70 Z28 LT-1 350/360
SPECIFICATIONS
Engine Specs 1 Engine Specs 2 Engine Tune up Distributors
1970 LT1 ENGINE
For 70, a new forged-steel crankshaft was used with drop-forged steel connecting rods.
Forged-aluminum 11.0:1 pistons made by TRW. Fitted with a dual snorkle Smog cleaner.
HP-360 @ 6000 rpm and Torque 380 @ 4500 rpm
Cam #3972178
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intake duration of 317 degrees |
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exhaust duration of 346 degrees |
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overlap of 96 degrees |
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Lift - Intake - .4586" (includes lash - .024") |
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Exhaust - .4850" (includes lash - .030") |
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rocker arm ratio of 1.5 to 1)
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Heads
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cast iron |
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2.02 inch diameter intake valves |
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1.60 inch diameter exhaust valves |
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64cc combustion chamber |
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screw-in rocker arm studs with hardened steel pushrod guide plates |
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intake valve 2.02 in. |
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exhaust valve 1.60 in. |
Induction
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cast-aluminum, high-rise, dual plane intake |
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780-cfm 4 barrel carb with1.686 inch diameter primary and secondary throttle bores |
Click on thumbnail for larger photo below
Engine Area
Oil I use with enough ZDDP to protect the flat tappet engine. I do add 1 bottle of GM EOS with the Valvoline oil.
Joe Gibbs Hot Rod oil does not need EOS. If you add anything it will disturb the chemistry.
I started to use ZDDPlus to non synthetic oil to be better on the pocket book.
GM stopped selling AC PF25 and PF35 oil filters which did not have the anti drain back valve.
Napa Gold 1061 is the replacement for the PF35 oil filter and it also does not have the anti drain back valve.
SB and BB Chevy's already has an anti drain back valve in the oil filter spin on adaptor.
My build date is 05E = May 5th week.
Stock Pushrod
Using 1.52 Comp Magnum Roller Tip Rockers, part # 1412-16 after my cam swap
Valve Stem O Ring Oil Seal
Compress spring
Grab keeper locks with magnet
Remove spring
Remove old oil valve seal O ring
Install new O ring on stem, then push in groove with wooden coffee stir stick
What's a CE block?
Underhood insulation was part of the Z87 customer interior option.
Available from Chuck Sharin at http://www.nastyz28.com/forum/index.php
Factory hood insulation clips
Side Cowl Weatherstrip
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Z87 Custom Interior:
Includes Custom Seat, Door and Quarter
Trim; Glove Com-
partment Light and additional Instrument Lighting; Wood-grain Accents on Steering Wheel, Instrument and Door Panels;
Luggage Compartment Mat
and Special Hood and Interior
Insulation. Trim Code must be specified |
Alternator
1100837 - Used also on 350/320 HP/, 396/375 HP/ or 454 Eng.
37A = 37 amps
0D - 0=1970 D=April
Stencil of the 5 hole 1970 bracket - click on pic, print original size, it's on a 4x6 sheet of paper
Regulator
Capacitor is # 1964086 .5 MF
Horn Buzzer
Balancer
7712 balancer is GM # 3947712 and is dated April 1970 ("D0") for my May car.
Balancer Fully Installed
Timing Tab
Crank Pulley
part # 3956668 CG
Water Pump Pulley
part # 3947824BV
Clutch and Fan
70 Z28 clutch part # 3946804 3" from the bottom to top
Examples of Date Codes
A20A
A = Jan
20 = 20th day
A = 1970
C5A
C = Mar
5 = 5th day
A = 1970
Fan Blade
part # 3947772
date code C70 - C= Mar 70 = 1970
Shroud
Temperature Sending Unit
GM orig part # 1993369. Updated part # 12334870
The orig one is stamped AC - MADE IN U.S.A. - 12 VOLT
The new one has nothing stamped.
There are more threads on the new part and the diameter of the
sensor end is .55 compared to .60 on the orig.
Used on 1967 6 & 8 cyl
1969 8 cyl
1970 307 & 350
3972296 Accelerator Cable?
1100 mi LA 70 Z28 showing the accelerator cable
336969 Accelerator cable at interior and engine side
A.I.R. Smog System
My smog system is going back on my car after I clean it up due to the Smog Police being out.
I took these off and left them off in 1985 when the engine was rebuilt. See below.
If I took more care these tubes would have been reusable today.
Rear - 7801149 310 D23
Date code 12001S
120=120th day
0=1970
1=1st shift
S=Saginaw Plant
Diverter valve
2 gaskets are required on the pump, one on the diverter elbow to the body
and the other on the diverter to the elbow.
Check valve 1969-74 part # 5371992
Original tower clamp
Side by side new and old (the curved pipe on the right was only available for 73-74 cars.)
The curved passenger pipe is for sale $150.00 OBO + shipping.
Above are new GM smog tubes.
The passenger side for a 70 Z28 was NLA so I bought 73-74 part # 330508
The drivers side is part # 343763. It has a flat spot for some reason. Not sure who makes them but GM should do a quality check since it's incorrect.
I'm selling the passenger side pipe (above) for $150.00
Repo Smog Tubes from Early Birds Toronto which come from http://www.drclassic.com/catalog/Camaro/Exhaust/Z00052.html
Intake TCS Switch
Smog pump vacuum hose locations
Switch painted with hi heat aluminum paint
stamped part no.
Installed switch
Smog pump pulley - 3932458DA
Diverter Valve
For Sale:
GF Diverter Valve Sticker
1.50 ea or 6 for 8.00 (all US funds)
Shipping/Handling: 1.00 to USA and .57 in Canada.
Diverter Valve Elbow
Upper Bracket
Smog Pump upper mounting Bracket. Mounts to the alternator mounting bolt and the 2 bolt holes on the water pump.
Lower Bracket
Smog Pump lower mounting Bracket. Mounts to the block to the right of the fuel pump.
Smog pump installed with upper
bracket that attaches to the water pump
Smog pump and alternator
Exhaust manifold pipes installed before the black smog tubes. These tubes were about $12.00 each.
So I just bought 1 and cleaned up the old ones and reused them.
Smog System Installed and Completed
Complete Smog Unit
Showing the 4 way vacuum connector.
The front 2 can be reversed, whichever fits best for your curves.
Battery Tray From GM in 1985
Heater Hose Clamp
NA9 Heat Shield
Even though this heat shield was installed on California Z28's, I always had a heat shield under the carb in order to stop fuel from percolating which
causes surging. When the proper shield was available, I bought one and installed it in place of my big block Camaro shield.
Distributor
The distributor is set with stock springs and timed at 19 degrees initial and 37.5 degrees total advance @ 3000 rpm (vacuum disconnected).
My 1970 Numbers for a 4-spd car:
Holley - 780 cfm 3972121 List 4555
Distributor - 1112019
Block - 3970010
Heads - 3927186
Exhaust manifolds - 3942527/3946826
Intake - 3972110
Delcotron - 1100837
Bell Housing - 3899621
4 spd and auto
1112019
0=1970
C=March
18=18th day of March
Dist Vacuum and Cam Info
There is no Part No. that ends in 201 for the MS 201 15 vacuum advance in the GM Camaro Parts Catalogue for the 70 Z28. So I assume this part was assembled with the distributor when new on the dist line then when someone needed a replacement they ordered 1116163 from GM Parts. Therefore both 201 15 and 163 16 are correct for the 70 Z28. I still have my worn 201 15 that I replaced along with the dist cam in '85. So in I purchased part # 1116163.
Note: The 1st 2 digits MS is the original manufacturer for the vacuum unit. The first 3 numbers refer to the last 3 numbers of the Delco part number. The final 2 digits represent the number of crankshaft degrees of advance built into the vacuum unit.
Vacuum Part # 1116163 stamped as MS 163 16
CAM Part # 1967002 Stamped as 530 CCW
My old parts from the orig owner that I replaced were ( I still have them) are MS 201 15 and the CAM was Part # 1967002 stamped 530 CCW
I had a broken spring post so I had to take one off the worn 530 CCW and tack it.
Orig 201 15 Orig 530 CCW New 530 CCW New 163 16 vacuum
Crane XR-i module that replaces the points and condenser
Distributor Removal and Installation
Before you remove the dist, set the motor to TDC on # 1 cyl then with masking tape, mark where
the rotor is pointing on the dist body. Then measure to the right 1-11/16. That should be where
the rotor turns to when you pull it out. When you go to install it, this right side position is
where you need to have the rotor so it engages with the oil pump.
When you install it, the rotor automatically turns to the right and turns to the left when you remove it.
Distributor No Distributor Parts
Other Engine Shots
TCS Temp Send Unit TCS Relay
Starter
680
1108418
0E22 3 - May 22 3rd shift
Hidden Wiper Motor
9901B - Decal decodes as 99th day of 1970 , 1st shift, "B" assembly line
My build date is 05E which decodes as May 5th week.
No wipers seen
Extra Arm on the drivers side for hidden wipers
Trico 18" rubber wiper blade insert with lock tab with 29 loops.
Brake Vacuum Hose
Coil (One wire you can't see is the black points wire to the - side of the coil).
Coil showing the radio suppression condenser
Rad Support Rubber Mounts
Used for both upper and lower locations. Same part #, 2 upper and 2 lower per car.
Small block part # 371189 Big block part # 6264100
Breather
Gas Cap
Tail Pipes
Tailpipes from a 70 Z28 that was 6 Months old.
My tailpipes are like the 71 Z28, that angle inward. It came like this when I bought the car in '81.
I'll be getting the 70 type on soon.
Brake Booster, Metering Block, and Proportioning Valve/Brackets
Original Master Cylinder
Original Master Cylinder 5470409 - 1 1/8 D2 ????
I see no stamped numbers or letters on the machined pad. 2 pics, 1 with a flash and 1 without.
70 Z28 Master Cylinder Cover
Keeping my batteries charged over the winter with a 1.5 amp maintainer. It works like the Battery Tender model, but costs less.
Made by Schumacher
Insulator sleeve on temp cable and + batt cable
Pos (+) battery cable cover
Spark Plug Heat Shields
Original and aftermarket shields. The new ones are from Ground Up.
The only difference is that all 4 shields are bolted to the shield support.
The original support was welded on spark plugs 2-4 and 6-8 locations and
bolted for 1-3 and 5-7 spark plug locations.
If you need new bolts at the engine to mount these, they provide 4.
You can tighten the heat shield brace on #1 & #3 plugs by first installing the brace and then tilt it
up a bit so you can get a box wrench on it to tighten it.
The other 3 can be tightened from under the car after it's jacked up.
Spark Plug Heat Shields - Factory 70 and current from GM which are incorrect.
Exhaust Manifolds Painted With Eastwood Factory Gray Non Rattle Can
Heat Riser Installed Position
Other Reference Material
Setting Solid Lifters Engine Torques Block Casting #s Cylinder Head ID
Spark Plug Diag
Camshaft Specs
