Vortec Advice
 

So, I'm finally getting around to cleaning up the Vortec engine I talked about in an earlier post:

http://67-72chevytrucks.com/vboard/s...d.php?t=712797

As I'm cleaning it up, I notice oil had been leaking from the fuel pump block-off plate. So I pull off the plate, and sure enough, the fuel pump passage is drilled through. I started thinking that maybe I'd be able to run a mechanical fuel pump (it's going to be carbed) rather than electric with pressure regulator and relays, etc. Unfortunately, the cam doesn't appear to have a fuel pump lobe (I put a rod in the passage and turned the crank by hand). So here's my conundrum: Do I put a cam that has a fuel pump lobe in it, something like the Ramjet 350, and simplify the fuel delivery, or just keep it as is and run the electric pump (I already have the pump, regulator, and relays, but I can always sell them or use them on other projects)?

The engine is going into a 72 Blazer 4WD and will be equipped with a Quadrajet, factory HEI with mellonized gear, and 2½ inch ram's horn manifolds. It will be a daily driver and I don't intend to race it, but I do enjoy quick acceleration (my other car is a 95 Z28 convertible). I would sacrifice a little performance for better fuel economy.

Re: Vortec Advice
 

I don't believe the ram jet has a cam lobe for a fuel pump as it is based on the vortec truck long block..
But you could get a aftermarket cam with a lobe for it..
I never looked at the ram jet cam I installed in my vortec crate to see if it had the fuel pump lobe.. but with the engine being based off the vortec truck crate and it coming with multiport efi.. there would be no point..

Re: Vortec Advice
 

The reason I believe it has a fuel pump lobe is the first review on the Summit page:

https://www.summitracing.com/parts/n...Reviews=Newest

I plan to call them and verify before buying, though.

Edit: I just spoke with a rep at Pace Performance and he verified that it does.

Re: Vortec Advice
 

Ramjet is not a vortec shortblock is has the HT383 cam.
Yes some vortec blocks were drilled but as you found out no lobe to operate the pump still. Mechanical pump is much less hassle, but installing a cam is lots of hassle. Just depends on what you want. If your going carb I would install an aftermarket roller cam personally and run the mechanical pump.

Re: Vortec Advice
 

This is the cam I ordered:

https://www.summitracing.com/parts/n...7395/overview/

I read an earlier post by CaptainFab recommending this one, and when I looked at reviews the people who installed it says it makes way more torque down low than the stock cam, which is what I want.

Re: Vortec Advice
 

I think you'll like that cam. And yes it does have a fuel pump lobe. They say you should run a bronze or roller tipped fuel pump pushrod, although we did not. The engine we built still does not have a lot of run time yet, so it is hard to say if the stock pushrod will eat up the fuel pump lobe.

Re: Vortec Advice
 

Thanks!

Re: Vortec Advice
 

Welp, g.m. performance list it as a vortec long block, with a cam and 1.6 rockers and the marine based efi..
I'm only going by what g.m. listing

Re: Vortec Advice
 

how does the roller tipped p/r not spin?
I'd think it spinning would be as bad as a roller lifter ..

Re: Vortec Advice
 

I don't see it listed as such anywhere http://www.chevrolet.com/performance...m-jet-350.html

Combine that with different pistons since it only has a 9:1 compression vs the vortec 9.4:1 and its certainly not a vortec shortblock. Kinda splitting hairs though, they are very similar.

Re: Vortec Advice
 

Description


You may recall the Ram Jet brand from the GM mechanical fuel injection systems of the 1950's. Back then everyone wanted a "fuelie" and today that's even more true. Chevrolet Performance Parts has brought back the Ram Jet name with its all new electronic port fuel injection systems for both small-block and big-block Chevy crate engines.

The small-block Ram Jet 350's intake manifold is styled like the Ram Jet of yesterday, but that is where the similarity ends. The all new Ram jet 350 uses state of the art components developed by GM to give you all of the benefits of modern electronic engine management. Who better to fuel inject your hot rod than the people who build 5 million fuel injected cars and trucks per year, including the one in your driveway. Unlike some aftermarket systems, Ram Jet offers great cold starts, hot starts, always ideal air to fuel ratios and exceptional throttle response, power and drivability.

The all new 350 horsepower Ram Jet 350 from CPP makes it easy to have electronic fuel injection on any vehicle originally equipped with a carburetor. The secret is the industry leading MEFI 4 controller. This new controller fits in the palm of your hand and was originally developed by GM Powertrain for marine applications. MEFI 4 is ideally suited for use in street rods, street machines and sportsman racers. Installation is simple; the Ram Jet 350 is an assembled 350 crate engine with Vortec heads, Ram Jet induction system, wiring harness, MEFI 4 controller, and detailed instructions.

Once installed in the vehicle, a user needs only to supply 12V power and fuel. Please note the fuel pump recommendations in the Ram Jet instruction manual.

The Ram Jet 350 has it all, great nostalgic styling, drivability unsurpassed by carburetors or aftermarket fuel injection, power to spare and a hot rod idle that sounds like Woodward Avenue in 1969 all over again! The 350 HO is not intended for marine use, and should only be used in 1973 and earlier pre-emissions street vehicles or any year off road vehicles. This engine offers great drivability, reliability, and a nice exhaust note.

Specifications:
Power: 350 HP @ 5200 RPM, 400 ft. lbs. of torque @ 3500 RPM
Displacement: 350 CID, 5.7L
Bore x Stroke: 4.00” x 3.48”
Compression Ratio: 9.4:1
Recommended Fuel: 92 Octane
Block: Cast Iron, 1 piece rear seal, 2-bolt main caps
Crankshaft: Nodular Iron
Connecting Rods: Powdered Metal Steel
Pistons: Hypereutectic Aluminum
Camshaft: Hydraulic Roller Tappet
Cam Lift: .460” Intake / .481” exhaust
Cam Duration @ .050”: 196 deg. Intake / 206 deg. Exhaust
Lobe Separation: 109 Degree
Cylinder Heads: Vortec Cast Iron, 3/8” pressed-in rocker studs
Combustion Chamber: 64cc
Valves: .194” Intake/ 1.50” Exhaust
Rocker Arms: Aluminum Roller, 1.6:1 Ratio
Valve Springs: 10212811
Balance: External
Maximum GM Recommended RPM: 5500
Ignition Timing: Base 10 degrees BTDC, 32 degrees total


Engine Includes:
• Fully GM assembled long block
• Chrome Steel Valve Cover with Chevy Bowtie Logo
• Distributor, Plug Wires and Spark Plugs
• 12498032 GM Performance Fuel Injection System
• 14” Manual Trans Flywheel
• Oil pump, pick-up and oil pan
• Cast Iron Long Style Water Pump
• Passenger Side RH Oil Dipstick and Tube

Warranty:
General Motors limited 2 year / 50,000 mile parts & labor warranty. Click on Document tab above for full details.

Re: Vortec Advice
 

looks like a vortec long block with a cam swap and 1.6 rockers to me..

Re: Vortec Advice
 

https://www.summitracing.com/parts/cca-4609/overview/

Re: Vortec Advice
 

photo is to small to tell how they are getting it not to spin..
gold plated part.. only 120 bones..

Me thinks I'd block off plate and electric..

Re: Vortec Advice
 

I might still do that...

But now I have a new cam on the way. ;)

Re: Vortec Advice
 

The slot in the pushrod is engaged by the threaded rod that goes in through the front of the block. But yikes, I agree, that's not a cheap solution. A normal fuel pump just needs a regular pushrod. Not a roller. Keep it simple and safe.

Re: Vortec Advice
 

The bronze tipped pushrods are less $$. Are you using a stock FP pushrod with a roller cam?

Re: Vortec Advice
 

I ordered a bronze-tipped rod just for cheap insurance.