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Discussion Starter · #1 · (Edited)
hey guys at Smokinvette - its been a while. was looking at my last post - was 2010. Not sure where you guys are with your cars right now, probably way ahead, but I finally got around to thrashing on mine. I did quite a bit of work on the motor and it's finally getting fun to drive. I know I have some work to do yet but I'm sure as I continue you will weigh in with your thoughts as you did last time. I do have to thank all of you who responded to my questions: It helped me a lot. But... I do have more questions, but first I want to figure out how to upload pictures/Users/leodagostini/Pictures/iPhoto Library/Masters/2013/06/10/20130610-220214/IMG_2269.JPG if there is a picture showing this is where I am so far. Of course I will want to explain what has been done. :cheers::cheers:
 

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Discussion Starter · #3 · (Edited)
1984 Corvette L83 Crossfire Injection

I have to start by saying - I love this car. Corvette department missed a year of production sales because and the first model year of the C4 wasn’t released to the public until sometime in 1984. They sold 51,547 units of various configurations but the only engine that was available was a leftover from the 1982 which was also the only C3 to have this motor… the infamous L83. www.vettefacts.com/C4/1984.aspx

‘Bit about me – 4th year apprentice mechanic and have built a few race small blocks (no knowledge of fuel injection what–so-ever when I started this project so this was a big step for me but up for a challenge) Worked in speed shops and drag raced as a kid. (Cayuga just incase anyone is wondering). I Built an 11second bracket car, raced to no success but had a great time doing it. Friendships, parties, great culture to grow up in. I was looking at the last threads we were posting was back in 2010… time flies.

Hell bent on finding horsepower for this Corvette without spending a ton - I found really cheap bits and pieces to convert it to carb. I really wanted to keep the cool looking CFI but if I didn’t use any of the carb setup I could resell it all. It was a good del and couldn’t let it go. The age of the internet has completely changed the way we buy and sell parts. Thanks KIJIJI.

If you want to make this car go with little effort just spend lots of money on a Fast or Holley EFI on a dual plenum intake and some aftermarket heads and dump the stock ECU, intake and TBI’s. I didn’t have this knowledge before I started and only knew old school stuff so I collected old school parts, I wasn’t in a rush as the car drove perfectly in stock form with its 205 hp L83 but always knew in the back of my mind this 3000lb car should be at 350hp plus. I bought it with less than 50,000 miles and saw that I wouldn’t have to spend much on the body, interior or suspension, etc. I could concentrate on just making power.

The Engine Hardware

Stock block, reciprocating mass, oil pump and pan. New – double roller cam sprockets and chain, Lunati flat tappet hydraulic lifter cam (.490 lift/240*@.050 duration/112 LS on stock 1.5 rockers. Ported 1987 L98 heads (58cc chambers/11.5:1CR) with 3/8” screw in studs, guide plates, Stock diameter Bee Hive ovate springs and teflon seals.

To get a base line for this motor and to see how the ECM would react to the changes, I initially made no changes to the CFI system other than porting as much out of the intake as I could. I did not remove the EGR tunnel as I did not see this as an obstruction to the flow relative to the TBI position and frankly wasn’t worth the effort. Why? Because all of you who posted that virtually nothing could be done to open the runners up enough to increase the entire runner length equally, I found to be completely accurate. No matter what I do the rest of this build it will only flow as much as the narrowest part of the runners will allow it to. At best you can get it to about 2/3rds the size you can get the head side opening of the manifold. (The RENEGADE just by looking at the pictures of the runners seems to have addressed this issue).

Anyhow – I wanted to see for myself – so bolted the entire stock top end back on to the block including the stock ignition. I took out the guts of the AIR Pump, removed all the periphery tubing right to the exhaust manifolds and now the pump serves as an idler wheel. I hole saw cut holes in the valve covers to accept Moroso oil separator breathers on each bank and plumbed them onto the 5/8” smog vacuum tubes already mounted on the stock exhaust manifolds. The PCV valve was removed from the line as there was no longer a place in the valve cover for it. Plenty of vacuum to create negative crankcase pressure and limit oil leaks. It seems to work well. I haven’t seen this done before; it’s easier than welding on a bung and a lot less plumbing.

After examining the 1984 stock exhaust manifolds I determined it was not necessary to install headers as the openings were quite generous and unrestricted contrary to a set of ’87 L98 exhaust manifolds I have that seemed as though the guy on the assembly line said let me weld these bitches almost shut.

I emptied the cat and installed a BB Cat Back exhaust system. A very nice flowing total exhaust for the money spent. (No emissions to worry about where I am)

Motor started first turn and broke in the cam at about 2000/2500rpm for about 20 minutes. I had replaced the T-stat with a 160* version to keep it cooler. I also replaced the fan switch with the matching version. Coolant temp averages 185* and oil temp around 200.

Attitude Changes

After some tuning which included balancing the TBI’s (with a feeler guage) and playing around with the Throttle Position Sensor and idle screws and timing I have a very drivable car. Very cam-lumpy idle at 900rpm. Instant start every time. A little rich at idle and still has a bit of a stumble at idle also. It pulls very hard compared to the 205HP stock mill. I believe I have increased torque by close to 100 over stock as it breaks the tires loose at will in first and second from 2000rpm, however, as suspected, does nothing over 4500RPM.

Overall Review at Stage I of the Build

To this point in the build I am very pleased with the power over stock and now the car is fun to drive. I get a high pitch sucking noise at WOT over 4000rpm like the heads want to suck the TBI’s right through the intake runners.

What’s Next

There are a couple of parts I am waiting for. 1) a Racetronic 40+psi fuel pump. I believe the stock pump could be tired and pumping the minimum 9 of 9 - 13 psi it is rated for. I may get 13 to 14 psi from the stock regulator/compensator. I may change the regulator springs or was thinking of balance plumbing with Aeromotive 13301 regulator. It feels as though it can’t keep up to the demand. (yes… that intake?). 2) I am also installing a mechanical advance MSD 6AL Box and distributor to over ride the ECM timing of the GM HEI. At present I am running 94 octane and there is no pinging unless I manually crank the distributor around to about 25+* advance. This tells me the fuel mixture the O2 sensor is reading or the extra noise coming from the exhaust manifolds or something is not allowing the distributor to advance. Another thanks out to KIJIJI for good used parts. There may be a point where I may have to give up on the stock CFI but the education has been worth it.

This is a fun, easy car to work on and play with. I could have even changed the crank right from the jack stands without lifting the block. Recommended for all ages.

BTW – I just want to send a thank you out to all of those that helped me get to where I am on this build. I think we had some good threads judging by the number of reads on them. I’m always open to suggestions and looking forward to hearing back and will try to keep you posted. I took some pic’s along the way and will post when I figure out how to.

Just remember – I have a carb and intake ready to install if I can’t get this CFI to smoke the tires at will.
 

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Discussion Starter · #4 ·
Look in our site issues section. It explains how to :thumbsup:upload pictures
So in order to place a series of pictures in a post I have to upload them first into the Gallery?
 

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Discussion Starter · #6 · (Edited)

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Discussion Starter · #9 ·
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Finally figured out the picture posting Lethal (harder than building a motor)
 
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