1955 12 Valve NAPCO Clone

[6BT 56]

Hi Luther

Crummy abt the # 6. I like what diesel wrencher said . Maby just give it a hone, get a std piston and run the old girl. I worked with a engine builder quite a few years ago and the boss always said there is nothing wrong with patching sumtin up to get going . Just dont mix parts. Ie if your running old , run old. just dont go mixing new and old and expect it to run like it's all new.

Hopefully this dosent set you bak too much as you have been doing real good.

[Luther Grimace]

I don't think it does have the fuel system. No injection pump, manifold or turbo either. Would I run into any trouble running a p pump long block with the VE pump? I will get some pics of that bore and post em. Could they bore just #6 without me having to disassemble the whole engine?
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[Dieselwrencher]

Originally Posted by Luther Grimace

I don't think it does have the fuel system. No injection pump, manifold or turbo either. Would I run into any trouble running a p pump long block with the VE pump? I will get some pics of that bore and post em. Could they bore just #6 without me having to disassemble the whole engine?
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No real trouble. You will have to pull the cam and swap gear housings. Your nozzles are 9mm and P-pump are 7mm so you will need to run adapters and they are kind of expensive now. The pistons on the p-pump engines have smaller bowls, so you'll have to becareful with timing and such to make sure you aren't spraying out of the bowl. On machining, I really don't like boring one hole. It just makes them that much more out of balance. You will need to pull the entire engine down. The reason is, metal shavings are going to get everywhere when they cut that cylinder wall. I don't know about you, but I don't want metal shavings near any of my engine components. However, you can have a sleeve installed, aquire a good used piston, and then get new rings and you are on to a cheap over haul. A good machine shop will bore/hone a block to fit the pistons you're running. That being said, he can match closely the piston to wall clearances on the other 5 so 6 will be close.

[Luther Grimace]

Originally Posted by Dieselwrencher

No real trouble. You will have to pull the cam and swap gear housings. Your nozzles are 9mm and P-pump are 7mm so you will need to run adapters and they are kind of expensive now. The pistons on the p-pump engines have smaller bowls, so you'll have to becareful with timing and such to make sure you aren't spraying out of the bowl. On machining, I really don't like boring one hole. It just makes them that much more out of balance. You will need to pull the entire engine down. The reason is, metal shavings are going to get everywhere when they cut that cylinder wall. I don't know about you, but I don't want metal shavings near any of my engine components. However, you can have a sleeve installed, aquire a good used piston, and then get new rings and you are on to a cheap over haul. A good machine shop will bore/hone a block to fit the pistons you're running. That being said, he can match closely the piston to wall clearances on the other 5 so 6 will be close.

Are you sure I have 9mm injectors? I thought intercooled trucks had the 7mm tips like the late models? I am very tempted to just get that long block. I have heard that you should swap cams, saying that I should stick the ve pump cam in the p pump engine. It's just comparing getting that one or machining mine and sleeving it which would prolly run me a lot too by the time I get all the gaskets also. And where do you get new head bolts from?
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[Dieselwrencher]

Originally Posted by Luther Grimace

Are you sure I have 9mm injectors? I thought intercooled trucks had the 7mm tips like the late models? I am very tempted to just get that long block. I have heard that you should swap cams, saying that I should stick the ve pump cam in the p pump engine. It's just comparing getting that one or machining mine and sleeving it which would prolly run me a lot too by the time I get all the gaskets also. And where do you get new head bolts from?
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Yep, yours should be 7mm. I thought for some dumb reason yours was a non IC. I've heard the VE engines have a better cam profile, but I've also heard they brake easier due to the smaller size behind the front journal. I haven't broken one, but know some guys that P-pumped their VE that did turning 4k in a puller. Since you have it out, if all of your tappets and lobes look good, I'd go ahead and use your cam. It can't hurt. If you want a price on any cummins parts, PM me and I'll get you a price on them.

[6BT 56]

Hi Luther.

Anything to report? How you maken out on the eng issue ?

[Luther Grimace]

Nothing to report. I'm waiting on some parts prices right now and just letting it fester. These old Cummins sure are expensive to repair. I am leaning more towards finding another engine because I feel like I would come out ahead if I did. My crank seems to have too much thrust from a life with a bad thrust bearing. By the time I buy a head gasket kit, head bolts, and piston with rings I will prolly be into it pretty seriously at price.

[RANDY COX]

awesome build I like the truck...and the panel..

[Luther Grimace]

Thanks Randy!

[6BT 56]

Have you thought any more abt just giving it a hone and a used piston and bolting it back together? I know it half assed and may not last forever but it would be running so you could get all the other bugs associated with this big of a build worked out . Then you can find a newer or better eng later . In the vids of the dodge off road it did seem to run ok even if it was noisey.

[Luther Grimace]

I have been weighing my options for the past couple of weeks and yesterday I pulled the trigger on a 98 long block. I am hoping I can sell the front timing case and recuperate some money. I am gonna swap my cam, timing case and VE pump onto it. I think I should come out pretty even by the time I'm done. From what I checked on just a head gasket replacement was going to $250-350 and that didn't even address my bad cylinder. My engine ran fine but the knock was annoyance. And if I try to sell it it would hold me back.
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[RockTonka]

Cool, you have a direction now, that's half the battle for me!

[1985-GMC]

Dieselwrencher will know for sure but I think the pistons in the 98 may have different bowls. The 1st gen inj have 145* spray patters and some 2nd gens do to but I think they also have 155*, and i'm assuming those would be in the later engines.

[Luther Grimace]

I am going to just use the long block as is so I will keep those injectors in there if my ve injector lines will connect to them?
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[1985-GMC]

They have different size threads, you could use the 2nd gen nozzles and first gen bodies but then you need the pop-off reset to ve pressures. Or I guess you could just put it together and run it with the spray pattern off a little. I would just get a p-pump. I'm sure Ryan will chime in soon but he hasn't been on in a few days so maybe he snowed in... or out.

[Luther Grimace]

Originally Posted by 1985-GMC

They have different size threads, you could use the 2nd gen nozzles and first gen bodies but then you need the pop-off reset to ve pressures. Or I guess you could just put it together and run it with the spray pattern off a little. I would just get a p-pump. I'm sure Ryan will chime in soon but he hasn't been on in a few days so maybe he snowed in... or out.

That stinks

I should have checked on that before I made my decision. I wonder if I would run into serious problems running VE injectors with the P pump pistons. I might check on putting the P pump tips on my VE bodies like you said.

[Luther Grimace]

I did some searching and I found out that this:

"The Cummins Non-intercooled engines (1989 through December 31, 1990) use a 9mm injector hole, with a 155 degree injector spray angle.
The piston bowls are shaped correspondingly, HOWEVER the (Lucas) POD injector (7mm hole) is the same spray pattern, as are the Marine 370 injectors (7mm hole).
Simply using the aformentioned shims will allow the use of 7mm injectors in the 9mm head.

Some people make a big deal out of the fact the the 9mm head has a definite cracking issue in the injector hole, and while they do tend to crack there and they do seep through the washers, they seldom ever do much more than seep a minute amount of compression.
To this point, personally, I have never seen them crack and have a coolant issue.

The spray angle on the '91.5-'93 INTERCOOLED injectors is 145 degrees.
The spray angle on the '94-'98 (pre 24 valve) injector is also 145 degrees.

The injector BODIES are different where the injector line fitting attaches to the body.
The '94-'98 line fitting is larger than the '89-'93 style.

The tips (sometimes called "nozzles") interchange between the bodies on all years, but the "pop pressures" (Initial line pressure required to move the pintle) differs between the 2 different pump styles (89-'93 VE vs. '94-'98 P-7100).

I (and others) consider the Non-Intercooled VE engine to be the "Hot Rod" engine of the VE line, as it has the largest stock injectors, flow wise, (4x.013) of all the 12 valve engines, as well as a bit more agressive cam profile.
As stock, the non-intercooled VE pump is usually very conservatively tuned, with much more capacity available in it's adjustments.

The above specs are to be credited to the GREAT FOLKS at 1stGen.org.

Mark."

So it looks like I have lucked out on this. I can just reuse my injectors since I have a 91.5 year model. Sheww! I just made it by the skin of my teeth. I would like to possibly upgrade injectors down the road but I don't have the cash flow to do that now unless I unload some parts. I will have to check on selling these P Pump injectors and front timing housing.

[1985-GMC]

That's good news, and makes a little more since than them changing spray patterns in the middle of the p-pump second gens. It just depends where you get your info because one place will say one thing and and another will say something completely different. Sorry if I had you worried there! LOL

[Luther Grimace]

Oh no your good! I need folks like you to make sure I don't do something stupid. I hadn't even thought about the issues like connections to my pump and pop off pressure. I called a diesel place here in Alabama and he said they could check the nozzles on the 98 injectors and see if they are any bigger for more power. Thinking about using the bodies of the first gen injectors with the internals of the 98 injector with the pop off pressure adjusted for a VE pump. I am gonna check with Dieselwrencher because i'm sure he has prolly come across this problem.

[Luther Grimace]

Here is a pic of that new long block. Lord willing it will be in good shape because this truck is turning into an albatross.



I thought you guys might get a kick out of this. I have been working on my long term project while waiting on fundings for the new to me long block.

[1985-GMC]

Now that is awesome!

[6BT 56]

So is the 66? or 67? going to have a 6.2 as well? Maby add a turbo to that one . lol

[Luther Grimace]

Haha no this one is strictly Big Block Chevy gas guzzling power! And it's a 67.
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[6BT 56]

Is that your Impala SS as well??

[Luther Grimace]

That's the old man's.