Craig Roush's 1958 MGA with GM 3.4L V6 Engine
as published in BritishV8 Magazine, Volume XVI Issue 2, October 2008
Owner: Craig Roush
City: Longmont, CO
Model: 1958 MGA
Engine: GM 3.4L V6
Transmission: Borg-Warner T5 5-speed
Conversion performed by: owner
|Engine:||GM 3.4L V6 with non-feedback GM Varijet carburetor on stock manifold
(390 CFM with manual choke). Comp Cams camshaft (#260-H) with Crower
lifters, springs, and retainers (kit #84008), and Comp Cams roller
rocker arms (#1413-12). Home-made fiberglass air cleaner with cold-air
|Electrical Mods:||converted to GM alternator and 12 Volt negative ground using HEI
ignition with remote coil. Tachometer modified for HEI 6 cylinder,
and speedometer rebuilt, both by MO-MA in Albuquerque, NM.
|Cooling:||modern crossflow radiator mounted on rubber-cushioned brackets just
forward of original position. Reserve coolant/expansion tank and
over-flow tank, both owner fabricated. Electric cooling fan (pulling).
|Exhaust:||owner fabricated headers, made from a "Headers by Ed" kit.
|Transmission:||Borg-Warner T5 5-speed. Stock Flywheel and pressure plate from a
3.4 liter 1993 Firebird with aftermarket clutch disc, and Howe
hydraulic throw out bearing. Master cylinder sleeved to accommodate
Howe system. Custom driveshaft by Driveline Services in Boulder, CO.
|Rear Axle:||stock MGA (4.56:1).
|Front Suspension:||stock MGA with MGB front sway bar.
|Rear Suspension:||stock MGA.
|Wheels/Tires:||currently using MGA 1500 steel wheels on the front, and MGA 1600
steel wheels on the rear.
|Body:||"LeMans" style front valance from Auto Vintagery in La Jolla, CA.
|Performance:||haven't quantified it yet, but it's quick and "fast enough"!
|Completed:||1999. Driven about 5000 miles since completed, as of September 2008.
|Comments:||This car has been a project ever since I acquired it as a rust bucket
back in 1973. It had had a number of paint schemes already by then, and
was finally brought back to stock red in 1995. Then it dropped a valve
on the conglomerated 1500cc / 1622cc engine.
The conversion process began with a trial 2.8 liter empty block from "Pull & Save".
The motor mount and transmission mount system was just an adaptor plate set-up in front, using the stock rubber mounts and an angle iron "extension" with an adaptor to support the tailshaft housing. to line up.
I wanted to keep the body looking stock, and that was easy to do by using a carburetor. A throttle body fuel injection system is in the works though, along with a 3:89:1 ratio rear end.
The most time consuming part was working out the header system. The left side had to snake around the steering column.
It's almost time to do a full re-paint, now that the last of the mechanical issues are almost dealt with.
GM 3.4L V6 with a GM Varijet 390cfm carburetor.
Cold air induction with a remote box-type air filter.
Stock MGA rubber mounts were used with an adaptor plate set-up.
GM Varijet 390cfm carburetor on stock manifold.
Clever homemade fiberglass air cleaner/induction system.
Stock brake and clutch master cylinders, and windshield wiper motor.
Fabricated reserve coolant/expansion tank and over-flow tank.
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Craig Roush shows us his custom-built exhaust headers.
LeMans-style front valance from Auto Vintagery in La Jolla, CA.
In 1995 the car was brought back to its original color with a new coat of paint.
MGA 1500 steel wheels on the front, and MGA 1600 steel wheels on the rear.