Need help identifying 350 block please

[RPMS]

Good Morning, Gentlemen!

 

I finally got some centerbolt valve covers, so I can unveil my mystery long block and try to discover exactly what I've got. I looked up the numbers on Mortec's site, but all they could tell me was that it was a 350, originally built between 1987 and 1995.

 

There are a lot of pictures in this post, so I apologize in advance if you've got a slow internet connection.

 

First off, here is what is cast into the left side of the block above the flywheel:

 

This is on the right side of the block above the flywheel:

 

This is cast into the left head:

 

This is cast into the side of the left head, and in this picture, you can see that the plugs insert perpendicularly to the block:

 

In this picture, you can see that there is a small "1" stamped into the block in front of the #1 plug hole. You can also see that the exhaust ports are pretty darned small.

 

This number is stamped into the block on the front, just to the right of the timing chain, underneath a big water passage. I assume that castings are done at the factory, and stampings are done at the rebuild shop?

 

This last number is cast about halfway down the left hand side of the block, right in the middle.

 

I hope this doesn't crap out the board because of too many images. If anyone can help me assess the performance potential of this block, I'd be appreciative. Right now, my plans are to use this engine to set up the car and get everything running right, then I'll build up a more powerful engine in a year or so to replace it.

 

Thanks!

 

[ October 31, 2001: Message edited by: RPMS ]

[Guest Anonymous]

It appears to have been born June 30, 1989.

From the looks of the overheat indicator washer on the head, the motor is a fresh rebuild.

You mention the "performance potential of the block". What more do you know about the block? Is is a four bolt? It probably is hydraulic roller capable at this time.(?)

What are the actual measurements of the intake ports? Have you chosen an intake yet?

Both the block and the heads are the lighter weight castings, as compared to the older 70's blocks.

Maybe someone knows more about total HP capacity differences between the old and the new blocks?

I doubt that you will ever have to worry about either one, considering the comparatively light weight of Z cars as a whole.

[RPMS]

Thanks for the information, Idaho. I haven't measured the ports yet, but I will if you think that will help identify things. It's a two bolt block, incidentally.

 

I looked through the holes in the intake valley, and I couldn't see anything that looked different from regular hydraulic lifters. Is the difference between a flat and roller lifter blatantly obvious when looking at them this way?

 

Regarding intakes - For this engine, I was planning on using the stock aluminum intake and Q-jet from a 1984 Camaro. Do you see any problems using this setup? I've heard that I might have to hog out the center boltholes in a pre-1986 manifold to get it the bolts aligned properly.

 

I guess it would be pointless to guess at what sort of horsepower this engine might produce, since the dress is completely different than stock. No fuel injection, minimal emissions controls, no catalytic converter, etc. I should probably just throw the thing in there and see what my G-Tech says about RWHP!

 

Anyway, thanks for the info. If you have anything else that you think might be helpful, I'm eager to hear it!

[Guest Anonymous]

Scott,

If you had roller lifters there would be a spring plate which bolts to raised perches in the center of the valley casting. Additionally you would have lifter locking/alignment connectors between each pair of lifters. It doesn't sound like you have these.

Can you see into the cylinders well enough to determine the piston configuration?

What do you know about the camshaft as equipped?

These things will point the way to what manifold would be best. I sounds to me like you should stay with a dual plane manifold with ports which are not larger than your head ports. If you get to much larger you may experience turbulence and reversion in the intake which will cut total performance down.

Your choice of distributer and advance curve will probably make as much a difference in performance as any bolt on part you are considering.

[RPMS]

The build sheet that came along with the engine listed the following information:

 

Rebuild date 4/1/01

Piston: Badger PS67, .04 over

Rings: Hastings E251X

Con Rods: Production

Crankshaft: Production

Main Bearings: King MS-909 20

Rod Bearings: King CR-663 20

Cam: Clevite 274

 

I don't think it's anything more than a standard economy rebuild, especially considering the Badger pistons. I'm not sure what the 274 after the Clevite cam refers to, though. Duration?

 

While this engine is still out of the car, it would be a perfect time to stab a new cam in there should I choose to do so. If I could get a bit more performance for around a hundred bucks, is there a cam with a mild performance grind I should consider?

 

Thanks for all your help! Although I've been turning wrenches for twenty years, this car is my first experience with pushrod V8 engines, and I'm a bit clueless.

[Guest Anonymous]

The 274 most likely refers to a specific model number, but can also refer to advertised duration. (For example a Comp Cam model #260H has an advertised duration of, suprise, 260 degrees) Being unfamiliar with Clevite Cams, and not having a catalog with Clevite products in it though, I couldn't say for sure. However, if we were to assume that it refers to advertised duration, we could compare it to a couple of similar Comp Cams (which I happen to have info on right in front of me) Comp Cam doesn't have a cam with 274 degrees advertised duration, but a Comp Cam 270H has an advertised duration of 270, and an actual duration (@ 0.050") of 224 degrees. A 280H has an advertised duration of 280, and an actual duration (@ 0.050") of 230 degree. If we take the average of the two comp cams and we come up with an advertised duration of 275 and an actual duration of 227 degrees. If the 274 of you clevite cam does refer to advertised duration, then you can expect the acutal duration to be just smaller than the average of our two comp cams. Confused yet? =) I think I confused myself on that one. =)

 

Until I moved to OK a few months back, I worked in a machine shop in CA. I worked on Cylinder heads. Nothing technical though, I was just the helper, magnaflux, pressure test, assembly, disassembly, that sort of thing. Give me a few days on those casting numbers though. I'll run them by my buddies at the shop and see if i can get you some more info, at the very least I should be able to tell you what chamber size those heads are. (Necessary for determining compression ratio.)

 

( Edited four times!!! Ever have one of those days where you can't say what you mean to on the first try? or second... or third...)

 

[ November 02, 2001: Message edited by: aravahan ]

[RPMS]

Man, that would be great! Let me know if you can find anything out. I hate dealing with a mystery motor, but this one was so cheap that I just about couldn't go wrong.

[Guest Anonymous]

i didn't read any of the other posts so i appolgize if i repeat any thing. it's 100% a 350, it's stamped 5.7l on it. other ways to tell ar the bore size, would be about 4 inches, unless it's a 327 they where also 4 inches, 305, 307's junk motors! measure about 3 3/4 inches, unless ur luckey enough to have found a 302 chevy. but they mad those in the 60's. i belive ur motor is from 86-94 actually. i say this becasue my block is the same. just fyi also if u find a 307 just take the crank!! it's the same as a 327 i believe. it will make a great cranking motor!

[RPMS]

Thanks for the info, Ratfink. (man, it sounds odd, addressing a friend that way!)

 

If I found a 327 crank, I'd definitely grab it for my de-stroked 400 project. Weren't they all forged cranks?

[pparaska]

Scott, all the small journal (62-67) 327 cranks were forged. Tough piece. The 68-69 327 Large journal (same as the 350 journal sizes) were both cast and forged, as I recall. The 307 crank is usually if not always cast. So ya got to be careful.

 

Someone used to make bearing spacers to put the small journal crank in the 350 block. To put it in the 400 block, you'd need an even bigger spacer. Grumpy Jenkins used to use bearing shells align honed to the small journal bearing bore size with small journal bearings installed.

 

If that shop in Ventura CA still offers that 327/400 combo 353 kit, maybe they have something. Going with the Ford con rods too?

[Guest Anonymous]

Well, my buddy wasn't as much help as I had hoped. All I got for you was that both your block and heads were 350s used between 80-95.

 

I will take a guess and say since you've got a two bolt, appaently non-hyhdraulic block, your heads are the standard 72cc combustion chamber. With dish top pistons and a standard stroke this should put you somewhere in the low eights, compression wise. Raise this with flat top pistons, or have the heads resurfaced and the deck shaved, but beware, there's only so much you can take off... Take a look on the heads, at the intake manifold bolt holes, are the center two at a different angle than the outer two? if its hard to tell, thread a bolt (3/8 course, I think) in one outside and one inside a few threads in. If they're at different angles you'll need to modify your ' 84 camaro intake manifold to accomidate, but I'd recomend stepping up to a decent aftermarket unit, a good edelbrock or weiand alluminum manifold starts at about $100 and will most likely show a signifigant power gain over the camaro unit.

 

Horsepower is a tricky thing to guage, especially trying to guess at the potential of a motor not even built yet. Your motor, in its stock form, will most likely rest somewhere in the mid 200s, however, it has the POTENTIAL to reach the 4 or 500s. It all depends, as a lot of things do these days, on how much money you want to spend. But while your trying to guess at it's potential, beware of "stacking" horsepower. This is when you buy a set of headers, advertised to give you, say, a 20hp gain, next you add a low restrictive exhaust syetem, advertisesd at a 15hp gain, then you add and intake advertised to give you a 10hp gain. 45hp gain, right? Wrong. These are overall improvements, and the advertised hp gains assume you are adding these things alone, to an otherwise stock vehicle, but if you've allready improved your motors breathing by adding in intake, then adding headers WILL improve breathing further, but not at the level adding heads alone would have. Get it? Stock motor with headers, 20 hp gain, stock motor with intake 10hp gain, stock motor with both, maiybe 25hp gain...

 

Hope I've helped a little. Sorry I couldn't get you the information I thought I was going to get.

[RPMS]

Pete writes:

quote

Someone used to make bearing spacers to put the small journal crank in the 350 block. To put it in the 400 block, you'd need an even bigger spacer.

 

Heya, Pete.

 

My understanding is that Clevite now makes a bearing specifically for the small journal crank to big journal block swap. It's thicker, so doesn't require a spacer. It seems that would be the easiest, best way to go.

 

quote

If that shop in Ventura CA still offers that 327/400 combo 353 kit, maybe they have something. Going with the Ford con rods too?

 

That's the plan. Of course, a lot can change in six months! The Hot Rod article on the AFR site mentioned Wayne's Engines in Riverside, CA. I haven't heard about one in Ventura doing the same thing. Could you tell me something more about that? Might save me some legwork!

 

And Ara writes:

quote:

---

Well, my buddy wasn't as much help as I had hoped. All I got for you was that both your block and heads were 350s used between 80-95.

 

Hey, Ara. Thanks for asking, anyway. It was nice of you to try.

 

I will take a guess and say since you've got a two bolt, appaently non-hyhdraulic block, your heads are the standard 72cc combustion chamber. With dish top pistons and a standard stroke this should put you somewhere in the low eights, compression wise.

---

 

I've got a set of 305 heads with ridiculously small chambers (58cc, I think?) It would certainly raise the compression ratio, but would that combination also self destruct? Is there any point in considering something like that, or is it a case of "just because it WILL fit, doesn't mean you should do it."?

 

Also, Ara, I think you're right about the aftermarket intake. Any benefits of Wieland over Holley?

[pparaska]

Scott, I'm sorry, I thought the AFR article said that the shop was in Ventura. My bad. Glad to hear you found that you can go all the way from the 2.30 mains crank into the 2.65 mains block with bearing inserts!

 

I've never seen any back to back test of the Holley Dual plane (300-36) to the Weiand Stealth. I've seen several tests with the Holley dual plane, and it always seems to do well down low as well as only giving up 10-15 or so hp up in the 6000+ rpm range to the Vic Jr. single plane.

[Guest Anonymous]

Scott,

Your pistons are the recessed head "P567" variety. With the open chamber heads you have around 8.0-1 comp.

The cam "Clevite 274" is the builders term for the stock 350 cam of anyones making.

This cam is a 194/204 @.050 with 398/420 lift. The combination is fairly well matched as is sits. This cam pulls from idle to around 4500 and then it is done.

The heads if stock have a 1.800 intake and 1.500 exhaust.

The 305 heads have the same valve sizes and would bump the compression to 9.5-1.

If you were to change the cam and use the 305 heads you would have an engine similar to what Summit offered (some time back)as a 300 hp.

I would suggest using the Melling Stage 2 performance cam which is 214/224 @.050, 440/465 lift on 112 degree lobe center. This cam with the higher compression gives a hard solid idle with good vacuum production. This cam is effectively two stages hotter than the cam you have now, which raise the upper RPM pull up to 5000+.

If you can hook it up, you should be good for high thirteen's in the quarter.

Most other bolt ons (by themselves) will add only marginal HP increases to the low compression engine.

The Edelbrock Performer manifold is set up to use the Q-jet as cast, while most all others will require a square bore Holley carb. This manifold will have slightly larger ports, and I would suggest procuring it in advance, and then while the 305 heads are off the motor, match port the intakes using the stock gasket for each as template.

This motor will probably require premium fuel as well.

This combination will make bald tires as quickly as most any other setup simply because of the low end torque production.

Cooling it will be a snap, and even 1.5 inch block huggers will do the trick.

[Cyind]

Try http://www.mortec.com/castnum.htm

 

Shows CAST # 14093638 87-95 350 2 or 4 Roller or flat tappet cam 0ne piece rear seal...

 

CAST # 14102191 87-up 350

[Guest super280z]

Idaho's right about the potential performance of that motor. im not too sure about the CR eing as low as 8.1. my opinon and fact, 305 heads dont flow worth of crap. you'd get a higher comp ratio but what good does it do? if heads dont flow you make slackin power.

 

the exhaust ports on the heads are round port. did anyone think about the fact that they might be vortec heads? also, GMPP makes late model 4 barrel intakes for good prices so i wouldnt go messing with drilling one.

 

this motor sounds very similar to one you'd see in a Z71 silverado. i'd assume that you have a stock rebuild long block from a chevy truck.

 

suggestions? sure, it all depends on your budget. stock bottom end - ported/milled heads, definately bump compression 9.5.1 - 10.1 or so, 268-282* cam, 1-5/8" - 1-3/4" headers, 4 barrel intake, good carb, so on and so on... have fun with it.

[DavyZ]

quote:

---

Originally posted by Super280z:

...my opinon and fact, 305 heads dont flow worth of crap. you'd get a higher comp ratio but what good does it do? if heads dont flow you make slackin power...

---

 

The 305 heads shine when you have an extremely limited budget and no real way of cheaply bumping compression. I would choose the 58cc 305 heads over the 76cc smog heads I have now on my Camaro motor, all things being equal. The higher compression would actually help to bump horsepower over what I have now. Obviously, Vortec heads or double hump heads would be better, but if the 305 heads are practically free (which they are at some wrecking yards) and the only alternative is the stock smog 76cc heads, well, the 305s start to look pretty good.

 

Davy