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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
I bought a 350 block that was claimed to be from an '86 vehicle. I got it for very cheap so I grabbed it up. Now I am trying to figure out everything I can about it to make sure I want to use it.
There is a lot of rust/wear on the block, but I was able to find a few things. I found the "GM 5.7LG SGI" stamp, and I found a number on the front of the block (passenger side), but it is very hard to read (looks like C88506). I also found the (I hope) date code with engine code suffix (V05028AN).
Only problem is, I cannot find anything about these codes. I figure the engine was from Flint, and was cast on May 2nd. I cannot find the suffix "8AN" anywhere though.
Attached is pictures of the block. I tried to get a picture of the "C88506" code I found, but it came out blurry because my camera sucks at up close pictures. I did not get a picture of the date code and engine suffix, though it was in VERY good condition and I am pretty sure it is right (99% sure). I was unable to find the casting number on the block.
That's a "638" block, one-piece rear main seal, roller lifters. Can't see if it's 4-bolt main - was used both ways.
A very common and good block. Used in passenger cars, performance cars, trucks, and crate engines (it's the block I have in the Camaro).
It's '87-later, so if it came out of an '86 vehicle, it was either a very late '86 production, or a replacement engine. "May 2nd" would indicate it's a replacement engine.
Wow, you can tell that just by the "638" on the block? Where exactly is the casting number? I couldnt find it (I am assuming it's imprinted and not stamped like the 638?). Though I didnt know the date code/engine suffix was where it is either, so I'm sure I may have missed it.
Castings are normally referred to by the last 3 digits of their casting number. That's what "638" is.... the last 3 of the casting number of a very common 87-up 350 block, found in all sorts of 350s. On blocks, the last 3 are usually cast into it in a couple of different places, as well as of course the complete number in one place.
The complete number is located here.
Behind the driver's side head, on top of the bell housing flange.
The stampings will tell you a good bit about the engine that the block was originally built into. It may or may not tell you anything AT ALL about the motor that it is now, however. Once a motor has been "rebuilt", most of its resemblance to its original configuration, disappears. However, the stamping will tell you what size motor it was (305, 350, etc.), IF you know the year of it (they re-used stamping codes sometimes after a number of years), which is useful.
Roller block - very good.
Get a picture of the lifter valley for us please? Then we'll know if it's been drilled/tapped for roller lifters. (i'm not sure if this is a one of the ones that may/may-not have been).
Then remove the rest of the plugs from the block, and take it into a machine shop for a hot tank ($40) and a magnaflux ($40). Find out if it's useable. If there's rust on the main cap bearing surfaces then it may need an align hone (extra $150 or so).
But I think it's still a usable block. Have the machine shop measure the bores for you now, to see if it's a virgin bore or not, and find out what size it'll need to be bored out to.
Then you can look at pistons, rings, rods, crank etc etc etc.
All of which, have left no permanent impression in the block, and are therefore irrelevant and useless concerning a block.
Meaning, the stamping codes are marginally worthwhile, occasionally, if you have an engine, and any desire to restore it to its original configuration, or exactly match a vehicle application, or something like that; but, all but useless for a block.
sizes and mains
Those are properties of the block, i.e. the thing he has; and since you can find them out from the casting number, that makes the casting number the only number of value.
Since the cam retainer plate area has been drilled & tapped, the rest probably has been as well. But, should be easy enough to verify.
I'm wondering why those cam bearing webs have been painted. Makes me wonder if it's cracked there. Not a common place for cracks, but suspicious.
The paint marking says "350 L". So, it probably came out of a light truck. Doesn't much matter, as sofa has so thoroughly pointed out (it's a bare block - what used to be in/on it is moot). 2- vs. 4-bolt is about the only detail left to be determined, and that's a matter of looking. And doesn't make much difference, anyway.
This is an old thread but I have questions about my engine. My VIN says its a TBI engine in my 89. I added this question to a few thread hoping somebody knows. There may not be a good answer other than its a 350 roller engine with the wrong heads.
I have a 89 IROC that had a rebuilt engine when I purchased the car. I am searching the numbers to verify what it is. Its a 350 Roller engine with 5.7LG SGI on the back. One the block is it stamped 638 near the plug. On the engine its stamped V0326SAF which I cannot find the SAF listed. 14093638
The VIN shows 350 TBI which I though they didn't make in 89. Funny thing the engine is TPI with TBI heads. 14102193
See post #8 above, about conflating the identification numbers stamped on a block, with being able to tell anything about the engine built out of that block.
You can take the block from a 76 Impala 2-bbl, complete with the stamping that "decodes" to 155 HP or whatever; take off the heads, intake & carb, pull out the cam & pistons, and replace them with racing grade parts; and have a 500 HP engine as the result. Just like you can take the block from a 70½ Z/28 LT-1, and put TBI or terrible smogger heads on it and some peanut cam, and come up with a 180 HP POS engine complete with the romantic-looking block stamping complete with VIN.
Since virtually NO engine that's swapped into a car, above all NOT a "rebuilt" SBC in a situation like you have, will contain the internal and external parts that came in it from the factory in totally unmodified form which turned the block into an engine, looking up the stamping on the block WILL NOT tell you what engine you have.
The block casting number (NOT stamping code) will however tell you what bore size the block is; 3.736", 4.000", 4.125", etc.; and from there you can figure out what the CID is most likely to be. For example it is extremely rare that someone would build anything but a 350 out of a modern 4" bore block, although it's possible that somebody might have put a longer-stroke crank in it and made a 383 engine out of it. Which of course the stamping code wouldn't tell you EITHER. Once you know the bore of the block, you can then look at the piston configuration (flat-top, dome, dish, etc.), the heads, the cam, and so forth, and make an educated guess about what sort of engine you have.
But in a case like yours, the likelihood that the block stamping is going to tell you that the engine came out of a 95 Caprice, green with tan interior and steel wheels with AM/FM/CD radio and automatic climate control, is FANTASY LAND.
You have an engine made out of a 350 block that maybe came from such a car; it happens to have heads on it that COULD HAVE come in such a car also, BUT the left one might have come from a 88 Blazer and the right from a 93 Buick; and the Lord only knows what cam might be in it and what pistons somebody jammed into it. FORGET trying to extract useful information from the stamping code.
You have a 350 block, therefore most likely a 350, and 350 TBI heads. Those heads are GROSSLY inferior to TPI 350 heads and therefore are limiting the power output of the engine to a significant extent. As said, it may run "just fine" as-is, in your opinion (which is all well and good... not saying it doesn't); but you might be REALLY SURPRISED how much better it could run with better heads. And meanwhile, you have NO IDEA what pistons are in it (i.e. what compression it has) or what cam is in it, since there's about 99.999% odds that those aren't original, leaving yet further opportunities for improvement. (again, not saying you "should", or any such; only that there's that much OPPORTUNITY for improvement) It is also about 99.999% certain that you do NOT have the engine that is described by the stamping code on the block.
Thanks for the lookups. I gave up on the ID. Its been rebuilt for sure and who know with what parts. Its a roller engine and basically I have a nice redone car with a decent engine. Its never going to outrun my 2018 2SS but is fun to drive. One day I may pull the engine and change the heads to TPI and at least know the pistons and cam specs.
Thanks for the lookups. I gave up on the ID. Its been rebuilt for sure and who know with what parts. Its a roller engine and basically I have a nice redone car with a decent engine. Its never going to outrun my 2018 2SS but is fun to drive. One day I may pull the engine and change the heads to TPI and at least know the pistons and cam specs.a
Tracking down TPI heads in this day and age would be a exercise in futility. Get a decent set of aftermarket aluminum heads. The power difference between stock TBI and TPI heads will not even be noticeable with the factory cam, TPI and exhaust. While you are in there swap the intake and cam along with a full exhaust from the head ports to the tailpipes.
I had an 8.75:1 compression 1-ton 350 TBI in my 83 G20 van that made more HP and TQ with TBI than many bolt-on 350 TPI engines make. Just a LT4 roller cam, 1.6 roller rockers, edelbrock performer RPM intake, 454 TBI and Doug Thorley Tri-Y headers into a dual 2.5" exhaust with a X-pipe and magnaflows. Made 330 rwtq and 255 rwhp with the stock GM LT4 cam and TBI heads. The rest of the setup is more restrictive than the TBI heads ever thought about being on a mild 350. An Elgin E1136 would have gained another 10-15 hp over that without sacrificing any torque.
02-23-2008, 03:16 PM
