Before I get started......bent crank.

[Zeke]

I think this is my first post here on this forum. I'm sure it won't be the last as I'm now venturing into the motor after doing a tremendous amount of body restoration and chassis work.

I bought a 2.4 T as a core so I could build up a motor to install while I work on the original S motor. I have acquired some 2.4 E P/C's as well as some 2.2 E P/C's. Will get to those later.

Meanwhile, in disassembling the T, I found the no. 5 rod bearing all on one side of the rod journal. Wasn't pretty. And, the crank is bent in the middle, right where that rod is. Not only that, but the oil pump is all but seized. I wondered why the darn thing was hard to turn with a socket on the pulley nut after the barrels were removed. Now I know.

So, what would be my next move? Toss this crank?

BTW, I did a search on "bent+crank" Nada. Please don't ask me how I checked the crank. It's bent, take my word.

EDIT: I did find some info using only the word "bent" and the word crank was in the text. Sometimes I wonder about the search. Anyway, someone says they have never seen a bent crank in 30 years unless it was dropped and someone else says a spun bearing can cause the crank to be warped, or "bent." They also said it's common to have cranks straightened.

OK, so I'll ask the question in different way, what is the more economical approach? The crank I have with the no. 5 journal has to be ground to under size or welded and ground to stock on the one journal. I haven't mic'd the others yet because I thought it might be toast. They all "look" good with no scoring. I've only got so much to spend on this temporary motor, but I want it to be nice enough to sell when I'm through with it and have a good feeling about that.

[camgrinder]

The crank can be repaired if it is not cracked.
Cost to do a single journal repair and nitride is usually over $450, if I remember right. Probably a better idea to toss this crank and find a useable core.

[Bobboloo]

Hi Milt,

If it were me and the motor was to be just for temp use I'd part the 2.4 out and find a decent running motor. You'll spend more rebuilding this motor than you can sell it for when it's done.

There's an add for a running 2.7 in the classifieds for $1000. It's in San Diego. That's less than what it will cost to rebuild this motor.

'74 2.7 complete motor for sale

I don't know if you've rebuilt a 911 motor before so maybe the 2.4 is your trial run but really they're quite easy. Nothing near the level of difficulty that you've already experienced with your body work. It's just a matter of disassembly, inspection, sublet machine shop work, buy parts and reassembly by the book.

Waynes book makes it really simple because it's laid out so methodically. Even if you've rebuilt motors before Waynes book is still comes in handy just for use as a mental checklist.

I think you're gonna really enjoy rebuilding that 2.2S and posting here. The rebuild forum is great. It's more business than the tech forum and contains a ton of info.

[Zeke]

Thanks, Bobby. I did see your issue with the case machine work and did quite a bit of reading here last night. Seems like there are some pitfalls and everything is not cut and dry.

Yes, this would be my first six and it is sort of a trial run. I have looked at other motors for sale, but they all seem to have some issue or another (or they wouldn't be for sale, LOL) The 2.7 mentioned needed a rebuild if I read the ad right. Now I know how expensive it CAN be to build a motor correctly. But, for this time, I'm gonna take a plug and play tack on the thing like MM does. I will find used parts as I go that are in spec and I will attempt to assemble the thing w/o a ton of outside machine work.

The most interesting thing I read last night was about the instability of the cases. That was not as issue when I built 914 Type IV motors. Those aluminum cases were great. I guess that's why AL cases from '78> are good.

[sammyg2]

I saw this in the recycler www.recycler.com

PORSCHE engine 2.4T... $1,700
2.4T mechanical fuel injection, sheet metal, oil cooler, injection pumps, stacks, no exhaust; needs rebuilding. E-mail for more info. Have pics..
$1,700.00 OBO

It's in LA, sounds like a good possibility. The MFI would be worth that much if it's in good condition. This isn't the engine you bought, is it?

Also in the recycler, I found a 356 crank that is standard size for $300. I thought those were worth their weight in gold.......

[Zeke]

Originally posted by sammyg2
I saw this in the recycler www.recycler.com

PORSCHE engine 2.4T... $1,700
2.4T mechanical fuel injection, sheet metal, oil cooler, injection pumps, stacks, no exhaust; needs rebuilding. E-mail for more info. Have pics..
$1,700.00 OBO

It's in LA, sounds like a good possibility. The MFI would be worth that much if it's in good condition. This isn't the engine you bought, is it?

Also in the recycler, I found a 356 crank that is standard size for $300. I thought those were worth their weight in gold.......

Sam, that 356 crank has been in there for ages. No, I didn't buy the 1700 one. I paid 300 for a complete 2.4 with MFI. It was full of water from sitting outside and the MFI pump is frozen. The TB's and butterflies are dead with corrosion. The cyls were very rusted iron T's and I tossed them. I also tossed the no. 5 rod and all the pistons. I have a replacement rod.

I don't want to waste anymore bandwidth on this being as how this is the "serious" forum. I do appreciate any advice. I can get good 2.4-2.7 cranks all day long for 300. I have everything to put this thing back together except a crank and some decent cams for some HP. I even have a NOS 2.2 E MFI pump. All but the consuambles, that is.

So, to the bottom line: I toss this crank then, right? Then buy bearings, gaskets, rings, have the rods and heads rebuilt and assemble. Oh, and I don't know what's up with the frozen oil pump, but it sounds like a good excuse to get a 3.0 one.

What I need is a shopping list to make sure I'm on the right track. This has to be an exercise in MM style ecomonics, yet I'm gonna try to be careful enough to watch what I am doing and not put together a time bomb. I will check the crank bore and other vital specs before hap-hazzardly throwing this together.

I realize what this discussion has become, a matter of engine rebuild theory. On one side is Wayne and on the other is MM. Frankly, for my purposes, the MM thing works. I just want the control I wouldn't have if they were actually doing it. I will go full tilt on the S motor once this is finished. Let's just call the cost of doing this one "education."

Now, for the shopping list, starting with a good used crank.....

A well known vendor has a pretty good rebuild kit that contains new chains and a lot of goodies. I think Pelican has a similar deal, but it's harder to understand from the catalogue exactly what you are getting. I will do my best to buy this stuff from Pelican. What about the "hardware kit?"

[sammyg2]

Inspecting parts and re-using them if they are good is not only economical, it is logical. Replacing everything just because you can get at it is indicitive of lack of mechanical knowledge IMO.
Knowing the difference between good and bad is the hard part for some folks.

Knowing it is bad and using it anyway is also a way to go, but only if you don't mind everyone bashing your company on the BBS

[Eagledriver]

Milt,

Welcome to the engine board. You'll be a great addition. I think you have a good plan. If you upgrade the pump you'll need the oil bypass mod on the case and new pressure relief springs/pistons. (you probably already know this, but just in case you don't). The rebuild kits can be a good deal. You need to shop around to get the one with just what you need. Some of the kits come with rings and you may not need them if the set of pistons/cylinders are good already.

Most of the time a mag case engine needs lots of machine work but for your purposes you probably don't need much except cleaning. The early engines with the biral cylinders were much easier on cases than the later 2.7 engines. I highly recommend reading the engine sections of Bruce Andersons 911 performance handbook and Waynes engine rebuild book. With these resources and our help you'll have no problems.

I've rebuilt engines with old rings and valve guides when they were within wear limits and they work fine. Obviously you won't get as long a life out of a motor with old parts though. You can plan to spend around 2000 dollars even without doing much machine work because parts and tools are so expensive.

-Andy

[Zeke]

Thank you both for your reply. I intend to start a new chapter and have a lot of fun with the rebuild. Sam, to address a point you made, I was examining the chain sprokets on the lay shaft and they are shot. One thing I do know is to not use a new chain with an old sproket. Better to use the old chain.

Chains were the life blood of karting and still are in many circumstances. To lose a chain is to lose a race, so a alot of attention is directed toward their condition. What we did was hold the chain out horizontally and see how much of an arch it produced. Holding a new chain next ot an old one was a great example of how much wear had occured. A lot of arch meant stretching and a stretched chain wears out new sprokets in no time.

I can't guage a double row chain because I have no experience and no new one to compare with. I'm adding sprockets to my shopping list and I know they ain't cheap if you buy them all. But, the motor won't run worth crap if the cam timing is all over the place, I know that too.

I'll keep looking at what I have.

I found some crankshaft exchange that has the 2.4-2.7 cranks ready to go for 300. Vellios in Lawndale CA on Manhattan Beach Blvd. Anyone know anything about this? BTW, this is Harry Vellios, not Geo.

[sammyg2]

Another trick is to lay an old chain next to a new one with both of them being stretched.
Look at the number of links and how they compare to each other. A little stretch on each link of the old chain will add up to be quite a bit longer by the time you get to the end.

I wonder if we can get O-ring chain for our cams? just kidding.

[Grady Clay]

Milt,

The 911 chains are just like the kart chains. Do two tests: First run the chain through three fingers feeling for a link that is stiff. Second, do a partial reassembly with the jackshaft in the case, chain housings, up through the cams. A stretched chain will have the idler arm lifted off the tensioner. New chains are relatively inexpensive.

First I would take the crank to the best crank people (plural) and listen to what they say. Next I would put a straight crank in the 2.4T case with good used mains and slowly torque the case while turning the crank. Stop if it tightens on the crank. That will give you an indication of the case condition.

Part out the 2.4T, even the bent crank has value to someone. If you do a MM on it, it may come back to haunt you. If it doesn’t work, many new parts are wasted.

I like the idea of buying a running engine, particularly if it is a MFI. That way you can do some diagnostics before any money changes hands. You have the savvy to spot something amiss.

Best,
Grady