still need to have screw in studs added and the valve guide/spring boss machined for lift over .475 (which is what i want).

    or. $950-1000 for aftermarket cast iron heads.

    or. $1200 a set for aftermarket alum heads.


    that is the reason i want to use vortec heads. :D
     

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