Setting up my intake and carb

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MushCreek
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Setting up my intake and carb

Post #1 by MushCreek » Sun Jul 01, 2018 6:21 am

I'm very slowly getting my 300 put together. Now with most of the pieces purchased, I'm ready to set-up the intake. What I have is an Offy 'C' type intake and an Autolite 2100 with a 1.08 venturi. The rest of the engine will be mostly stock other than EFI exhaust manifolds. I'm still undecided about a cam and/or rockers.

I have a Mr. Gasket 1933 which will adapt the 2100 to the manifold. I also have a stock carb riser with hook-ups for heater hoses. Do I want to use that or not? Or do I want to make a water manifold to bolt on to the bottom of the manifold? Priority One is driveability and reliability. I'm in SC, so temperatures can range from single digits to triple digits. I don't want a set-up that ices up on a cold morning dump run.

As I said, I'm still undecided on a cam set-up. I have a stock cam and rockers right now. The block is fresh rebuild with a rebuilt 240 head. Tranny is a C6 auto. Options would be a different cam, different rocker ratio, and/or an advance key for the cam gear. The engine is going in a '72 F250 which will be used for local hauling, and it can get hilly, so I need some grunt to get a heavy trailer up the hills.

pmuller9
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Re: Setting up my intake and carb

Post #2 by pmuller9 » Sun Jul 01, 2018 7:56 am

What is the compression ratio?

Backwoodswalker375
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Re: Setting up my intake and carb

Post #3 by Backwoodswalker375 » Sun Jul 01, 2018 8:13 am

I would recommend the hot water plate under intake. If you want to go "cheap" moneywise. I would run stock cam . Degree it in as close to straight up as poddible. Mr. Gasket makes off set keys. Use 6 cylinder chevy rockers. I would use a Dura spark 2 ignition. Set up advance as motor likes. Use the best cap rotor and wires you can get. Tune her good and you will have a motor that runs smooth as glass and pulls great. Bet you never have to open hood between oil changes. My reccomendation. Others will vary, of course.

SteveP
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Re: Setting up my intake and carb

Post #4 by SteveP » Sun Jul 01, 2018 9:13 pm

I put a heat plate on the bottom of my C manifold. I works great in cold weather but as the seasons changed and warmed up (central Mississippi, 90+ degrees) the manifold would get scorching hot and I was having a dieseling problem when I shut the motor off. Also I could hear fuel boiling in the carb when I opened the hood right after shut down. I have a 1/2" thick phenolic spacer between the carb and adapter. I'm going to add a 1/2" phenolic spacer between the manifold and adapter to try to cool the carb more.
I installed a bypass with with a ball valve to isolate the heat plate and this corrected the problem. In cold weather I'll just open the valve to get manifold heat when I need it.
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Harte3
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Re: Setting up my intake and carb

Post #5 by Harte3 » Sun Jul 01, 2018 9:28 pm

Looks like you are running headers? If so, that is where the heat is coming from. The water heat to the manifold would not be the problem as it runs the same thermostat controlled temp as the coolant in the engine and if anything should help.
'83 F150 300, 0.030 over, Offy DP, Holley 4160/1848-1 465 cfm, Comp Cam 260H. P/P head, EFI exhaust manifolds, Walker Y Pipe, Super Cat, Turbo muffler, Recurved DSII, Mallory HyFire 6a, ACCEL Super Stock Coil, Taylor 8mm Wires, EFI plugs.

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THE FRENCHTOWN FLYER
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Re: Setting up my intake and carb

Post #6 by THE FRENCHTOWN FLYER » Mon Jul 02, 2018 6:49 am

My experience with aluminum intakes is that you do not need water under the intake. To totally eliminate carb icing you will need to run warm AIR ducted from your exhaust manifold (header?) to the carb inlet, similar to a stock air cleaner.
FORD 300 INLINE SIX - THE BEST KEPT SECRET IN DRAG RACING

SteveP
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Re: Setting up my intake and carb

Post #7 by SteveP » Tue Jul 03, 2018 11:31 pm

Reply to #5 Harte3,

I have an opening in the radiator support that allows fresh air to flow past the header and take the heat out of the engine compartment below the truck. I also have an opening on the driver's side. There is a lot of fresh air flowing through my engine compartment. The header is also coated internally with Eastwood Internal Exhaust Coating.
With water flowing through the heat plate the intake gets so hot I can't touch it. Without water flow the intake still gets hot but I can hold my hand on it.
With water flow through the heat plate I get dieseling and boiling fuel. Without it I don't. The heat isn't coming from the header.

MushCreek
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Re: Setting up my intake and carb

Post #8 by MushCreek » Wed Jul 04, 2018 1:14 pm

How do I collect hot air off of an EFI exhaust manifold? I could cobble together some kind of plenum I guess. I'd like to run a stock, older air filter anyhow, so it would have a place to connect the snorkel hose. It would certainly provide heated air faster than heater hoses would.

I'm also undecided on ignition. I'm considering a DUI, but obviously a DuraSpark II could be pieced together for a lot less money.

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THE FRENCHTOWN FLYER
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Re: Setting up my intake and carb

Post #9 by THE FRENCHTOWN FLYER » Wed Jul 04, 2018 4:09 pm

I would make a sheet metal "stove" and mount it spanning two primary pipes. The Ford OEM system is actually pretty sophisticated having a thermostatically controlled temperature regulating flapper door and some even have a coolant temp controlled turn off feature.
FORD 300 INLINE SIX - THE BEST KEPT SECRET IN DRAG RACING

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woodbutcher
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Re: Setting up my intake and carb

Post #10 by woodbutcher » Wed Jul 04, 2018 4:15 pm

:hmmm: Also,it should`nt be too hard to rig up a carb heat setup like on an aircraft.Have seen a couple done that way in the past.Worked very well.
Good luck.Have fun.Be safe.
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