engine builder question

[70shortwide]

I have never had an engine rebuilt before, so please bear with me. Ive gotten one quote from a machine shop that Ive decided not to go with, for other reasons.how much should balancing cost (approximately, of course)(maybe a range of cost)? how much should it cost to have an engine assembled AFTER all the machine work is done?

My engine is a 521 (460 based stroker). very mild, iron headed. the engine is being rebuilt as I broke a rod in it last summer. Im reusing the crank, block, and heads. I upgraded the rods and will have custom pistons soon.

let me know if you need more info, just trying to get an idea. Im going to contact a few people about it this week and would like to have a close estimation of what they are going to say to me. I know every shop will be different, but I want to make sure Im getting in the right ballpark.

[averagef250]

A basic balance job should run in the $250-$300 labor range, that includes polishing the crank after balancing. Now where it gets complex is time and materials for balancing. If you have a funky motor, like aftermarket crank and rods that weren't meant to go together and your crank is too light the shop needs to install mallory. Mallory is friggin expensive and it takes a good deal of precise work to install it correctly. Think about what it actually takes to fixture a crankshaft in a mill, bore a precise hole through a throw in just the right spot and press in mallory.

I've had over $600 tied up into custom balance jobs in the past.

If your shop doesn't use mallory run away from them. Some shops have some scary balancing practices, I've seen rusty steel plate torch cut out and MIG welded to a cast iron chevy 400 crank before, scary crap some shops do!

[70_F100]

Having broken a rod, I'm pretty sure I wouldn't want to re-use that crank, even if it's been magnafluxed.

There's a pretty substantial probability that there's at least some metal fatigue, if not some fracturing.

[70shortwide]

Im not sure about that, It hasnt been brought up to me. definately something Ill ask more about when I talk to someone about this thing. the crank was sent in to have the thrust surface built back up, they found it to be bent when they had it. they straightened it and gave it a clean bill of health.

[cdeal28078]

As easy as a stock crank is to find I would not risk it, especially on a non stock engine. Bet you could get a used crank out of a running engine in a pull a part for less than $50.
I once tore apart a 351C that had thrown a rod. The bore only had a small score at the very bottom of the cylinder but the rod was broke about 1" from the crank and that helped. It broke the camshaft behind the 1st bearing also. A lot of twisting torque went somewhere and everywhere when it went south. You are going to put a lot of money in that engine especially if you are balancing it. Why take the chance to save a very little bit of money.
clint

[averagef250]

Having broken a rod, I'm pretty sure I wouldn't want to re-use that crank, even if it's been magnafluxed.

There's a pretty substantial probability that there's at least some metal fatigue, if not some fracturing.

I think it's an experienced judgement call based on the crank material and how the rod failed.

[Dragon]

I would get a crank and rod kit already for any stroker. As a builder years ago balancing was the biggest headache. I would rather port and polish chebie heads than add metal to a crank. We balanced in the 80s for $500. All total labor with all the die grinder work and other FE and racing tricks done by hand with all your parts would cost you $1000 back then. We had added value service though we ported the intake to match with reversion edges and curve the dizzy to work with the cam. Silly but important stuff. I ground so much metal off one block to get smooth oil drain back and all flash removal that my t-shirts turned rust in the wash. My blood has great iron content.

Never use stock rods and cast crank on a stoker.

[70_F100]

Exactly...

[Montana71-F100]

As long as you have it apart, consider assembling it yourself. A rod bearing went out on mine and I'm no mechanic but I overhauled it using a Clymer manual. I had it bored and put in a different crank because mine was cracked. It was a great learning experience and I'm glad I did it. That was before I knew about this forum but it would have been a great resource. The only downside is there isn't any guarantee, so if you screw up, it's on your shoulders. On the other hand, I followed the book and knew everything was done the way it was supposed to and it's been running fine for a couple of years now.

[Dragon]

Sorry to say he is building a stroker and that is not the place to learn. Also taking it to a non 385 or FE specialist but a chebie or Hemi machinist will be the death of it. Chebies need several things to get big cranks in and Hemis need much stronger parts than normal.

I have gotten 526 out of a Hemi and on Nitro we blew the driver's side head off and the bottom lived. 512 out of a 454 and the bottom end dropped when it went on Gas and a 504 out of a 427 FE and lasted the season on minor rebuilds and 2 dropped valves and one piston skirt.

Strokers are fun but fragile. A lot of rotating mass with the weight on the outer edge of the rotation really whips the crank around. Any time I go over a 4.15 crank it stops becoming a weekend toy and gets 4 bolt mains the best crank and the best rods with the strongest bolts for the main caps and rods.

[Montana71-F100]

Good point. Thanks for the explanation.

[FORD428CJ]

Never use stock rods and cast crank on a stoker.

Cast stroker cranks are fine and with good results. I wouldn't hesitate to use one. There are a bunch of people using them in street, street/strip and all out strip. Not quite a true statement....

[bb429power]

I would get a crank and rod kit already for any stroker. As a builder years ago balancing was the biggest headache. I would rather port and polish chebie heads than add metal to a crank. We balanced in the 80s for $500. All total labor with all the die grinder work and other FE and racing tricks done by hand with all your parts would cost you $1000 back then. We had added value service though we ported the intake to match with reversion edges and curve the dizzy to work with the cam. Silly but important stuff. I ground so much metal off one block to get smooth oil drain back and all flash removal that my t-shirts turned rust in the wash. My blood has great iron content.

Never use stock rods and cast crank on a stoker.

Why can't you use stock rods on a cast crank? Or is that just for a stroker? That's what I'm doing but the rods were ground down for strength and its not a stroker, its a 429 but I'm putting a 460 crank in it. Anyways, here's a price list from my builder.
Go to "services" then click "ok" for everything else.
http://champion-performance.com/

[bb429power]

Never use stock rods and cast crank on a stoker.

Cast stroker cranks are fine and with good results. I wouldn't hesitate to use one. There are a bunch of people using them in street, street/strip and all out strip. Not quite a true statement....

I just read this. But yeah, that's what I thought.

[Dragon]

Stock rods work good in the arena for which they are designed. Cast can work but I don't want to rebuild the bottom end because the cast crank cracked. Been there and done that. I have had two very expensive cast cranks in two different engine styles in 2 different displacement crack across the main journals. What a mess. Converting a 429 to a 460 is not really making a stroker. It is drop in factory parts.