Can anyone tell me what this engine is? I bought a 1985 Z28. The owner says it is a 350, but does not know where the engine came from. Obviously not the original. I can post more pics if needed. Thanks

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What is there to look for to distinguish the 5.0 liter from the 5.7 ?

 

upload pic to your profile and then add too insert image. so we can see.

 

Its got centerbolt valve covers so its a 87 or later roller cam motor. Use a mirror and look at the back of the drivers side head area. There is a casting mark on the engine block that will say "5.0" or "5.7". Otherwise they are externally identical.

 

Thanks subroc. Is there any way to know the year? Will there be any issue in buying parts? I basically want to do a basic tune-up for now to see what it runs like. Should I just pull a spark plug and use that part number to buy new ones? I assume wires will be the same since the layout is so similar.

 

count the number of injectors possibly? 9 and its 87-88. 8 and its newer.

 

There are dates cast on the block but its not really necessary. For the most part a small block chevy is a small block chevy. As for tune up items...your going to want new wires, plugs, cap and rotor. There are two types of distributors that were used on third gens...large HEI...and the small cap version that came later. The large one can be identified by the Coil that is built into the cap where the small one has the coil mounted to the side. Its hard for me to tell in your pictures but it appears you still have the distributor from your car (aka the earlier Large cap HEI). There is a MSD cap and rotor for that one. Its a bit more expensive than the normal replacement but a bit better quality. For wires i see you have headers. If you run wires up over the valve covers you run the risk of burning the wires on the headers. I have mine routed under and up the back of the heads inside of heat resistant wrap. You can get a set of taylor or the like make your own length with 90 degree boots. Plugs you can run what you want. I run NGKs. I forget the heat range off the top of my head.

 

Just because its centerbolt does not mean its a roller cam, if it came from a truck, say a L05, it could have a wimpy flat tappet cam and pathetic swirl port heads. If its from a car however it will be a roller

 

True...i just assumed someone swapped the whole motor in without going through the trouble of swapping intakes.

 

Subroc,

Thanks for the info! The recommendation about the wires make a lot of sense and I'll follow that route.

 

That motor would be from an 87 iroc since it has center bolt valve covers. 86 tpi motors had perimeter bolt valve covers and they were all 305's. 88 tpi motors had serpentine accessory belt drive with ac compressor on the pass. side and alt. on driver side. That motor has v-belt for the ac compressor and its on the driver side with alt. on pass. side. I'm pretty sure that 87 was the only year for this set-up with center bolt valve covers.

 

Jermdm,

More good info!

Thanks.

 

Your welcome. The motor could still be a 350. 87 was the first year for the 350 tpi. Like what subroc said, you have to look on the block and see if its says 5.0 or 5.7.

 

The motor could be any year because the heads could just as easily have been installed on an older engine.

Casting number off the back can at least let you know if it's a 305 or 350 block. Get the stamped numbers off the pad in front of the passenger side head looking down behind the alternator. That can tell you a lot more about what the block itself came from and the year.