lamune engine build (can engineer guy build a motor?)

Starting a thread on this since I'm actually starting to do something.

I got a core motor out of a 95 9C1 Caprice that had "less than 100,000 miles" but had been sitting outside for an unknown period of time.

One of my co-workers, as it turns out, has a real workshop. He also builds big blocks for circle track racing and other uses, and he's helping out with space in the shop and time. So far we've disassembled the motor and put the block in the parts washer for an entire day. It's on a stand and we inspected it, and the block is fine.

The plan is to build a 383 stroker with this block. Since the wagon is mainly a family truckster for general road trip use I'm not planning on anything extreme, just something a little "better". Beyond that we're still in the prep and plan stage.

Time's not critical so I don't expect very rapid progress on this, but I will keep things updated when there's something interesting to report.

Due to rainwater infiltration the stock iron heads are basically shot (or, the amount of money required to fix them is probably not good money spent) and all the internal parts are either rust-damaged or not usable for a 383 build anyway.

So, here we are, starting with an empty block!

As it is a '95, do I understand correctly , that this is an LT1 build, not a traditional SBC build?

I just want to keep it as stock as possible to avoid unknowns. Also I might be called in for smog testing at some point.

Nice ! I am thinking about doing something similar so I will be following your build with keen interest .

I didn't do much aside from cleaning. Bead blaster works wonders on some of these parts.

I found there's a born-on date on the bottom of the block, which was a neat surprise. Looks to me like it says 8:04/24/95 19:19

Didn't do much this weekend, got parts organized and some things cleaned. I can read the engine code clearly now, it's V0424XPC.

- GM "white" oil pump spring p/n 3848911
- oil pump driveshafts: Melling IS-55E, Arp 134-7901

since you're changing the camshaft. Remove the 4 bolts holding the bottom plate on the pump housing, then you can punch out the small roll pin that retains the spring. While you're in there don't forget to weld the pick-up tube onto the pump. Also, drill housing to open the outlet port to main bearing cup & deburr the edges.

Timing cover gasket set: Fel-pro TCS 45956
head gasket: Mr Gasket 5716 (.026")

Thanks Jason - the kit comes with a new Melling pump, so we're probably going to use that. Given how much water got into this motor, I'll take the old pump apart and see what's in there. It may be interesting.

Is it a high volume pump ? They are generally not recommended.

Nope, stock volume and stock pressure.

sweet. I'd still get the spring though.

Jason, what did you want me to do? Take the pressure relief spring out of the stock unit and swap it, or remove it completely, or something else?

use gm p/n 3848911

What does the pressure relief get set to if you use that spring?

More generically, I'm not sure what you're suggesting I do. More pressure? Less? Why? What's wrong with the stock volume/pressure?

raises it to about 70psi.  Use the spring, it's 5$ and everything is apart anyway.

Got it, thanks Jason

""What's wrong with the stock volume/pressure?""

That's unclear. My teardown and inspection of the old motor seems to indicate there's no problem with stock pressure and volume. Maybe Jason can elaborate on what problem the white spring is going to solve or prevent. I ordered one anyway, it's only a few bucks.

I took the original oil pump apart to see what that's like. The oil inside looked like a mocha latte due to water intrusion but there wasn't any rust or damage aside from a few teeth with slightly nicked edges probably from a chunk of something that ran through it. I disassembled it and ran it through the parts washer and it seems like it'd be ready for another 100k miles if I wanted to reuse it.

The kit, if I can ever get Lance on the phone to order one, comes with a Melling 155 which is probably what the pump I just took apart is.

On another note, I stumbled onto a NOS distributor. At least, I think it is. The box has been opened at least twice. I see no evidence of it ever being run, there's no mark on the shaft or the terminals. There's a partial date on the cap but the last digit isn't present, but it's between 2000 and 2009.

I wonder if this thing is actually new or if it's a refurb.



The rings have some green stuff on them. A little surface rust on the shaft. The drive part looks really dirty, I'm not sure if that means anything or if its how these things normally look.

I have a good used one that has been sitting for years, and the shaft and O-rings look like new.

The green stuff on the O-rings is a material identifier put on by the O-ring manufacturer. You probably have a shopworn NOS part. You might want to polish the round sealing surface on the drive spindle with something like fine rubbing compound before installation.

The o-rings have the blue product on it even when you buy them separate from GM

The oil pump displaces the same volume of oil per revolution independent of speed or pressure. The relief spring just controls the pressure at which it bypasses that oil back into the pan rather than sending it up through the motor. Considering the stock spring is probably fatigued, I don't know why you wouldn't change the spring that lowers the threshold of having oil bypass back to the pan without lubricating anything. If the pump is displacing oil, I'd rather it be lubricating my engine. Plus 70# isn't high enough to cause problems.

Perhaps the oxidation on the purely due to humidity. It's from the South, so that may explain it. I was thinking of maybe some toothpaste and a dremel buffing wheel would be pretty safe to remove that rust. At least it won't get any cavities then.

Looks like the date on the cap is from 2000.

Thanks Jason, so that makes sense- no point using the 20 year old spring on the old pump. If we use a new pump, I'm not sure it's going to do much. I don't see a spec that says what a new one is supposed to open the bypass at.

I know you can buy a pink spring from melling that's 70 lb. I don't know if that's the one that's installed on your pump from the factory. If it is, you'd be fine with it. If you're unsure, stick with the GM spring.

Excessive oil pressure is not needed on most engines. It only puts more stress on the pump and gears/ shaft that drives it. Excessive pressure also costs horse power, due to added parasitic drag on the pump. With proper bearing clearances, the stock replacement pump, with the spring it comes with will be fine.

Bumping the pressure 10-15 psi to 70 psi isn't excessive. I don't know why you wouldn't want to use it, since it's probably reasonable to assume his engine -on a heads/cam car- will be spending more time at higher RPM than most stock B-bodies. My opinion, if you're putting in a new pump or doing a cam, put in the spring. It came one some stock F-bodies.

But yes, you'd probably be ok running the stock spring and buying a beer with the 3$ you saved. I'm pretty sure someone on the forum has an expression for this.

I didn't think 70 was excessive since stock is something like 50-60 from what I've been told.

Golden rule is of course 10PSI per 1000 RPM, and 7000 RPM is not a design goal here, so I doubt it'd make much difference.

Jason, we're building a 600-3000 RPM motor, not a free-rev RPM monster. And yes some of the parts I'm using are overkill/unecessary but I want to do some of these things just for fun. Nick's Law definitely applies.

I didn't do anything to the motor this week. Still waiting on parts and my friend was out so the shop was close this weekend. I did have time to disassemble, inspect, clean and then seal up the NOS distributor I found.

Pencil eraser worked great on the gray oxidation, and a little light steel wool and oil rub took off the surface rust.

Well, the parts are here!

Here's a rundown of the major components in the kit:

Crank: PBM 70002
Pistons: Sealed Power H859CP cast, dished +12cc, 4.030"
Rods: PBM CR5703 (has SCAT57 on the beam, are they SCAT rods?)
Cam: Erson E119826 276 duration, .480 lift
Rings: Hastings 2M139030
Rockers: PRW 0835004 steel, roller tip, 1.6 ratio



Lots of parts!

who recommended that Erson  cam to you ?  208/214 .512/512 on a 114 LSA ? F that.

if you're going through all the trouble of building an engine, don't use that cam.  You are leaving a LOT on the table, and will not be pleased.  Don't know how much you paid for it, but get a refund and buy a proper cam.  If you don't want one of the many off the shelf cams available for about $300 get a custom cam from Lloyd Elliott.  I think it's about $350, optimized for YOUR setup.  OR send your stock cam to get reground by Delta Cams in Tacoma, near you.

http://elliottsportworks.com/?page_id=32

edit: I'm of the less-is-more mindset when it comes to cams. I like to go with a milder cam as they are more fun to drive, but your cam is just inappropriately mild.

Yeah, wow. That's not even worth installing. Almost no overlap, huge lobe separation... pick another cam before you end up doing it twice. That's not even going to sound like you put a cam in it.


Not that it's a hard job, but dang.

Of the cams available that one was the most stock-like. I'm not opposed to changing it, but the goal was a smooth running idle to 3000 rpm motor with more cubes for low end torque, and of the cams he had to pick from that's what Motorsports Unlimited recommended for this build.

The next cam up would be a .480 lift, 218/226 duration with 112 degrees lobe separation.

He was debating the merits of going with either of those two cams but upon more discussion decided the "stage 1" as he called it would be the smoother, more appropriate highway driving cam.

Feel free to discuss, I'm interested in what's worked well on other builds.

Jason, which of the cams from Elliot's did you like? I see the two on top there:

212/222 .563/.562 114 LSA. – Idle-5800 RPM
“Sleeper cam” with smooth idle improving HP and TQ everywhere.

218/224 .570/.565 111 LSA. – 1500-6000 RPM
Great low and mid range power with very mild idle and will easily pass emissions. Works with
stock gear and factory converter. Comparable to popular Crane 227 cam and GM 845 cam.

on a stroker, I'd be going for the 2nd one, provided your springs can handle the lift. I'd just pass on the 1st one. If you want something that mild, buy the used 109821 on amazon.com.
Honestly, you can call LE. He's super knowledgeable and has other grinds. Recently, for my 350 with LE1 heads he suggested something a bit more aggressive then either of those. I told him I found the 228/235 from LE too aggressive in my stroker with LE2 heads (most people find it quite streetable.) so he suggested a cam that was a modern version of the old LPE 211/219 cam.

Hey I think I found where my oil leak was coming from Nick, I pulled the leaking part out and it stopped!



The "Cop block" has an issue in a bore that even .030 over doesn't solve to my satisfaction so I'm well into Plan B at this point.

Hey all, I haven't updated in a long time since nothing happened for a long time... getting someone to machine a block is really hard and slow these days...

In any case we've gotten to the point of dropping the new crank into the block, installing the #1,2,7,8 pistons and measuring the deck height.

The piston crowns sit about .020" below the deck, and the variance across the four corners is .0025". My mentor on the project says that's not enough to worry about for a station wagon application. I'll go with that opinion.

Piston ring gap clearance is about .002" beyond what the FSM says a new ring should be, which is odd, but again, didn't raise any concerns.

Since we didn't see anything alarming we're next going to clean up the deck surface a bit, put the block back in the parts washer, dry, mask, and paint it and then start assembling the bottom end.

This weekend, got the piston rings installed, put the pistons in the block, and did the cam degreeing.

1, 3, 4+1... I like it. lol

Yeah, I made a slight numbering error there, obviously.

Next week, we should be able to put the heads on!

It's coming along,.

Personally i would have coated the pistons, and decked the block for zero,
and filed my own ring gaps,.

Yeah Nick, next build, that would definitely be on the list. I'm glad I opted not to zero deck it this time as my CR works out to 11.2:1 with the pistons down .024" so at zero I think my ratio would be insane.

This week we got the heads installed. Next week we should be setting up the valvetrain.

11.2?   Stock pistons? Stock heads with what cc'?
What head gasket?
What stroke did you use?  What rods?
Also you need to research static and dynamic compression ratios,.

Personally when i build, the deck surfaces are always trued up, and a line hone is important to me,.before the block is bored.

I'm sure you will be happy with yours,. Don't get hung up on oil pressure,.you won't spin it much higher than 6500rpm,. The head studs are expensive, a little over kill for your build,. Did you stud the bottom end too?

Any work done to those heads? The stock steel head flows better than a stock aluminum.

Good work so far, we all have to learn at some point. My first engine rebuild made it about 5 miles.

Nick, I went over that again and short answer is- I need to call Mahle and get the real spec on the volume of the valve reliefs. I found a number online (5cc) that is probably wrong (shoulda measured that before I put the pistons in I guess)

That number makes a huge difference and I think that 5 is probably too small. I'll get an answer and update my CR.

The number should be close to (and a little higher than) 10.8:1, as I have the stock pistons at .030 over with the stock crank and a 53cc head off a Corvette (which measured closer to 52.5cc now after being milled)

94Woody wrote:

Any work done to those heads? The stock steel head flows better than a stock aluminum.

Good work so far, we all have to learn at some point. My first engine rebuild made it about 5 miles.

Nope, just new guides and springs and cleaned up. Either one flows enough for this build.

I called Mahle tech support and they have no published spec for the valve relief volume on those series of pistons.

I ordered another piston for measurement since that's cheaper and easier than pulling the head and piston and replacing the gasket. I'll see what I come up with. However working backwards from the published compression ratio for the motor, 6cc is the volume I come up with. Then going forward with that, adding the .030 overbore and the .5cc loss from the head milling, I get 11:1 which seems more sensible.

Woody, I forgot to ask - what killed your rebuild after 5 miles? Got me a little nervous...

This past week we hit a snag- the pushrods which were supposed to be (and are marked) 7.200" actually are 7.218" long and the rockers don't rock around the centerline of the valve stem. Working on getting that figured out. Using an adjustable pushrod gauge it's looking like 7.200" might be a little too long. Working on getting that sorted out as well.

I did measure the valve reliefs and came up with 6cc however, so that's good. Still puts me at 11:1 give or take a little bit.

make sure you push rods don't have any sections that are machined down, had the 454 in my dually rebuilt and one day getting off the highway after cruising at 75mph the engine suddenly had a miss, got home checked things out and eventually popped the valve covers off and found a pushrod had actually bent where it had been machined down thinner then the rest for some reason.

Hah! Well, that's unexpected. I'll double check the pushrods once I get the right length!

I also wanted to update on the ring gap issue I noted earlier. The ring gap was slightly bigger than the FSM specced out, but the little piece of paper from Mahle in the ring box gave a ring gap spec that was exactly what I measured. So Mahle says my gap is correct even if the FSM doesn't.

A little extra ring gap is not a big deal. My 454 called for 0.020, and I am at 0.024. If you are making more power than stock, then the larger gap is a good thing. If you ever put a power adder on, it will be the best thing you did. You do not want the rings to bind in the cylinder, and decapitate your piston.

Use the adjustable push rod, and set the rocker on the valve stem where you want it to be, then adjust the push rod to fit. Get the nearest one to the length you measure.

You can make slight adjustments in the CR with different thickness head gaskets. The reason for knowing your CR is to help determine what range of octane rate you can use without detonation.

Yep Fred - my mentor didn't seem terribly concerned about the gap so I wasn't worried either, but finding the note in the box at least cleared up the difference.

We did use an adjustable rod but I wasn't clear on the process, so I'll re-do it with him and make sure I understand it. He came to the conclusion that we should go one size down from stock but I want to validate that before I order anything.

And yes I was just making sure that the CR wasn't so crazy that I couldn't run on premium fuel. I can live with that, but if I have to run race gas that might be problematic. 10.8 is where I should be if everything was stock so 11 doesn't seem too extreme of a change.

I had to use different rockers on my 454. The stock Chevy ones would not land on the center of the valve stem, no matter what I did. I ended up with Ford rocker arms. Depending on who made the heads, could make a difference with the rocker arms.

The ring gap is not as important as the placement of the gap in relation to the other gaps. The first, and second should be 120 deg apart, and the upper, and lower oil control should be 180 deg apart, but not aligned with the compression rings.

Aluminum heads should allow you to run a slightly higher compression ratio for the same octane as iron heads. I do not know if you have ever experienced an engine knocking, but if you disconnect the knock sensor, and it knocks, it will sound like marbles rattling around under the hood.