Ramjet 350 intake on a 5.7L vortec

[Jaisuns]

I just did a 5.0 to 5.7L swap in my 97 x-cab and was wondering if anyone here had done a Ramjet intake swap before? The TB on the intake looks alot like a vortec....and i heard the sensors used on the intake are also off the vortec engines. Hopefully that will be my next project.

[thekl0wn]

I'm interested in this myself, but not real sure on any info. I did read a post that I believe Pauly wrote, where he talked about using the RamJet intake on the Vortec.

[Lextech]

The throttle body will bolt right up but, the accelerator and cruise attachment is 90 degrees off, so you have to rework that or use a throttle body off of an LS type engine (4.8 5.3 6.0 or whatever). These L/S bodys' are also a little bigger bore. You will need to clearance the rear inner bolt hole area of the A/C bracket. You will need to persuade the A/C lines up to clear the throttle body. You will need to change the BIG injector connector into 8 individual injector plugs, and put a 45 degree elbow on the coolant boss on the passenger side of the intake by the throttle body to clear the cable arm, that way you can use the stock heater hose and connector. As far as I can remember that should do it.

[Pauly]

the ramjet intake ona L13 or L31 Vortec 350 or 305 will work really well. This lets you get rid of the stock 19 lb/hr poppet injectors that the stock Vortecs come with.
I did something a little different, I used the GM Vortec Marine Intake.
http://www.sfatek.com/images/efi.jpg

This intake drops right in place o fthe stock truck intake, all the injection stuff is ouside of teh intake, the insid eof teh plenum is MUCH smoother and less contoured than the messy L31 truck intake.
Here is apic of the Marine and truck intake next to 1 another.(scroll down).
http://www.performancetrucks.net/for...d.php?t=356743

I chose the Marine intake overteh Ramjet because the marine intake alows you to use the stock cruise control stuff and air intake systems.
i got a used MArine intake kit MUCH cheaper than I could get a BARE new Ramjet intake for. I paid $750 US complete for a Marine Intake with injectors (28 lb/hr).

Goodluck, post back with any questions.
peace
Pauly

[thekl0wn]

Thanks Pauly & Lextech. I'm not sure about Jaisuns, but it answered some lingering questions I've had.

[Jaisuns]

Ive looked into the MPI intake...and found very little info on it, other than from your previous posts. When i priced the system it was outrageous like $3k+, compared to $1400 for the Ramjet. Id much rather the marine intake, looks like it would be alot easier to install. You know of any place to get a used system?

Heres another nice upgradefor the vortec intake : )
http://www.offshoreonly.com/esvon/page-8969.html

[airdeano]

the marine manifold is a ok substitution, but has similar affliction
of the truck manifold, low roof that destroys the air inlet/intake port
angle and tight plenum volume. the ramjet 350 manifold is a downward
straight shot to the intake port.

airdeano

[Lextech]

The Ramjet is very expensive if you purchase the entire manifold assy. I think I paid around 500.00 for the bare intake( I would need to look through my stack of receipts to be exact). I used salvage yard fuel rails off of an LT1. I think I paid around 25-30 dollars for them, they work with VERY LITTLE modification. You need to take off the metal crossover pipes on the ends of the fuel rails and tap the ends to thread fittings into. The Marine intake seems to be a very good choice also, it just depends on what your ultimate goal is for the engine. As already stated the Marine is sort of like a dual plane and the Ramjet is a smallish tunnel ram.

[Bigtown88]

Got any pics of your setup Lextech?

[98bagsilverado]

I've done a ramjet intake on my 98 silverado.



That setup went 12.84 @ 106.5

It didn't cost a lot. and it is well worth it.


Shawn

[thekl0wn]

Originally Posted by 98bagsilverado

I've done a ramjet intake on my 98 silverado.



That setup went 12.84 @ 106.5

It didn't cost a lot. and it is well worth it.


Shawn

NICE!

Any estimates on what you guys spent on your intakes...Total?

[Lextech]

Shawn--- Very nice/clean install, mine should be very similar except with 2 small T3 turbos. I don't know how to post pictures, I don't have any of the intake on yet anyway. I do have pictures of my homemade turbo headers with turbos on. Right now I am building the intercooler, using 3 Saab cores joined together. I will be purchasing Tunercat to try to tune it. I still have to do the fuel supply. I will probably use 2 internal pumps joined together outside the tank with a Y connector and -8 lines to the fuel rails. I was thinking of turning on the second pump at about 4 lbs of boost using a Hobbs switch and relay.

[Pauly]

I paid $700Us for my Marine intake that came with: upper, lower, injectors,(28#) IAT, MAP, fuel rails(stainless), fuel pressure regulator, marine t-body.

It came with everything that is on the intake in this picture http://store.summitracing.com/defaul...h.asp&x=27&y=5

This intake was designed for both 350 and 383 cube engines. Its intake ports are slightly larger than the stock L31 truck intake, I personally measured them. The intake runners are only 8" long.

The Marine Intake is over $3000US if you buy it new.
http://www.mercruiserparts.com/Show_...+and+Fuel+Rail

Here is the Marine Intake right next to an L31 truck intake.(scroll down, 2nd last picture) thereare also some excellent comparitive poppet spider and multec spider pics.
The Marine Intake looks very similar to the stock truck intake, but I tell you that there perfromance is quite difference. Mytruck has never pulled as hard as it does form 3200 to 5800 rpm as it does with this intake.

With the vertical facing Marine Intake the air is allready heading in a downward fashion and spirals around in the intake then heads down into the intake port runners. With the Ramjet, the airflow is travelling in a hrizontal direction thru it horizontal t-body, then it has to make a 90 degree turn down to enter the intake ports.
The Ramjet does have shorter intake runners though.
P/N 12489371 350 RamJet Manifold is teh pn for the bare intake alone. This costs $800CAN.
The 12498032 is the Ramjet fuel injection kit, comes with, coil, intake, distributer, knock sensor,fuel rails, t-body,injectors, map sensor and FPR.
The stuff that would be needed for the truck swap totals $2230CAN. This price doesnt include ALL the above listed stuff, just the stuff that is need for a truck app.

In my opinion, the Ramjet, MArine swap is very usefull for those who will be using a super charger turbo or dry nitrous system or larger stroker engines swap is to ube able to use larger replaceable fuel injectoirs and to get away from the stock 19 lb/hr poppet and MPFI spiders.
Simply swapping on these intakes for power gains from a stock L31 is a very expensive dollar per hp proposition.

The folks involved in out MArineIntake project will have some dyno numbers and track times soon. The supercharged guys are reporting nice SOTP gains., and I am getting good results onlystock longblock NA setup. There are now only 3 of us with teh MArine Intakes installed, mine on a Vortec 350 and 2 of them on Whippled 350's. The guy with a Vortec 383 took his off as he is selling the truck

Finding a used MArine or Ramjet intake is the key tokeeping costs down for both projects. I completed my marine swap for under $1000US including PCM tuning. You need to change the injector fuel flow tables to correct for whatever sized injectors you are using. As long as the injectors are high impedance, the PCM will drive them.

the guy who is selling the MArine intake kits is selling them for $750US. All you need to buy to install it is fuel feed lines and intake gaskets. This guy even machines in the front hole and thread to allow the stock Vortec cooling hoses to be used. He is a very straight up guy. he even sends you colour coded wires that matches teh stock GM injectors harness, weatherpack injectors connectors, a wiring diagram for thevortec injection harness, t-body gaskets, various fittings.

He has just received 2 or 3 more marine intakes. If anyone wnats 1 or more info directly from him. please PM me and I will put you in touch with him through the proper channels. I believehe has sold 10 or 12 of them.

the marine intake is much better than the stock L31 setup, the plenum volume is increased and flow improved simply from removing all of the L31 Vortec fuel popets, feed lines and fule pressure regulator from the plenum. the inside floor of the plenum is flat compare dto the horribly contoured floor of the L31 truck piece.
if you need an adjustable fuel pressure regulator, an AFPR from an LS1 Vette with the return style fuel system will work, but noone so far has used 1, or needed 1.

98bagsilverado has a killer setup with his Ramjet intake on an L31 engine, finally the L31 can post some good numbers.
peace
Pauly

[Jaisuns]

Its prolly gonna take a few months b4 im ready for the intake swap.I just did the 5.0-5.7 swap in my truck and am still having a few prob's. Just got my y-pipe in today (had to cut my old one out) and drove it for the very first time..its giving a VSS code now..gotta straighten it out by next Wednesday, we are going back to South MS. Gotta change from mech to carpenter lol. Hopefully ill be ready for the swap this summer. Thanks for all the info and it will come in handy..soon i hope :)

Ill prolly go with the marine if your friend can get me one Pauly,(Pecos right?) $750 is awsome..compared to the ramjet. For all im going to use it for the ramjet would prolly be overkill. Thnx again

[Boosted-Z71]

Theres pics of my marine / whipple setup in my gallery. No comparison to the stock intake.

Boosted

[98bagsilverado]

i didnt have to pay that much for my intake, i got good deals on everything and had the machining done by a buddies grandfather. i think i have about $2000 into the ramjet intake. now my engine and trans. is out of my truck and putting better things into it. like a 4l80e trans. f-1 procharger, edelbrock e-tec 200 heads, arp studs, sce head gaskets.

We'll see how much power the stock bottomend can handle.