Re: Why do so many frown upon swapping Chevy engines into Ol
CHRIS.O said:
...rebuilt a 455 and spent more money on the machine work and shortblock that I did on the whole Chevy 355 I just did with Dart Platinum heads. Literally, my whole chevy cost less, I'm talking new tin work, distributor, new heads, water pump, all machine work done to the engine, completely new engine. I rebuilt the shortblock on my Oldsmobile and had more cash into it than that Chevy...
There are a few things that need to be addressed here. First off, who did your machine work? How is it even possible that having one engine block machined could be less than another? Its the same labor and machinery to bore cylinders, align bore, and all the rest. It sounds to me like you might have gotten ripped off. Dollar for dollar should be the same cost no matter what block, as long as they are both cast iron V8. That's 8 cylinders bored on the SAME MACHINE. It's the same tools and same labor to measure and cut everything. Please clear this up.
If you have a machine shop telling you that it costs more to do an Olds block than a Chevy, you need an explanation on that. I would not use a machinist who charges different rates based on manufacturer. Never.
And that is the main cost difference. Machining. When I do a chevy small block (every so often I DO build one, but only for other people) the block machine work is what stretches the budget. I strip the engine down in my garage and then get to putting snap gauges and micrometers to everything. Whether it was the two 400 small blocks, a 305 or a 350, if that engine was built before 1987 it needed everything done, according to the math. I am always on a budget as I have said before, and I would never build an engine that was out of tolerance on the block. I might run loose, to the large end of the specs, but never outside the numbers.
Now, for my Buick and Olds builds, when I strip the block down, I rarely need major machine work done. That is where I save the money. Even if you don't have all the expensive measuring tools in your garage, you can do this. You take your block to a COMPETENT machine shop and have three things done. First, full steam cleaning and pressure cleaning of the block. Second, full checking for cracks. Third, full list of measurements. The machine shop can easily measure everything for you and then give you their recommendations of what should be done. Keep in mind the shop is in the business to make money, not to help you, so you need to be working with someone you can trust. I preferred to just have them clean and measure everything in the old days and then told them I will pick up the block from them when they are done. My story to them is that I have a few different blocks and I am deciding which to use based on budget. Once they realize that you are NOT over a barrel, they usually give you the honest measurements and you pay them for the hours it took them to measure it. Its money well spent.
Most of my Buick/Olds engines did not even require an overbore if I was going to use new pistons and rings. That just meant that once I got the measurements (or took them myself) it was a matter of honing each cylinder to be within the specs of piston-to-bore clearance in my manual. Some cylinders needed to be honed more, but I could get them all done with time, or have the machine shop do it if I took the pistons and the block to them. They can match hone each cylinder to the piston (like they do with new stuff after an overbore) and then you are withing spec without that machining cost of boring.
Of course that is IF your block qualifies, but most of mine have. Even the high mileage Buick/Olds stuff. Every old chevy block I have torn down with more than 50k miles didn't make spec. That's just reality. The 87 and newer blocks seem to make the grade much more often, especially the 96 and newer Vortec parts.
I have not had to have one Buick/Olds block align bored. I know some people have had to do it, but not me. They have always been in spec. Three out of four chevy engines that I did had to have it done. And that sucks mostly because then you have to buy a special length timing chain to make up for the fact that the cam and crank center lines are now closer together. Its not a big deal, but its a pain in the butt and it costs more money.
There is nothing special about a Vortec block per se, its just been built better at the foundry than the older ones were. Its the last of the GEN 1 small block chevy engines and the best made. That 350 block is a direct replacement for any small block chevy, it just uses a one piece rear main seal instead of the 85 and older one piece. It also is machined for the roller cam which saves you a ton of money in parts. The 87 and newer car engines (not pickup truck) have all been roller blocks when I tore them down. That includes the 87-88 Monte Carlo, all the 87 and up Camaro and Firebirds, and the
B-body cars too. Maybe some of them weren't, but all the ones I found were. Trucks you never really know about because the engines tend to get replaced more often. I have found quite a few that WERE roller blocks, but not factory installed that I could tell from the numbers. Replacement engines seem to go either way.
My Buick and Olds cranks are the same thing. Rarely do I HAVE to get them turned down. I have spent hours by hand with emery cloth just making them all the same spec, so that all the rod/main bearings have the same clearance. If you had to go to a machine shop to get it turned, it should be the same price as turning a chevy crank. More than one chevy small block crank has been condemned by the machine shop when I turned it in for being bent! Never had that happen with a Buick/Olds piece because most of them are either forged steel or heavy Nodular Iron. Ditto the rods, but I have had more Olds rods fail qualification than Buick parts. Stock chevy rods that are not PM are not getting run in my engines. I have seem too many failures, qualified or not, they are just not good pieces. The LT1 engines and some Vortecs (not sure if all) had PM rods and you can run the numbers to see if they are right ones or not online.
So really, for ME, I know when I do a Buick or Olds engine what I am getting into, and the prices are not bad enough to keep me from doing it. It seems like a lot of guys are getting sold a bill of goods at the machine shop and that maybe the machinist is making money more so than helping you fit your budget.
I hope that helps.
