[Galaxian80]

Ok. Right now my RC is sitting and will be for the next 6 months. In those six months, I plan on building up the engine, painting it, and putting a nice exhaust on it. For my engine build up, I plan on taking my buddy's 78 360 and buying a rebuild kit for it and taking the heads from my 90 TBI and having them ported and polished. As for the intake, I was thinking of getting an Edelbrock Performer intake and having an adapter plate made up from my ex's dad (he is good at that kind of stuff). Does anyone see any problems I could run into with that? Also, I was wondering about hooking up a little boost of NOS. I saw the Top Shot System that I think would work for a 75 to 150 hp boost. But I was also thinking, if the 4 bbl intake with an adapter plate would work, would I be able to get a NOS system made for a Holley and put it under the adapter plate? I have never done anything with NOS and don't know the do's and don'ts. What else can I do with my next 6 months?

 

[chrysler300le]

i see several problems. Are you going to stay with TBI? If so forget the 78 block. Forget the nitrous (I prefer the term nitrous over the ricerboy NOSS) TBI computers can compensate for a ported out head engine with alot of mods. 78 blocks don't have the neccesary stuff for rollar cam. I would really stay with the rollar cam for TBI. The whole TBI system doesn't have enough fuel compacity to keep up with adding Nitrous. I haven't payed attention to the latest stuff for nitrous but it use to be that you had to add more fuel with the nitrous or it would be too lean and cause your engine to blow up. With all the kits they have now days i'm not sure what you can do. I just don't see it working very well with TBI though.

 

[Galaxian80]

I am planning on staying with the TBI. Can't I get a roller cam and put it in the 78 block? About the heads, the guy I bought it from said he had some head work done to it years ago, but since then, put 200K miles on it. I've put about 50K since I've had it. It still keeps up with all newer trucks and I've stomped every truck I've raced so far except for the 454 Chevy and a big block Dodge with one hell of a cam. I wanted to take the heads to a shop and have them do what all they can to get some HP out of them. The NOS is just an idea for some quick HP, not a permanent idea.

 

[chrysler300le]

You can get a rollar cam in a 78 block but not with stock parts because it don't have the taller lifter bores and the mounting pad cast into for the spider plate that holds the lifters in place. Your pretty limited with TBI unless you have the computer reworked.

 

[deuce6911]

Just curious, why is a roller cam prefered with TBI? It seems to me that an ordinary flat lifter cam would work fine.

 

[TheRamChargerMan]

Well, here's an example...a roller cam with basically the same lift as my flat tappet, makes, according to the dyno program I have (not accurate, but good for comparison, as the errors are consistent), roughly 65 hp more.

Does that answer your questions

And using a roller lift on a 78 block will get expensive.

 

[Runin' With The Devil]

I agree with most of the posts that have recommended staying away from Nitrous with the TBI. Not saying it can't be done with the help of JET Performance, (Custom computer), and a gazillion dollar supplementary fuel delivery system, but it could get very expensive very fast. 1/2 the money could be spent building a stout 360 TBI motor that would put up some pretty impressive hp and torque numbers.

I just installed a custom built '90 360 TBI motor in my '90 RC. I've been planning this for a couple of years and have done a lot of research.

It all started with me building up a 318 TBI motor, (With everything available I could think of to make it a hotrod.) Headers, TBI adapter plate that allowed me to run the TB on an Edelbrock performer, .443 Magnum roller cam, (Mopar Performance 300 hp service cam and lifter kit), headers, dual exhaust with hi flow cats and mufflers and K&N air filter. Later I added 360 injectors and a SBEC computer from a 360 1 ton pickup, (1990).

The performance improvement was phenominal in the 318, with just the addition of the 360 injectors and 360 computer!

I've since installed the new 1990 366, (.030 over 360), with 2.02 SS valve heads, gasket and port matched to the same Edelbrock Performer intake, using my adapter plate. I installed a 50 state C.A.R.B. legal custom ground Crower roller, .456 / .466 lift, (advanced 2 degrees), and 9.6:1 hyperutectic pistons, and the stock 360 TB. The motor dynoed at 355 hp and 400+ lb of torque, all at a user friendly 4800 rpms.... The computer is from the stock 360 1 ton truck I mentioned.

This thing is a beast! When Crower machined the cam, I had them add the length to the front snout so I could install the older style eliptical for a mechanical pump, (if ever decide to run a mechanical pump and carb), however I will run the TB to get through emissions. I mounted the O2 senor in the driver's side collector via a weld in bung ftg. from Jegs.

I kept the 318 TB in case I need to de-tune it and lean it out if I have any problems passing emissions with the 360 TB, here in MD.

(Incidently, I have pictures available of the side by side comparrison of the throttle bore sizes between the 318 /360 TB's. Big difference.) I'd be happy to post them or email them to anybody that is interested.

I'm running 8.5 deg. advance for break in and right around 35 deg. total between 2800 and 3000 rpms. This thing really storms! (I'm running 37" SSR's and 4.56 gerars.)

The trans was built to Cummins specs; (A-51, using an ATI fully rollerized 22-2300 rpm stall speed convertor.

I just wanted to let you guys know that these '88-90's TB motors can be made to run, if you're willing to get a little creative.

My next improvement will be to up the fuel pressure a couple of psi, (once I find a compatable aftermarket regulator or figure out how to mod the factory one). (Ideas or suggestions would be appreciated if anyone has done this already).

Let me know if you want to see any photos for ideas you guys could use, if you're interested.

This got a little long, but I felt it was important to give these TB equipped motors the credit that they're due.....

Dave

 

[s ǝoɾ]

i think with these engines you can take a small tap and tap the atmospheric reference line. basically higher air pressure pushes the diaphagm in to allow pressure compensation. you can use a small screw and thread it in and push the diaphragm farther in. dunno if this trick works on dodges.

btw, i ve mentioned this before, but you might check out holley projection. not a conversion but service parts. that includes the larger injectors (454 had tbi) plus that simple adjustable computer they sell to convert gm tbi to "projection" the computer is a replaceable service part that is only like $200 and allows adjustability.

here are a few more tuning tricks to manipulate fuel curve (not most refer to gm tbi which just happens to be made by holley)

http://www.cfm-tech.com/oxygen_sensor_tuning.htm
http://www.cfm-tech.com/gm_tbi_fuel_pressure.htm
http://www.turbocity.com/default.php?cPath=16_27_30
http://www.turbocity.com/product_info.php?cPath=16_27_42&products_id=412
http://www.turbocity.com/product_info.php?products_id=141
http://www.turbocity.com/product_info.php?products_id=437
http://www.jegs.com/cgi-bin/ncommerce3/CategoryDisplay?cgmenbr=361&cgrfnbr=668