Vehicle Owner

Member ID: NixVegaGT

Location: Roseville, MN

Vehicle Info

1973 Chevrolet Vega

Bought: Jan, 1993

Bragging Rights

  • 1/4 Mile0 sec @ -1 mph
  • 0-600sec
  • Top Speed-1mph
  • HP-1
  • Weight2360lbs

Major Upgrades

  • turbo
  • nitrous
  • bore increase
  • port and polish
  • supercharger
  • extrude honed
  • stroke increase
  • engine swap

Modifications

Performance Parts

Interior

Ratings

    • Currently 4.0/5 Stars.

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Last updated: Sep 30, 2009

Hits: 34,898

Nicolas’s Chevrolet Vega
“DogBoxx”

  • Currently 4.0307692307692 /5 Stars.
39 guestbook comments

'73 Vega GT All Aluminum Wildcat 355 Project

Contents:
Page 1: Engine Block prep

Page 2: Head mods

Page 3: Induction/Exhaust

Page 4: Engine Assembly

Page 5: Front Suspension Mods

Page 6: Rear Suspension/Weight Transfer Mods

Page 7: Rust Repair and Undercarriage prep

Page 8: Frame Rail fabrication/Unibody support

Page 9: Body Mods

Page 10: Transmission Mods
Page 11: T5 Rebuild
Page 12: BMW Radiator Swap

Engine Assembly:

My machine shop, Wagamon Brothers , finished the machining and customization of all the separate componants of the engine project:

The engine was blueprinted; Cylinders to pistons, Crank mains to block mains, Rod journals to connecting rod big ends, Cam to bearings etc.

As you've read on the previous pages the heads have been modified for the larger valves and the cylinders have been pinned. The last pieces of custom work to be done was fit the Buick pins to the Chevy rods and Ford pistons.NixVegaGT's 1973 Chevrolet Vega Then I had the whole assembly balanced. We found interference with the crank and the pistons so I had them releave the crank where there was interference and rebalance the crank. They also trial fit everything to check clearence for bearings and rotating assembly.

The connecting rods are from a '69 Z28 302. The beams were shotpeened and polished, and the pistons were deburred and releaved for the crank interference. The big ends had 100 thou removed to fit the crank journals, and the smalls were honed for Buick pins.
NixVegaGT's 1973 Chevrolet Vega NixVegaGT's 1973 Chevrolet Vega

It wasn't cheap: $4972.57 Now that I have all the pieces ready to assemble. Since I had the assembly trial fit I don't need to check the clearences so things should go pretty quick with the short block. Then will come the front cover. I expect some problems there...

Good new for me! I found an adjustable roller rocker for the Rover/Buick on Summit manufactured by Harland Sharpe. It was listed as a stud mounted system so I called Harland Sharpe directly. I spoke with Randy Sr. He was a huge help. The best part is I got the setup for $130 less than on Summit!! I'll post some pix when the system arrives.

Here they are! Here's a pic of me eagerly opening the package:
NixVegaGT's 1973 Chevrolet Vega NixVegaGT's 1973 Chevrolet Vega

I started assembling the pushrod cup screws. I've been waiting to buy these for over a year now. It's pretty cool that I could finally afford it.

NixVegaGT's 1973 Chevrolet Vega

 

I'm putting the deckheight stats in here because I continually forget and go to work out the math over and over.

Piston comp height is: 1.585"
Piston dia: 3.7395"
Wrist Pin dia: 0.9122
Piston head vol: 1.5cc

Connecting Rod length: 5.7"
Big end dia: 2"
Small end bored to: 0.9122

Block deckheight: 8.96" stock
Block decked: -0.005 (8.955")

Rotating assembly height: 8.985"
Pistons 0.030 above deck

Head vol: 54cc

Engine Mock up

I assembled the empty block with the heads and oil pan to mock up the engine in it's final placement for engine mount fabrication. I started by installing the ARP stud kit I got for the heads.NixVegaGT's 1973 Chevrolet Vega NixVegaGT's 1973 Chevrolet Vega

NixVegaGT's 1973 Chevrolet Vega I had the rare opportunity to see what the chamber looked like from the cylinder side. Here's a pic. It's not that easy to see by the pic but the edges of the chamber fits right to the cylinder walls. It looks like I will not have any problems with valve shrouding with the larger valves I installed.

NixVegaGT's 1973 Chevrolet Vega I just slapped on the grungy valve covers and the single plane intake I bought from Australia. What I hadn't noticed was the intake is setup to be level with the engine. The Buick/Rover is usually mounted with the engine rotated back about 3-5º. The Edelbrock performer 3.5 may be a better choice. We'll see.

NixVegaGT's 1973 Chevrolet Vega So I got the engine/trans empty (no rotating assembly or internals on the T5) in place. It was really gratifying because it's been years since the engine has been in it. So my plan is to move the engine back a couple inches. I think I can get it to move about 2" before I get to the firewall. Since the distributor is located in the front of the engine I don't have to worry about interference there. The only problem is the heater core then. I will have to make a custom, smaller one to fit if I move it back. That's what I'm going to do though because I'm fixated on moving it back

NixVegaGT's 1973 Chevrolet Vega NixVegaGT's 1973 Chevrolet Vega

 

You can see here how far away the engine is mounted with the D&D kit. That's OK but I need all the weight distribution I can get. I'm really close to 50/50 and I think moving the engine back with get me there. SO I used a soapstone to mark where I would need to relieve the firewall to make room for it.

NixVegaGT's 1973 Chevrolet Vega NixVegaGT's 1973 Chevrolet Vega

 

Here's how it turned out! Sweet! It took some planning and manipulation of the engine position with a jack and the hoist to get it level and square. What's interesting is the engine is mounted about 1" to the right side. I guess that makes sense taking into account the pinion position in an equal length axle housing.

NixVegaGT's 1973 Chevrolet Vega NixVegaGT's 1973 Chevrolet Vega

 

I had to massage the trans tunnel a little. I ended up mounting the engine about 1 1/2" lower than stock so that made a bit more room in the tunnel. The stock Rover/Buick is mounted tipped back at about 7º. I lowered it to about 4º or so. I'm pretty psyched because I gained a crapload more room for the radiator than I expected. I ended up with about 3 1/4" between the water pump and the radiator. That's with the thicker core radiator too. That's a lot for our cars since we are usually pretty excited about having an inch to spare. LOL.

 

OK I'm up to actually assembling the engine. I started by removing the protectant. I thought I'd use the old fashioned hot soapy water method. It was working pretty well. I thought I know I'll use the Dishwasher! BAD IDEA! I ended up having to remove a bunch of surface rust to remove! DUMMY! Here's some pix of my stupidity:

 

NixVegaGT's 1973 Chevrolet Vega      NixVegaGT's 1973 Chevrolet Vega

 

Soapy water, good. Dishwasher. BAD!! LOL! OK well after I spent about two extra hours after trying to save time I was ready to assemble the engine. I started by setting up the rear main seal adaptor from D&D fabrications that adds a provision for a labyrinth rear seal. It uses four rivets in the back of the block to secure the upper half of the seal housing. I also added some high temp RTV between the block and seal housing to secure it. In the main cap the job is to drill a hole through the top of the main cap and into the body of the seal housing. Then drive a rolled pin into the hole. I filed the rolled pin flush and then turned it over and draw filed the seal housing flush with the main cap's mating surface.

NixVegaGT's 1973 Chevrolet Vega        NixVegaGT's 1973 Chevrolet Vega

Then I setup the main bearings and gingerly lowered the crank into the block. Here's a shot of that and a close up of the seal in place:

NixVegaGT's 1973 Chevrolet Vega        NixVegaGT's 1973 Chevrolet Vega

The next thing I needed to tackle was spark distribution. I've been avoiding this because of the potential complciations in running E85. I need to run a much higher spark advance to optimize the fuel propagation. I did some research of potential solutions and found something that will work perfectly. A couple of guys on my BritishV8.org. forum were running the Ford EDIS (Enhanced Distributorless Ignition System). I thought I'd try to learn something about it. It turns out to be a very straight-forward and simple system. The module uses a wasted spark system meaning it fires power one cylinder while simultaneously firing on the exhaust of the cylinder 180º from it. Here's a couple pix:

NixVegaGT's 1973 Chevrolet Vega     NixVegaGT's 1973 Chevrolet Vega

It looks complicated but it is actually very simple. The trigger-wheel and sensor at the lower right replace the distributor points and is mounted on the crank like the pic to the right of a buddy's setup. The module, lower left, handles firing distribution to the coils above. The benefits are it's simple and robust; There is no need for typical maintainance, and the spark is wide and strong because of the individual coils. I'm controlling the spark advance with a Megajolt Lite Jr. It uses a 10x10 table with fields to enter the spark advance based on RPM and load. EASY and accurate. The last hirdle was coming up with a way to retain the distributor gear because it drives my oil pump. I decided to chop up an old distributor I had laying around to experiment. It turned out to be really easy. In the pix below I started by removing the gear and shaft from the housing. Then I chopped the housing and shortened the shaft.

NixVegaGT's 1973 Chevrolet Vega        NixVegaGT's 1973 Chevrolet Vega

Then I removed the bushing from the head. Then I drilled and pressed in the bushing into the top of the stub I had left over. Here's the finished product. FUN!

NixVegaGT's 1973 Chevrolet Vega       NixVegaGT's 1973 Chevrolet Vega

I built the circuit board for the MegaJolt EDIS controller. It was fun to build. It took about 2-3 hrs. since I was being extra careful. Here's a pic before and after. The toughest part was the surface soldered extra tiny componants.

NixVegaGT's 1973 Chevrolet Vega         NixVegaGT's 1973 Chevrolet Vega

I finally got to finishing the fight I've been having with my engine/piston/valve clearance. First thing was the piston to head clearance for quench. I had only about 12 thou for quench clearance and that's not good so in order to retain the CR I desided to recess the head decks to get it. That way I could keep as much Cc as possible. Here's a pic of the recesses. I'll upload a better pic soon:

NixVegaGT's 1973 Chevrolet Vega     NixVegaGT's 1973 Chevrolet Vega


I also had to notch the pistons for valve clearance. I guess this is what people go through when building a performance engine. I could only get one cutter from Isky that was sufficiently small enough to do the exhaust. It was also about 50 thou bigger in dia than the intake. Not quite big enough typically I figured I'd mount the head right at deck level and cut at that level. That should give me a little more side clearance because of the valve angle. I never realized how shallow the valve angle is on these heads until now. 8.5º! WOW. No wonder they flow so well. Here's what the masking looks like for the notching.

NixVegaGT's 1973 Chevrolet Vega          NixVegaGT's 1973 Chevrolet Vega

Here's a couple pix of the Isky piston notching tool. It worked really well and was easy to use. It's supposed to be used with a tap handle but I used a really slow moving drill.

NixVegaGT's 1973 Chevrolet Vega           NixVegaGT's 1973 Chevrolet Vega

I slapped on the heads, valve covers, and intake to give myself inspiration. It looks pretty cool. I was thinking about ditching the 340 cover labels but maybe I'll keep them. The Wildcat 355 was a 340 afterall.

NixVegaGT's 1973 Chevrolet Vega

Guestbook

Displaying entries 1-5 of 39

hoffbug  

Posted by: hoffbug

10/20/2009 04:08PM

dude.. you have to let me know when you are going to dyno.. I want to come with!

CELICAHOLIC  

Posted by: CELICAHOLIC

09/30/2009 12:14PM

HI,You are making a great job with that ride, don't give up. 5 stars for you.

classicplymouth  

Posted by: classicplymouth

09/23/2009 03:23PM

Check out this local car show!!! www.rockabillykitten-mn.webs.com/carshows.htm

VEGAVAIRBOB  

Posted by: VEGAVAIRBOB

09/16/2009 10:52AM

5 stars for ya..nice work. i posted some new photos of mine...

FLUFF1111  

Posted by: FLUFF1111

09/15/2009 12:58PM

very nice vega 5 stars 2 U!!!!!!!!!! come check out "nikita"

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Vehicle Owner

Member ID: NixVegaGT

Location: Roseville, MN