Intake design for stock appearing class and needed a winter project

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furrystump

furrystump

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So I’m tired of paint and body work and it’s to cold to spray color now anyways. So I have embarked on tackling the intake on my car. I’m currently running a stock 68-69 340 intake with the divider cut down and the ports being blended and gasket matched. The car runs a stock appearing stock tire class. This requires the use of the stock casting intake. Everything from the paint down is free game. For me, there can be NO external changes. No casting one out of aluminum etc. I’m going for as close to a single plane intake with a more direct intake runner as I can do. Keeping in mind it ALL has to be hidden under the stock intake. I have removed the lower intake runner system which created a flat bottom with which to work with. Then I have remove the cast four hole section in the plenum.
 
I made the new plenum which bolts to and will be epoxied to the bottom to seal it to the underside of the original intake. I will totally seal the old upper intake tract with epoxy and will not be used.

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The holes will be removed. This is the plenum the runners will be straight off the plenum.

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It should give me 6” from carb base to plenum floor. I have made the runners which taper from 1 1/2”x 2 1/2” down to felpro gasket size.

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I will inset flanges into the stock sealing surface and use the original intake bolts/boss to sandwich the plates to seal it.

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Cool effort! Lots of work for sure.

It kinda sounds like cheating to me but I'm unfamiliar with stock-appearing classes. For all I know it's encouraged.

Keep us posted! I want to see how it turns out.
 
Any internal modification is allowed. Well no raised cam’s or decks. No nitrous. When done I will post pictures of a stock intake and this one and see who can pick the new one. I have probably just made a very heavy paper weight, but who knows. I would be happy with 1/10 and a couple of mph’s
 
This to me is absolutely bizzare. But keep at it!!!!! LOLOL
 
Current intake and plenum I’m running and can always go back.

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CudaChick1968 said:
Cool effort! Lots of work for sure.

It kinda sounds like cheating to me but I'm unfamiliar with stock-appearing classes. For all I know it's encouraged.

Keep us posted! I want to see how it turns out.
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Not cheating at all. It just has to be stock appearing, no different than porting the heads.

Keep us updated on how it works. Out of the box thinking for sure.
 
I remember reading where Petty cut out the entire 59 degree lifter valley out of the blocks and rewelded them to 48 degree.

I've seen Brezinski's intakes cut and rewelded , too.
 
Track to begin with, I have AFR gauge to get it close and keep an eye on it for going lean. The good thing is it will SMOKE if it has a vacuum leak. It will pull in crankcase air if anything. I’m confident I can make it not leak vacuum. I plan to coat all the seams with splashzone on the exterior. Also make a sheetmetal cover to keep hot oil off it and catch any pieces that might come off and could cause damage to the cam or lifters. Also plan to pin with a screw the big blocks sealing the original upper tracts. I’m losing about 3-4”’s of runner length, but I really can’t help it. I can’t use the side of the vertical plenum like a traditional single plane does. No room without changing the outer manifold shape around the choke well and heat cross over well. If it picks up anything significant and If it runs with steady AFR, doesn’t lose mph and It doesn’t show distribution issues on the plugs, it would probably find its way on a chassis dyno before I change anything else.
 
Well, knowing the history of this cars visit in the winner's circle, one more tenth and a couple of mph will keep it there. Good luck.
 
I really would like to see an increase in mph. If it shows promise, but I lose to much in the 60’ I can pull the 4:10’s out and borrow more gear. If it likes that then I know I’m onto something. The plan is a 904 in the future which will require new converter. I would definitely run it on a chassis dyno before that change.
 
I was lucky that day, but I’m a couple of tenths behind a pesky small block 67 chevy II. Any improvement and I can start to taylor the rest to the increase intake flow. Sooner or later a roller is in the cards. Also I can get 130 lbs out of the car with a couple of changes and going to 904. That should sharpen up my poking stick pretty well! Poke Poke Poke!
 
Nice work, have a buddy that races FAST with a 383 based Road Runner (now 499 cid) he curses his 308 intake everday!
 
furrystump said:
I was lucky that day, but I’m a couple of tenths behind a pesky small block 67 chevy II. Any improvement and I can start to taylor the rest to the increase intake flow. Sooner or later a roller is in the cards. Also I can get 130 lbs out of the car with a couple of changes and going to 904. That should sharpen up my poking stick pretty well! Poke Poke Poke!
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What class would you be in with a 4 speed?
 
Krooser said:
I remember reading where Petty cut out the entire 59 degree lifter valley out of the blocks and rewelded them to 48 degree.

I've seen Brezinski's intakes cut and rewelded , too.
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I looked at Brezinki’s, but on a mopar intake they only go to level two of three and it is a bunch of money. You end up essentially with the the best flowing “divider cut down and ported” intake. I’m not saying that in a negative way, but there might be more using as clean a sheet of paper as I can. There is still some I can do to the current one. Open up the entry more, round the the roof transition more etc. There’s more meat I can take out in beneficial areas.
 
Same class if it was a 4 speed.

I know the 383 RR, black? This is us at MIR.He’s car 99. Then he goes and tests and runs 11.5 or 6!!!!!!

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furrystump said:
I was lucky that day, but I’m a couple of tenths behind a pesky small block 67 chevy II. Any improvement and I can start to taylor the rest to the increase intake flow. Sooner or later a roller is in the cards. Also I can get 130 lbs out of the car with a couple of changes and going to 904. That should sharpen up my poking stick pretty well! Poke Poke Poke!
Click to expand...



I believe a 904 swap would put you right with that Nova. Good luck with the intake.
 
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