single plane intake elbow
Le Mans Master
Joined: Feb 2005
Posts: 6,479
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From: Clearwater Florida
........ Its an EFI'ed Old School Offenhauser Cross Ram from the late 60's ... a great friend of mine , and an awesome welder put it together for me ..... It saw some time on the new motor on the engine dyno but due to complications that went beyond the paid for dyno time I never got a full pull with it ... but what I got was impressive ... can't wait to get it back on the motor after the bugs are ironed out of the tune ............
Pro
Joined: Feb 2005
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I'm running a superram and debating about doing a single plane....I have lots more room under the hood then a corvette/camaro so that's not a problem. Think there is a way to build an elbow that would make more low end TQ like the superram even if it hurts top end power some? I just want an intake thats easy to work on vs the superram and has the TQ of a SR. I have read on a thread on ls1tech.com about single planes and a guy commented that the elbow effects TQ. If there was more pleum space would it create better TQ or would a longer smaller tube type elbow create it? I feel like the ford performance type elbow with a 2-4" carb spacer would help produce more TQ but may hurt upper rpm power....what are your guys thoughts?
Last edited by 355tpipickup; Mar 20, 2015 at 12:49 AM.
Safety Car
Joined: Sep 2001
Posts: 4,155
Likes: 553
From: Glenbeulah Wi
I'm running a superram and debating about doing a single plane....I have lots more room under the hood then a corvette/camaro so that's not a problem. Think there is a way to build an elbow that would make more low end TQ like the superram even if it hurts top end power some? I just want an intake thats easy to work on vs the superram and has the TQ of a SR. I have read on a thread on ls1tech.com about single planes and a guy commented that the elbow effects TQ. If there was more pleum space would it create better TQ or would a longer smaller tube type elbow create it? I feel like the ford performance type elbow with a 2-4" carb spacer would help produce more TQ but may hurt upper rpm power....what are your guys thoughts?
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
OMG, my idea is already incarnated into reality. C409 i think u almost gave a corinary problem. Tell me about that TPI plenum. How well does it work? Performance? Is another one alvailible or can i have one made for me? Just the converted phenum as it should bolt up to anysquare bore intake. Man u really got me hooked now. Can u help me out with some info C409?
BTW that looks like real craftsman work as it looks all squared up correctly too.
Le Mans Master
Joined: Feb 2005
Posts: 6,479
Likes: 565
From: Clearwater Florida
OMG, my idea is already incarnated into reality. C409 i think u almost gave a corinary problem. Tell me about that TPI plenum. How well does it work? Performance? Is another one alvailible or can i have one made for me? Just the converted phenum as it should bolt up to anysquare bore intake. Man u really got me hooked now. Can u help me out with some info C409?
BTW that looks like real craftsman work as it looks all squared up correctly too.
BTW that looks like real craftsman work as it looks all squared up correctly too.
Last edited by C409; Mar 21, 2015 at 08:57 AM.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Please stay in touch then and let me know what u can find. I plan to use it on my LT1 camaro and i think the throttle bodies are the same but i just want the plenum converted as i will choose a different intake for my LT1 and as long as it bolts to a square bore carb mount it shouldnt be a problem. The LT1 has the vacuum fitting on the drivers side though and a threaded boss for that on that side would be nice though im sure there are vac fittings in rear as per stock TPI. Something else would be nice is an EGR mount/boss as the LT1 intake has it on the rear of the intake. I just need a location to carry the vlv for smog inspection - dont need a functional EGR.
When i first looked at the TPI plenum i saw the bottom was irregular and realized conversion would be a machine shop operation. And i hate trying to explain a modification to anyone as something always get lost in the communications.
BTW im just using it on top of 350 c.i. and maybe 355. I doubt ill ever go even to 383 so that plenum should be a great fit for sizing. Im having traction problems and too much wheel spin now.
Thx for replying C409.
When i first looked at the TPI plenum i saw the bottom was irregular and realized conversion would be a machine shop operation. And i hate trying to explain a modification to anyone as something always get lost in the communications.
BTW im just using it on top of 350 c.i. and maybe 355. I doubt ill ever go even to 383 so that plenum should be a great fit for sizing. Im having traction problems and too much wheel spin now.
Thx for replying C409.
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Team Owner
Joined: Dec 2007
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....... Pologreen1 has one of my modified plenums ... I'm not sure if he intends to use it or not ... it worked successfully on the 409 and 406 engines that were previously in my car ... the engine pictured with the LS coils is a 421 and I have yet to verify by pure scientific methods that it performs as well on bigger cubes , but I am confident that it will ... I could have more of these made but it has been a while and I would have to see what today's cost would be ... It requires a billet aluminum carb spacer (they are pricy) , then the bottom of the plenum has to be milled flat and the rest is welding the spacer on and welding the portholes closed and opening the bottom of the plenum ... there would also be an extra charge for porting the mouth of the plenum to match larger throttle bodies ..... the real beauty of it is that all the original hook-ups are maintained , reducing the amount of fabrication time needed for vacuum , linkage , and air filtration ... and on the right Single Plane intake manifold , the thermostat housing is NOT an issue on L98 or Gen 1 small blocks ......
In the future I may plan to sell it, but I am really intrigued with the idea of using it. I was going to get a sheet metal one made but this one should work better than an elbow. I might try to compare at some point.
BTW I wish I knew how the smokey intake did and if it would feed my motor.
Last edited by pologreen1; Mar 21, 2015 at 06:55 PM.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Polo i think your talking 'bout the TPI conversion plenum. What i liked 'bout that TPI plenum is it has extra volume past the turn into the carb spacer/intake. This really helps turn the air and reduces pressure losses/restriction on air flow. That and it kinda disguises the single plane intake - i dont think any smog technician would notice the difference. Though in Nevada i think modified intakes will make it as long as the filter box is there with a throttle body on the front of plenum. But the TPI plenum looks much more stock like than say a Nitrious Outlet air horn.
I think anything is better than the stock LT1 intake as the runners are just to short for any pulse tuning to happen less than 15,000rpm. And those short runners allow alot more reversion into adjacent cylinders at low rpm - mainly cyls 5 & 7. I expect there is power and economy to be had just by switching to longer runners. LT1 intake was a over reaction to the long runners on the TPI that killed higher RPM power. Since my camaro hood and windshield cowl clearance is so limited i have to look elsewhere for intakes. Hard to bet the old school sbc designs that were developed and proven for nearly 50 years.
Ok thats my 2 cents.
I think anything is better than the stock LT1 intake as the runners are just to short for any pulse tuning to happen less than 15,000rpm. And those short runners allow alot more reversion into adjacent cylinders at low rpm - mainly cyls 5 & 7. I expect there is power and economy to be had just by switching to longer runners. LT1 intake was a over reaction to the long runners on the TPI that killed higher RPM power. Since my camaro hood and windshield cowl clearance is so limited i have to look elsewhere for intakes. Hard to bet the old school sbc designs that were developed and proven for nearly 50 years.
Ok thats my 2 cents.