March 18,2002---This all started when I planned to rebuild an '89 350 I pulled from my delapidated Suburban. The plan was to simply refresh the engine using aluminum heads, performance cam and new intake. I did not plan to touch the bottom end. Well when I figure the amount of HP/TQ this freshened 350 would produce and I started looking at other alternatives. I found one for sale in the Sunday newspaper. Everything seemed to fall into place with this engine. I was off the day I called, the engine wasn't far from where I lived, the guy wanted to get rid of it fast and he'd deliver the engine to my driveway. What more could I ask? Below is the donor 454 V8 I plan to rebuild with some serious Hi-po parts. It looks a little rusty because its been out in the elements for a few months. Most of the computer and pollution equipment is still attached to the engine. The owner had planned to sell it to someone who could merely transplant the engine into another vehicle and fire her up. I have a few other plans though. Much to my surprise the block turned out to have 4 bolt mains. The stock 454 put out about 230HP and 385 ftlb of torque. I know I can add a couple horses here and there.
Here's a shot of the intake ports on the aluminum heads(12363391). They're described as oval ports but as you can see they're more rectangular shaped than oval. They should perform much better than older ovals. Intake gasket: 12366985, intake bolts: 12367959, head bolts: 12367779
This head is identical to P/N 12363399, except it has 2.25" stainless steel intake valves, and 1.88" stainless steel exhaust valves with 11/32" stems.This head is used on G.M's 502/502 h.p. crate engine. Large oval port design, 290cc runner volume , Semi Open Combustion Chamber. It also includes high performance valve springs, valve spring caps, keys and valve stem seals.These springs are good for up to .680". Spring pressure closed is 140 lbs. Spring pressure open is 368 lbs.
These heads are designed for high horsepower 396, 427, 454, and 502 engines.
Technical Note: For 502ci engines, use head gasket kit P/N 12363411 and no sealant on the head bolt. For all big-block engines, use intake manifold gasket kit P/N 12366985, with intake bolt kit P/N 12367959, and cylinder head bolt kit P/N 12367779. Casting number for this cylinder head is 12363391.
April 2002---These are the heads I'll be using. GMPP aluminum oval intake ports, 110cc chambers, 2.25 intake valves. Number 12363390. This was the best flowing head in it's class(290cc) as tested by Hi-performance Chevy Magazine. Combined with the TRW pistons this should give me a CR of 9.4:1
January 2005- with a little research on Chevytalk.com I cam accross this information on the heads and springs. I asked about:
1. Max spring lift.
2. Retainer to valve seat clearance.
3. seat pressure
Maximum Spring Lift: 140 lbs at an installed height of 1.940. Binds at 1.20
this gives you .740 of spring to play with. They list for use ( as assembled from GMMP ) .680 max lift. Way more than any street /strip cam !
They are rated at 368 lbs per inch. They are a true dual spring set up, not an outer with a flat inner dampner.
These heads were set up to use a mild roller cam, thats the reason for the strong spring.
On the cam I used (XE284) Comp cams list two springs. A base spring and an upgraded spring. This spring that comes on the heads is just a little stronger than the optional spring. I have not had any problem with my cam/ lifters on these heads/springs.
.300"... 193 ... 145
.400"... 233 ... 168
.500"... 272 ... 189
.600"... 299 ... 202
.700"... 318 ... 210
.800"... 327 ... 230
April 15, 2002. Here's the intake and carb combination I'll be using. The intake is a Weiand 8019 Stealth for oval port BB's. It's listed a single plane intake but I think it's more of a combination of bioth a single and dual plane manifold.
The carb is a Holley 830cfm double Pumper. No choke with mechanical secondaries. I plan on removing the choke tower too!
Camshaft Specification Table
Part Number 11-678-5
Engine 1965-1996 Chevrolet 396ci-454ci 8cyl.
Grind Number CB XS282S-10
Valve Adjustment 0.016 0.016
Gross Valve Lift 0.59 0.598
Duration At 0.015 Tappet Lift 282 290
Duration @ 0.050 244/252
Valve Timing At 0.015
Intake 35 67
Exhaust 79 31
These Specs Are For The Cam Installed At 106 Intake CL
Duration At 0.05 244 252
Lobe Lift 0.347 0.352
Lobe Separation 110
Recommended Valve Springs 924-16
July 2002, here's the block shortly after coming from the machine shop. It cleaned up quite well. It was hot-tanked,stripped and had new Clevite cam bearings installed.
The cylinders were bored 0.060, so now this 454 is actually a 468! If you look closely, you can see a little of the cross-hatch honing inside the cylinder walls. I painted the block, first with POR-15 Chevy Orange and then with a top coat of 500deg+ Chevy Orange. I left the brass freeze plugs natural.
Size Does Matter!
The cross-hatch honing is clearly visible in this shot. I coated the lifter valley and timing chain area with Gyptal red. The coloring is a little off though....it's actually more brown than red. The Glyptal should reduce friction in the valley and aid in oil return. Pushrods are Manley 4130 CHROME MOLY 3/8 PUSHRODS .080 WALL Meticulously formed ends with exact radii Excellent concentricity, closely controlled length Heat Treated and Black Oxide Finish. Max engine speed 7500rpm. Max open spring pressure: 400lb
In 1970 only 4,473 454 Corvette's were produced of a production run of 17,316. Only 25 of those 4,473 came off the assembly line with the "rock-crusher" M-22 Muncie transmission.
The General referred to the big-block engines built between 1965 and 1990 as the Mark IV (Four) family of engines. They were replaced in 1991 by the new generation of big-blocks titled Mark Five or GEN V.
The earlier Mark IV engine blocks were offered in two- or four-bolt main caps, while the GEN V all have four-bolt mains. Interchangeability of the front four-main caps is possible if they’re align-bored, but the rear cap will not interchange because the GEN V uses a one-piece rear-main seal instead of the two-piece used in the Mark IV.
This procedure and specifications are for stock stamped rockers. If you have non-stock rocker ratio you will need to adjust the setting to account for the different ratio. The procedure is still the same but the spec will be different.
For the LT-1 The factory specification is .024"/.030", but you should set them at .016"/023" cold with the engine not running to compensate for the fact that the rocker ratio at the top of the ramp is closer to 1.37 rather than 1.5.
Also, you should use the procedure developed for the 30/30 cam because the exhaust cam is on the ramp at TDC and the inlet is barely off.
The following text is the procedure:
"30-30" SOLID LIFTER CAM VALVE ADJUSTMENT
By John Hinckley and Duke Williams
The traditional method of adjusting valves one or more cylinders at a time with each cylinder at TDC is fine for hydraulics and for most solid-lifter cams, but NOT for the factory "30-30" solid-lifter cam used in '64-'66 L-76 327/365 Corvette engines (and in '67-'69 Camaro 302/290 Z/28 engines); this cam has VERY long clearance ramps that are .020" high, and at TDC for any cylinder, both the intake and exhaust valve for that cylinder are still on their ramps, NOT on the cam's base circle, which is why the Service Manual for all cars so equipped says specifically to set them "hot and running".
There is, however, a better way to adjust the valves with a "30-30" - you can set them "cold and not running" by setting the intakes at 90 degrees ATDC and the exhausts at 90 degrees BTDC - so the lifters are on the base circle, not on the ramps. This has been confirmed with cam lift/crank-angle diagrams, and I've done mine this way - results in a nice mechanical "singing" sound, no "clacking", it runs better, sounds better, idle is more stable, and throttle response is improved. Several other Z/28 owners have followed this procedure as well since we developed it, and all of them have seen the same positive results.
Set them cold at .026"/.026". The actual measured (stamped rocker arm) ratio at the lash points is actually about 1.37:1 (not the design 1.5:1, which is a max lift measurement), so the clearance ramp, which is exactly .020" high on the lobe, is all taken up at .0274" clearance; .030" clearance with the valve closed is too loose - the ramp ends/begins before the .030"clearance is taken up, resulting in the valve being lifted off and returned to the seat at greater than ramp velocity. This will contribute to valve seat recession, and can cause valve bounce at the seats at high revs - it will also be noisy.
You can adjust two valves at each 90-degree rotation point, starting at #1 TDC, turning the crank 90 degrees at a time seven times (measure and mark your balancer first at 90-degree intervals from TDC). Removing the plugs simplifies rotating the crank, but you were going to change them anyway, right? Proceed as follows:
TDC #1 - 8E, 2I
90 deg. - 4E, 1I
180 deg. - 3E, 8I
270 deg. - 6E, 4I
0 - 5E, 3I
90 deg. - 7E, 6I
180 deg. - 2E, 5I
270 deg. - 1E, 7I
Start at TDC #1, then rotate 90 degrees at a time, setting at .026" cold. If you like, you can then go back after you're done to each cylinder's TDC position and check clearance on that cylinder's two valves, and you'll find that they've closed up to .024", indicating that both valves are still on the ramps at TDC, as I pointed out in the beginning.
Chevy Production Big Blocks
The Chevy big block was introduced in 1965 with a 396 cid Mark IV engine developed from the 1963 Datona mystery engine. The engine was basically developed as an answer to the highly successful GTO with its 389 cid engine introduced in 1964. The 396 was first offered in the Chevelle at 375 HP, in the full size Chevy as 325 and 425 HP versions and in the Corvette with up to 425 HP. In 1966 the 396 was bored out to 4.250" producing a 427 cid engine. The 427 was offered in the 1967 Impala SS rated at 385 HP and in the Corvette it was first offered in 1966 and was uprated with 3-2 bbl carburetors to 435 HP for 1967.
In 1967 the L88 427 was also provided in approximately 20 Corvettes with an advertised HP of 430 but actually producing in excess of 550 HP. The L88 required minimum 95 octane gas to avoid possible damage to the engine and was meant to be strictly for racing. 1970 saw introduction of a stroked 427 resulting in a 454 cid engine. The 454 was offered in the 1970 Impala, Chevelle SS, El Camino SS and Monte Carlo SS in a 360 HP version and in the Chevelle and El Camino SS in a 450 HP version. The 1970 Corvette LS-6 was offered with the 390 HP 454 cid engine. 1970 also ushered in the 402 cid engine which was also known as the 396 in some Chevys and the big block 400 in others. In the 1970 Camaro SS, Chevelle SS and Nova SS the 402 cid engine with 375 HP was known as the 396 and the cars carried the 396 badge. From 1970 to 1972 the 402, 454, 465 and 495 cid engines were introduced.
The short big block V8 has a deck height (centerline of crankshaft to cylinder deck measured along the centerline of the bore) of 9.80" and a height (centerline of crankshaft to top of engine along the center of the V) of 10.75". Cylinders are spaced on 4.84" centers on each bank and the centers of cylinders on the two banks are offset to accommodate the two connecting rods on each crank journal. The big blocks have been produced in 3.935", 4.096", 4.125", 4.250", and 4.440" bores and strokes of 3.47", 3.76", and 4.00". Over the years from 1965 to 1995 the big blocks were offered in nine different displacements from 366 cid to 502 cid.
Below is a table of the main dimensions for all production big block Chev engines from 1965 to 1995.
Production Big Block V8’s
CID Years Bore Stroke Block Material Actual Liters Main
396 65-69 4.096 3.76 Cast Iron 396.4 6.50 2&4 bolt
366T 66-95 3.935 3.76 Cast Iron 365.8 5.99 2&4 bolt
427 66-69 4.250 3.76 Cast Iron 426.7 6.99 2&4 bolt
427T 69-95 4.250 3.76 Cast Iron 426.7 6.99 4 bolt
427 69 4.250 3.76 Alum.w/liners 426.7 6.99 4 bolt
430 69 4.440 3.47 Alum.w/liners 429.8 7.04 4 bolt
454 70-91 4.250 4.00 Cast Iron 454.0 7.44 2&4 bolt
402 70-72 4.125 3.76 Cast Iron 402.0 6.59 2&4 bolt
465 70-71 4.440 3.76 Alum.w/liners 465.7 7.63 4 bolt
495 70-71 4.440 4.00 Alum.w/liners 495.5 8.12 4 bolt
495 72 4.440 4.00 Alum.no liners 495.5 8.12 4 bolt
502 92-94 4.466 4.00 Cast Iron 501.3 8.21 4 bolt
All big blocks have 2.75" main bearings and 2.20" rod bearings and all production big blocks used a 6.135" rod length. T is Tall (or long) block with a deck height of 10.20" and vertical height of 10.75".
Firing order 1-8-4-3-6-5-7-2
The other Chevy V8’s
How could you forget the legendary 409 cid engine first introduced in 1962. It evolved from another great engine the 348 cid V8 that ruled the road from 1958 to 1962. The 1961 Chevy had a 348 with the tri-power option putting out advertised 330 HP and with a 4.56 rear end it was unbeatable up to about 90 mph. The 348 was bored and stroked until it displaced 409 cubic inches. The 409 engine was pure muscle; full sized Chevys turned 12.55 quarter miles at 116 mph. The cam, valves, compression ratio of 10.2:1, head design and large dual exhausts all worked together to produce one of the most exciting engines in history. It was available in the Impala, but hot rodders in the know preferred their 409 in the lighter Bel Air body. The 409 was a great engine but Chevy needed something to answer the Chrysler 426 Max Wedge, the Ford 427 and the Pontiac Super Duty 421. In 1963 the 409 was stroked to 3.65" to produce 427 cid and along with liberal use of aluminum, special heads and intake manifold the Z11 engine/Impala was born. Officially rated at 430 HP, several sources suggest that actual output was significantly higher than 500 HP.
In January 1963, the GM brass passed down an edict to its divisions to stop any work going on with performance programs. Sadly, as a result, only 57 Z11’s were made. They were all T-10 four speed equipped Impala SS cars. However, the Z-11’s that made it to the racetrack cleaned up shop. The Strickler/Jenkins car won the eliminator bracket at the 1963 NHRA U.S. Nationals in Indianapolis, running a 12.10 second pass at a flying 120.16 mph.
Below is a table of the main dimensions for the "W" engines produced from 1958 to 1965.
"W" Family V8 Motors
CID Years Bore Stroke Block Material Actual Liters Main
348 58-65 4.125 3.25 Cast Iron 347.5 5.69 4 bolt
409 62-65 4.312 3.50 Cast Iron 408.9 6.70 4 bolt
427 63 4.312 3.65 Aluminum 426.4 6.99 4 bolt
348 had 6.135" rod
409 had 6.000" rod
427 had 6.135" rod Z-11
ALL "W" family motors used 2.50" main bearings and 2.20" rod bearings
Chevy made big-block crankshafts in two different strokes. The 396, 402, and the 427 all use a stroke of 3.76 inches. These are internally balanced crankshafts. The 454 uses a 4-inch stroke and is externally balanced. All the main-bearing journal diameters for the Mark IV big-blocks are 2.7482 to 2.7492 inches, with the rear main-journal diameter at 2.7478 to 2.7488 inches. The rod bearing’s journal diameters measure 2.1988 to 2.1998 inches, making the crankshafts interchangeable.
There are two different types of big-block crankshafts—cast or forged. You can tell the difference by the parting line on the crankshaft throws. The cast crankshafts will have a thin parting line where the two halves were joined to make the complete crankshaft, while the forged crankshaft will have a wider parting line. The 427 Corvette crankshafts are all forged steel.
Here's a set of Hooker super competition Headers I purchased used. There's a little surface spotting visible but I plan to treat the headers with POR-20 which can sustain 1400 degree heat. The headers came complete with a Walker 2.5 ID chambered exhaust system. I couldn't pass on these, the price was great thanks to Marks69BB.
Above & below are stock big block exhaust manifolds appropriate for a 1970 454 without air holes. Casting numbers: 3880828 & 3968869. These are the highest flowing of all the stock big block exhaust manifolds. There is an area in each outlet which can be ground further for even better flow. I'm not sure if I'll use these, but would be ideal for the '69 factory side exhaust system.
Moroso Street & Strip pan:
Kicked-out sump design for increased oil capacity. 8'' deep for maximum ground clearance. Trap door baffle keeps oil in the pickup area. Built-in scraper quickly removes oil from rotating assembly and a uni-directional windage tray screen helps it drain into pan. Accepts up to 4.250'' stroke w/steel rods and 4.090'' w/aluminum rods.
Although I used a Melling's M-77 oil pump, the recommended oil pumps are - Stock oil pumps or Moroso BBC race pump P/N 22150 (Std.. volume race), 22160 (High volume race), 22162 (Blueprinted high volume) - Pickup P/N 24440
This oil pan will fit all BB-Chevy wet sump engines (except Gen V and Gen VI) in most chassis except 62-67 Chevy II, V8 Vega/Monza, Chevelle w/ steering linkage behind crossmember & 55-57 Chevy
TRW-L2399F60 Piston Specifications:
* Bore: 4.310 in.
* Stroke: 4.00 in.
* Rod length: 6.135 in.
* Compression ratio: 9.63:1 (109.4cc heads)
* Head type: .095 in. Dome
* Oversize: .060 in.
* Ring size: 5/64 in. top/second ring, 3/16 in. oil control ring
* Weight: 693 grams
* Dome volume 13.8cc
* For 454 (LS6) with open chamber heads
This is a Carter Street & Strip M6901 fuel pump which should provide 6 psi of pressure. It features a tough, lightweight aluminum housing, silver cast finish, large full-flow valves, and a heat treated lever, 1/4'' NPT inlet and outlet and anti-float springs for high RPM use. I needed to rotate the inlet/outlet to accomidate frame interference on my '70 Corvette.
M-22 (Rockcrusher) Rebuilt some years ago and NEVER used. Coarse input and small output. It has a new rollerized 1st gear and new GM HD synchro assemblies (NOT just brass). ALL gears look good (NOT just the constant mesh gears the speed gears look nice also). Every threaded hole has a heli-coil and all bolts have been safety wired. This trans is 100% GM (NO Autogear- offshore Italian JUNK !!). The numbers stamped into the case are as follows P2K05C / 37439 / CT4, it has a 661 case and a 584 tail housing. This was an "over the counter" trans so there is no vin number on it.
Any quality 80/90 gear oil from a local parts store is more than up to the task of lubrication. It's not necessary to use GM gear additive or lube.
Only 25, 1970 Corvette came off the assembly line with the "rock-crusher".
Bigger IS Better!
July 2003. There's nothing that screams BB than those huge orange valve covers. I finished most of the engine assembly this month. Head bolts are GMPP, head gaskets are the L-88 type from GMPP too. Chrome Moly rings, Manley push rods and stock-type Severe-Duty rocker arms from Competition Products. Piloshed crank, CC XE cam, HD True double roller timing gear all installed. Balancer on. Now need to adjust valve lash (0.022) and add intake & carb. What started out as a budget rebuild quickly escalated into a Balanced, Blue-printed quality rebuild. It's taking much longer but I think I'll feel the extra effort & patience.
I found these cool engine stands at Jeg's. They attach to the engine mounts and allow full access to both the front and rear of the engine. I had intended to use a Lakewood Scattershield but decided to utilize a stock '621 bellhousing and Centerforce dual Friction clutch instead. Clutch alignment should be easier too. The wheels on this stand allows for easy movement around the garage.
October 2002---And now for the L-88 fans. Add some free HP with the addition of the L-88 hood and functional air chamber
September 10, 2001. Here's a pic of the underside of the L-88 hood. The air cleaner assembly is behind a metal screen which can be seen above. The air filter is cleaned by removing the metal screen. I'm thinking of adapting a K&N foam filter to the chamber.
September 10, 2001. This is the L-88 air cleaner assembly. The carb is exposed except for the wire cage. To bring the Holley up to the level of the air chamber, I used a Holley Street Dominator intake and a 1 inch TD step spacer. This with the Holley carb raised the carb the required 3 inches to reach the chamber.
September 10, 2001.***** This picture will give you an idea of how high the carberator sits above the fenders. There's no way a stock hood would fit now!
The 1969 ZL-1 Corvettes
Only 2 of these Corvettes were built with the ZL1 engine and sold to the public (a total of 69 Camaros also received this engine). One was a Daytona Yellow car with side-pipes and the other was a Can-Am White t-top coupe with (what are now known as) black "ZL1" stripes. Adding the ZL1 option added over $4,700 to the price of the vehicle because a host of other options were required (or automatically included). Technically, the ZL1 was a $3,010 option that consisted of an assortment of aluminum cylinder block and heads on top of the $1,032.15 L88 race option.
Unlike popular belief, the engine option was actually widely available via any dealer, the only reason only 2 were delivered was the high price of the option in comparison to the similar (on paper) L88 option. The added cost simply discouraged sales. The ZL1 motor was developed by Chevrolet with the intended purpose of racing. Therefore it was necessary for Chevrolet to produce it as a regular production motor to qualify it. But it is likely that without the efforts of Zora Duntov the engine would never have made it to production. Chevrolet produced the ZL1 motor as a RPO (Regular Production Order) option in 1969 only, and only available as a RPO option on the Corvette. Additionally there were 1969 ZL1 Camaros produced; but only as COPO (Central office Production Order) orders.
The ZL1 engine was as exotic of an engine that could have ever been developed given the parameters Chevrolet had to work with 30 plus years ago. The all aluminum 427 ZL1 was patterned after the cast iron 427 L88, but it wasn't merely just a change of the block casting material. The ZL-1 featured thicker walls and main webbing, along with dry sump lubricating provisions. The bottom end was four-bolt, with a forged steel crank and rods with 7/16 inch bolts, Spiralock washers and full floating pins. Pistons were even higher domed than the L88s, yielding a compression ratio of 12.5:1. Cylinder heads were also aluminum and featured open combustion chambers and round exhaust ports and 2.19 inch/1.88 inch valves, a configuration adopted by the L88 in mid-1969. The aluminum dual plane intake was topped by a 850 cfm Holley four-barrel (double pumper) carburetor featuring mechanical secondaries. The ZL1's solid lifter camshaft was radical (higher lift and different duration), so the engine could live in the upper revs.
Any 69 ZL1 is easily capable of 11s with any competent driver, and running on drag slicks, can easily run deep into the 10s. The quickest documented ZL-1 was a 10.89 @ 130 by Motor Trend in 1968. Some people thought it was 10.60 @ 132 documented by Motor Trend in Oct 69, but that was actually the same car with a prototype LT2 454 motor. (additional details of this can be found in "Classic Corvette, The First 30 Years" by Mike Mueller, Pages 313 - 319, 2003 edition, published by Crestline - MBI Publishing Co.) Zora Arkas Duntoff himself claimed 10.5 on slicks. As we talk about tires, please remember, this is 1969 technology. Slicks of that era were not as sticky as some of today's radials that we find on some sports cars. On top of this, the ZL1's top speed with stock gearing was close to 200 mph, and it could easily go beyond if the gearing was changed. According to a statement by Gib Hufstater (a Chevrolet developmental engineer) in a 1999 interview, "Tom (Langdon) built the engine, I built the car. He got about 710 horsepower out of it."
The white ZL-1 belongs to the Kevin Suydam Collection in Washington state. It is now restored to original showroom condition. Along with its ZL1 option are the J50 power brakes, J56 heavy Duty Brakes, F41 suspension, K66 Transistor Ignition, G81 Posi Rear Axle, M22 Muncie Four Speed, F70x15 Red Stripe tires, A01 Tinted Glass and Front Louver Trim. It has been Bloomington Gold certified and featured in many magazines and numerous books through the years including magazines such as Motor Trend, Corvette Fever, Vette Vues, Classic Auto Restorer, Corvette Quarterly, Vette, Musclecars, and hard back books such as Automobile Quarterly, Corvette-The Complete Illustrated History, Corvette-Americas Sports Car, and American Muscle to name a few.
The yellow ZL-1 is in the hands of a Corvette collector by the name of Roger Judski of Roger's Corvette Centre in Orlando, Florida. He purchased the car in 1991 for $300,000 at a federal government auction. It had been restored in the 80s in Houston, Texas and then sold to a private party. The auctioning of the car was a result of a seizure from Richard Joseph Lynn who was convicted of dealing cocaine and sentenced to life in prison with no parole. Judski’s plan is to keep the car for life and he doesn't drive it.
There is some speculation as to a third ZL-1 in the hands of a private owner but this has not been confirmed to our knowledge. In 1968, Chevrolet brought two ZL1's to the dragstrip for testing -- one red and one white. The Red ZL1, deemed the "Saturday Night Special" was equipped with an automatic transmission available from the L-88 and 4.88:1 rear end gears. Running 9" drag slicks, this car ran 10.89 @ 130 mph! And this run was driven by an automotive magazine editor, not a fully experienced race car driver. This same red car had the LT2 454 motor in it for the Oct 69 Motor Trend tests. Where has it been since? Has it been destroyed?
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