Home | '86 Cutlass | '94 Caprice | Other cars | Technical Info | Events | Links | Services |
'86 OLDSMOBILE Cutlass Supreme - the engine, transmission, and axle work - CLICK THUMBNAILS TO ENLARGE

This shot makes a nice screen saver! It still ran low 13's in 2002 with the street tires and in the 100+ degree Norwalk heat.

The engine is a 455 cubic inch Oldsmobile V8. Some of the basics internal components of the engine are a nodular iron crankshaft, factory connecting rods resized with ARP rod bolts, ARP main studs, Milodon high volume oil pump with a 3/4" pickup tube feeding out of a Moroso 7 quart pan. Dick Miller Racing camshaft oil restrictors are installed, and the main bearing feed holes are enlarged. I used Keith Black #KB-132 hypereutectic pistons (free floating wristpins), yeilding a 9.3:1 actual compression ratio with some block and head milling. The ported "C" code heads with 2.07/1.68" valves, Isky double valve springs, and have the center divider brazed and the heat crossover passages filled with aluminum. The engine is topped off with an Edelbrock Torker intake and a Stage II 800CFM Quadrajet by the Carb Shop. A Walbro GSS307m in-tank electric fuel pump and Mallory return regulator keep the carb fed. I made a set of inside the chassis headers out of Dynomax 1-3/4" big block A-body headers.
Shown to the left is the short block with the M & J Proformance main bearing support straps installed. The M & J straps are .500" thick, and machined from round 4340HT heat treated high strength steel. Starting with round stock gives the steel straps more uniform grain structure. They can be installed with or without shortening of the factory main bearing caps. My caps were milled .500" for their installation. Installing the straps on stock height (they still must be machined for flatness on the top) will make for a stronger installation, but make oil pan fitment tougher, and stud length selection more difficult. The straps help prevent main bearing cap deflection, and will increase engine bearing life. Get ARP main studs and the straps when you have your block prepped. A block line hone will also be needed.

Click to enlarge the picture in a new window.

Pictured are not my heads, but a set of C casting heads prepared the same as mine. In this picture you can see the brazed center divider. Here are the average port flow numbers for cylinders #1,3,5,and 7 on my engine.

SuperFlow SF-600 Flow bench
Cylinder head flow at 28" H2O (CFM) SuperFlow SF-600 Flow bench
"C" casting, 2.07" Int/1.68" Exh, 4.155" bore size

LIFT .100" .200" .300" .400" .500" .600" .650"
INTAKE 50 115 176 213 244 257 266
EXHAUST 52 97 130 152 167 175

I ported these heads back in 2000 without any flow bench development. Flow bench values DO vary from one bench to another. C casting heads in stock form on this same bench flow about 10 - 15% less than my heads. Also, port flow is much more equal than with stock heads, especially on the exhaust side. The intake flow values were within 2-4CFM at higher lifts. I would love to prepare another set of C heads, and change only the heads and see what the track times are.

From the first time the engine was started in the spring of 2002 with the Comp Cams Xtreme energy cam, the valve train was noisy, regardless of how I adjusted the Comp Cams adjustable rocker arms. At the end of the 2002 racing season, the engine developed an extremely loud tick on the #6 intake... here is the #6 Intake lifter - note the broken metering plate - the piece is below the plate with 4 holes in it. This failure is was a result of the lifters not metering oil correctly. With recent upheaval in the lifter industry, many people are having trouble finding quality lifters at a reasonable price. Pre-oil your engine on the stand before you install the intake - if the pushrods do not squirt oil, replace the lifters!

For 2003 I used a Bullet Racing Cams grind with Sherman Racing Lifters. The camshaft is a single pattern cam with 239/239 degrees duration @ .050" lift, .541/.541" lift, and 110 degree of lobe separation. The Sherman Racing lifters are used by Super Stock racers to gain power. They only have .015-.020" of hydraulic take up and modified internal valving, so they retain the hydraulic automatic adjustment of a standard lifter with gains in lift.

At this time there are no commercially available headers that fit an Olds big block in an '78-'88 G-body WITHOUT 2 tubes going outside the frame and limiting steering clearance (like the Hooker 3203's). Here are the headers - I built them from Dynomax '68-'72 A-body 1-3/4" big block headers, and mandrel J-bends. There are 29 welded joints in them, and I replaced one collector. I used a MIG welder with .030" flux cored wire. This was a difficult and time consuming fabrication. The headers are Jet-Hot coated.

CLICK HERE to see the driver's side header during the construcion.

CLICK HERE to see the passenger's side header during the construcion.

CLICK HERE to see another shot of the passenger's side header during the construcion. Notice that between the last picture and this one, the #8 tube was routed differently (to clear the transmission bellhousing)

CLICK HERE for more information on inside the chassis G-body headers.

Interseted in a set of headers like this? Click here to go to the Services page.

I wanted to try a Torker single plane intake for 2003, but I did not like the way the outer 4 runners kink around the intake manifold bolt between the runners. I modified my intake as others have done by having the intake welded, then porting it.

click on the picture of the intake to see it after welding, and before the porting.


The last year for the big block Olds was 1976, and the first year for the R4 radial type air conditioning compressor was somewhere around 1978, so there were never any A/C brackets made to mount the Cutlasses A/C compressor to a 400, 425, or 455 Olds. Shown here are (2) 307 Olds air conditioning brackets - to fit on the 455, they need to be lengthened 1.3" (the difference in deck height between a small block and big block Olds). I used 3/16" hot rolled steel bar from Home Depot and the trusty MIG welder.

To mount the 307 Cultass power steering and alternator, just change out the bracket I am pointing to with one from a 70's big block car. 1976 was the last year for the 455, but I am not sure when the first year for this type of power steering was - I would guess around 1970 to 1973.

Click on the picture for a larger view.

A common problem with the G-bodies is putting true dual exhaust on the car with the stock "single hump" cross member. Shown is not the cross member on my car, but one I modified in the same fashion as mine. I cut clearance for the second head pipe, then welded a piece of .100" thick steel over the hole. Then to add back some structural rigidity, I welded a length of 3/16" thick hot rolled bar stock to the top of the crossmember.

Click on the picture for a larger view.

A remotely mounted oil filter was needed after I reworked the headers to clear the larger 7 qt oil pan. I used a Trans Dapt Performance Products #1022 spin on oil filter bypass adapter (13/16-16 thread), a Perma Cool #1791 remote oil filter mount, Aeroquip #10AN braided hoses, and a Fram HP-4 filter. The filter is mounted behind the right front tire on the bottom of the firewall, tucked up inside the frame. The HP series of filters flow a lot more oil than stock filters. The oil line plumbing has changed since this picture was taken... not shown are the Mocal oil cooler and oil thermostat.

One other tip... examine your spin on oil filter bypass adapter - the 13/16-16 threaded center hole on mine was not machined 90 degrees to the flat sealing surface, making it difficult to seal. I removed the sealing 0-ring and sanded the base at an angle untill the surface was true.

I was getting sick of seeing 260 degree F oil temperatures with the TH400, and 240 degrees with the 2004R, so I decided to install an oil cooler. I felt this was necessary because the oil pressure would drop a full 10psi across the board from 200 degrees to 240 degrees. It would take about 1/2 hour to 45 minutes for the oil to reach 240, and I planned on driving this car across the state to car shows and races. I again used #10AN braided hoses. The oil thermostat lets oil bypass the cooler at oil temps under 180 degrees F so that the oil will stay hot enough to burn off condensation. I purchased a Mocal #MOC-25210 25 row (headered style) oil cooler and Mocal oil thermostat through Racers Parts Wholesale (http://www.racerpartswholesale.com) - $188.89. For engine oil, you want a "headered" style cooler like the one shown here. The oil flows through all 25 rows of the cooler at the same time, rather than like in a typical transmission cooler where all of the oil would have to flow back and forth, back and forth several times. The Mocal and Earl's headered style coolers will have less resistance to flow and less flow loss. The Mocal products are very popular among the European and road racing crowd, particularly with Porche 911 owners (air cooled engines). Earl's makes coolers which appear to be very similar in construction and quality, but unfortunately at the time I was purchasing my parts, there was a nation wide shortage of Earl's coolers. I installed an oil thermostat too after reading about oil coolers. Without an oil thermostat, during highway cruising the oil temperatures could drop too low to burn off contaminants and water condensation. An advantage to the Mocal oil thermostat over the Earl's, B & M, or Perma Cool oil thermostats is that it comes with male -10AN fittings machined into the housing, rather than a female NPT fitting that must have a separate -10AN male nipple screwed into. This eliminates 4 possible places for oil to leak, and also makes for a smoother transition for the oil flow from the lines to the thermostat The Mocal oil thermostat is Racers Parts Wholesale part #MOC10AN ($89.99). You can see the oil thermostat on the passenger side fender well to the left of the A/C compressor in the overhead engine bay picture below.

Here is a better shot of the engine bay. Note the oil cooler lines and thermostat on the left, as well as the large blue Jacob's Ignition external coil. If you follow the braided -10AN hoses to the front of the car, you can see the Mocal oil cooler mounted in front of the A/C condensor. The Mallory return style fuel pressure regulator is mounted directly off of the carb. CLICK HERE to go to the "EFI Pump Info" page in the Technical Information section to see details of the new electric in-tank fuel pump installation.

The rear axle - an 8.5" 10 bolt with 3.73:1 gear ratio and GM clutch type posi. The reproduction W27 rear end cover is from Dick Miller Racing. Also to be noted here are the Bendix drums, Torque Tech mandrel bent dual 2-1/2" exhaust, Dynomax mufflers, and the boxed (welded) upper and lower control arms with Energy Suspension polyurethane bushings.

The new heavily modified TH-2004R transmission and Yank 3000 10" converter. Driving down the highway with the 3.73 gears is a DREAM! With the torque converter lockup clutch engaged, the engine turns 2200 RPMs at 65MPH. The car achieved 14.5 MPG on a recent highway trip. The higher quality high stall torque converters also have better engagement characteristics than cheap converters at low RPM and light throttle.

This the best time slip so far (click to enlarge). This run was with BFG Drag Radials, 235/60/R15. I have found the best launch technique to be to bring the engine up to 1100-1200 RPM, then nail the throttle from there (just off idle).
60' 1.768
330' 5.096
660' 7.927
660'MPH 86.53
1000' 10.324
1320' 12.396
1320'MPH 110.13

This was in pretty good air at Dragway 42 in West Salem, OH on Nov. 23rd, 2003. I removed the mufflers to get that time. The previous best was 12.58 @ 108.6 MPH through the mufflers. This shows that the current Dynomax Super Turbo mufflers are too restrictive for my power level.


MAIN '86 Cutlass PAGE             BODY WORK & PAINT PAGE

* Updated 09/18/03 *