218 or 230

[DollyDodge]

I need some help (what's new eh?). The machine shop has finally gotten around to rebuilding the engine ( he has only had it for 10 months). He says it has a 230 not the 218. My truck is a B-2-C and the book says it should be a 218. How does one tell which engine it is? The book says the bore size is the same but the stroke is the difference if I understand correctly. I thought I knew all about the truck but we the mechanic says the crank has been turned and the cylinders have been bored at least once. Some strange things have been done to the truck for example, the flywheel was welded to the crank. Also the bell housing has a 1953 casting date so something has been modified on the old girl. Even though the truck has been in my family since new it is apparent we don't have an accurate memory for all that has been done to it. Is there a way to determine whether the engine is a 218 or 230 that I can do?

Edited September 26, 2012 by DollyDodge

[Dave72dt]

You'd think the crank would have a number on it somewhere that you can reference.. A competant machine shop should be able to tell you the stroke or what they're basing the size on. As long as the bore sizes were the same when new, the stroke is the determining factor. Unless the crank has been offset ground (unlikely), the number should match either the 218 or the 230.

[DollyDodge]

I didn't ask the mechanic how he determined the size. He is very competent and has a good reputation, and I didn't think about what he said until I got home and remembered my truck was suppose to have the 218. I will ask him tomorrow. I just want to make sure he is correct. He said I will need to get a new crank since the one I have can't be turned any more. Vintage power wagon refurbished 230 cranks are $550. I want to make sure I get the correct crank.

[B1B Keven]

What number is stamped on the block?

Above the generator, right below the head.

[JBNeal]

what is the current bore vs. the standard bore? If the bore has been increased, then that 218 can become a 230 without modifying the stroke, but it would be more likely that the displacement is somewhar in between. A machine shop that doesn't need to be motivated to do a good job should be able to determine bore, stroke, crankshaft etc. But the flywheel welded to the crankshaft? YIKES...hope they balanced the thing, excessive vibration can be the death of any casting.

From what I've read, a 218 can be changed over to a 230 by changing the crankshaft and connecting rods. Like any close tolerance machine, every part dimension has to be verified to eliminate any possible interference. It's easy to get in a hurry and start throwing parts at the mess and hope that it works. From my experience, a good machine shop can botch a 'small' job just as easily & quickly as a wet-behind-the-ears shadetree mechanic. The end result is the same: a big pile of disappointment on top of an empty bank account. These are quite the motivators for the hobbyist to become very involved in a project that is being sub-contracted

[DollyDodge]

I will check the block number. What will it tell me?

I am involved with the shop. My problem is I don't always know what to ask, hence my questions in here:)

The shop I am using has done quite a few flat heads over the years, one reason I picked him, also he is the only shop in town, the next closest is 2.5 hours away.

[54Illinois]

I would shop around for a crank. Ebay has some sometimes, as well as Craigslist.

Also, measure the length of one of the rods...I have both sizes, and I could compare.

[DollyDodge]

I got the number off some photos I have. It is T172-56647

[Frank Ollian]

If you have the 230 crank and rods I think you also need the 230 flywheel, can yours be salvaged?

[B1B Keven]

T172, 218ci, 23 inches, Dodge Truck, B-2-B, 1950

You need to measure the stroke. Maybe someone has put a 230 crank in it?

[JBNeal]

The condition of the block needs to be verified by checking for cracks by magnafluxing after hot-tanking (chemical cleaning). The cylinder bores need to be checked for taper, as excessive taper will require sleeving or condemnation of the block. Once the block is cleared for rework, then focus on the guts of the motor. If the block is useless, better to find out before investing too much into it

[DollyDodge]

The block has excessive taper, he said it needs to be sleeved.

I am now thoroughly confused. My truck Door plate and serial number show it to be a B-2-C. I checked my bunn book, and it agrees with the post below, and it says the 172 is for a B-2-B.

I ran the truck like it is as far as the crank and flywheel the last two years, and as far as I know the engine it has is the same set up it had since at least 1970. I drove it in High School and College.

Oh well the mystery continues.

[Young Ed]

I've never seen a # on the crank but there is a # on the rods. To convert a 218 to a 230 you swap the crank and rods. It seems unlikely the crank has been turned enough to be useless and same for the cylinders. Heck before paying 550 for a new crank check and see what it costs to have the journals spray welded and remachined.

[DollyDodge]

I think I am in over my head a bit. I will visit with him today. He was going to check around and see if he could find a cheaper crank, I was going to call Roberts too and see what he charges for a crank. Part of the issue with my crank is it had spun a bearing and that journal is also messed up. Thanks for all the input. What numbers should be on the rods?

[Young Ed]

What numbers should be on the rods?

They have casting numbers that dictate their original use. I've seen others look them up but I don't have that resource personally.

[54Illinois]

Good move on moving slowly...I can check rod numbers over at the shop.

[DollyDodge]

I will get the rod numbers today.

[Young Ed]

Good move on moving slowly...I can check rod numbers over at the shop.

What type of reference do you have that shows them?

[ggdad1951]

if roberts can't help VPW has cranks supposedly...

[DollyDodge]

I just spoke with Roberts and he doesn't have any, I then called VPW and he has both 218 and 230, but as I mentioned VPW wants $550 for them, and they are not turned. I found one on eBay for $100 but I am not sure it is correct. both Roberts and VPW were very helpful with the 218 versus 230 issue. VPW said if I give him the crank casting number or the rod numbers he could tell me what I have.

[B1B Keven]

Don't know if this will help.

This rod is from a 218.

[DollyDodge]

Thanks for the help. I visited with the machinest and we looked up the casting number on the crank and it is a 218. He told me how he thought it was a 230 but I forget what he said, in any event I think we are ok. I feel much better after talking to him. He was fully aware of the similarities between 218 and 230 and said he has done several 218 to 230 coversions over his career. He thinks he can get a crank for significantly less than $550. I hope so:)

[John-T-53]

Motor Warehouse in Sacramento can supply your shop with a reconditioned crank for about $500, ready to go. Have your guy call them and talk to DK, the owner. (916) 920-2221 x18 Their cranks are known to be very nice. Their rods, however can be off a bit and need touching up (as I experienced).

The crank and rods have casting numbers that your machinist should be able to look up in the AERA book.

I recently went through this, and here's some rod casting numbers and dimensions:

218 rod: 617925 7.937" c to c distance

218, 230 rod: 954408 7.810" c to c dist

Do you have your old crank forging #? A 230 crank I recently sourced has a number 868929, however the numbers vary among years.

Good luck!

[DollyDodge]

Thanks again for all the information, it is very helpfull. There sure isn't much difference between the rod lengths and strokes for the 218 and 230. I wonder why they bothered, and just didn't make all 230s?

[54Illinois]

What type of reference do you have that shows them?

The numbers should be on the rod.