LS swap . Done .

 

A 327 is built for upper RPMs...... Strokers are built for lugging.

For the cost of rebuilding an SBC, you can own 4 LS motors from low mileage wrecks

If you want to build it for the sake of building, that is one thing.

Not sure what compression calculator you used, however a 4" bore, 3.25" stroke, 64cc heads, +5cc pistons, 0.005 deck and 0.041 head gasket is 9.5:1

 

4 LS motors...but what about the wiring harness, the steam pipe added to the radiator, the radiator change (outlets are diff right?), the onboard electronics board, and the tune being loaded. Add in the fuel tank and pump. Am I missing any thing, as I have never done one? What about welding in new engine location mounts? The reason is because of all the associated items you need. Plus "from wrecks" if you can find one, right?

1) Am I missing any thing, as I have never done one?
2) From wrecks if you can find one, right?

I am asking because I always wanted a car with an LS, not to be difficult. Just sometimes I don't wanna take my whole car apart and start over just to put a fresh SBC in...

 

The 327 and 350 use the same length connecting rod but crown height is adjusted for stroke in wrist pin location which is studied as the term “compression height” this is called out for cataloged pistons.

Using a domed 350 piston to make up for the shorter stroke would be a poor solution as the dome interferes with flame travel and is always a less ideal solution, not that it isn’t done but there are other overriding circumstances that enter for specific point solutions where the loss of burn efficiency is compensated with high compression ratios that are not supported by modern gas station fuels. You will note that NASCAR engines where fuel burn is critical by rules limiting vehicle capacity and pit resources domed pistons on the physical layout at least the way dragsters do domes do not appear on these engines. Instead the piston is a flat top and combustion chambers are lower in volume. This makes for a fast and efficient burn that makes high sustained power on minimum fuel consumption with high RPM.

If a piston hit the head hard enough to bend a connecting rod there would be huge damage to the head at that cylinder. If not present either that isn’t the head that got hit or the rod bent for some other reason usually associated with high RPMs. The typical connecting rod failure starts with the rod bolts being stretched by the rod cap distorting under high loading this pinches the crank journal locking the two together failing that bearing and journal and bending if not breaking the rod. This kind of damage is quite evident when it happens just as the evidence of a piston to head collision is seen on them.

The 010 block is good to build on it is a thick casting used specifically by GM to build engines for high performance cars and highly loaded trucks, it frequently is found with factory 4 bolt mains.

If someone ran a roller cam in a non roller block and used dog bone lifters without a spider they obviously didn’t understand what they were doing or how and why this system works. The rest of this butcher build appears to verify they were in beyond their technical understanding.

As far as revs versus torque goes the 350 will wind to anyplace a 327 can go. This is more parts selection than the effects of stroke dimension.

Given the bent rod and the forces needed to do that plus the rotated and skidded lifter the entire engine is suspect of structural damage if not failure, this needs to be disassembled and throughly inspected for cracks and other damages.

If the castings come back as solid and the bores have enough material left in them that they will accept .030 to .040 over the stock 4.005 I’d build it as 383 stroker. You can purchase complete kits are piece it together on your own, we can help. Or put it back as a 350 and forget the 327 nonsense.

If you guys keep us in the loop especially before you spend money for stuff we can help, there’s a lot of experience here.

In terms of Scott’s suggesting an LS build this is best done by essentially purchasing a known good though written off donor vehicle then piecing out the driveline and computers with their wiring. You’ll need the maintenance manual for that vehicle. You can go other ways with aftermarket electronics but these can be costly.

Bogie

 

If your compression ratio calculation came up with a number in the 7's even though the piston has a 5cc dome, that has to mean the pistons are made with a compression height for use with a 3.48" stroke 350 crank and not the 3.25" stroke 327 crank.
This scenario is seen when the initial builder/parts chooser doesn't understand compression height requirements and how they have to match the stroke and rod length being used. They think they can use any 4" bore piston.
Most common is guys trying to use a 350 piston on a 327 crank, result is piston is more than 1/8" down at TDC.
The opposite scenario, 327 piston with a 350 crank, can't physically happen....the entire top of the piston would stick up out of the bore at TDC by almost 1/8"....you'd never even be able to bolt the head on.

When I run your deal through a compression calculator and leave the piston .125"+ down the bore at TDC, I get numbers like you posted, in the mid-to high 7's for compression ratio even with a 5cc dome, which is a small dome really.
No chance it hit the head if compression height is wrong for the 327 crank.

Bent rod is more likely the result of hydro locking the cylinder, either with raw gas or coolant.

If the piston is as far down as you say the compression ratio is, you have two ways to fix the issue....drop in a 350 crank, or switch to a longer set of connecting rods.
If they are stock 5.7" rods now, you would need 5.850" rods to fix the issue with the existing 3.25" stroke crank.
Eagle is the only one I know of in the sportsman I-beam price point (about $300) otherwise several companies make full-on race H-beams ($550 and up).

With 3.25" crank, 5.85" rod and piston .005" down at TDC, compression ratio is 10.3:1....327 cubic inches

With 3.48" crank, 5.7" rod and piston .005" down at TDC compression ratio is 10.95:1 ....350 cubic inches

Most piston company catalog/online listings give compression height.

The 2.055 valve size is fine, doesn't require a big cam or race parts. They will work fine even with a small cruiser cam.

 

Wow. Where did you learn this. that 327 with the piston being 1/8" down sure afirms why I buy an engine. Lots to consider. Another big mistake to me seems to be camshaft choices. Getting everything to work together is paramount to optimizing. Things like converter, and gear too. Guess all of this is why Bob Glidden was such a magician.

 

Wow. Where did you learn this.?

Just 30+ years or building and playing with small block Chevy's, from the time I was old enough to drive in 1983.
Many things learned, both successful and not. The school of hard knocks, lol.

Another big mistake to me seems to be camshaft choices. Getting everything to work together is paramount to optimizing.

Things like converter, and gear too.

Something overlooked by a great many rodders.

 

To bad its all mismatched parts, a good 327 is a a nice engine, especially the old L79 350Hp version.
Id just use the 350 block have it checked and machined and buy a 350 rotating assembly. LS's are great engines, but I wouldnt want to get involved in computers and all that BS.

 

LS's are great engines, but I wouldnt want to get involved in computers and all that BS.

you dont need a computer for an LS, you can run them with a carb and an ignition box. they also make a front cover that takes a ford dizzy (but adds length)

 

Hey all, thanks for doing some thinking for me. Obvious now, but I did my cr math wrong. And I'm pretty confident this guys engine is a a collection what was around the shop.
I am happy that he may be able to use what he has and just pick out a cam. We'll try getting it checked, do some research, get some rods, rings, gaskets and bearings.

 

As a lover of the 327, I am deeply hurt by this terrible Frankenbuild. And also by the "Just get an LS"comments.

However, like Scott says, prices to build a decent SBC are getting way out of reach -- kinda like cheeseburgers and fries. A roller cam and aluminum head update for my truck's 350, which I've been considering for a few years, has become a bridge too far for my wallet.

 

For the cost of reman on a smaller-displacement 327, you could buy three 350s. Unless he REALLY wants a 327 for some reason, this is an easy punt in my opinion. Sell it to a restoration fanatic.

 

I used a 307 crank in a 350 "010" block, so only the pistons were 327-specific, and they were no more expensive than 350 pistons. I did have to get it balanced, but I would have also done that with a 350, unless I bought a balanced assembly.

 

Lots of great comments on this here. I have run and built a few 327's (My personal favorite), from mild to extremely wild. Great little high rev engines. Done plenty of 350's, same mild to wild and still prefer the 327. Then I found the great 383 stroker.... and damn now that is fun... and built a few of these now and recently i got my 1940 Chevy Coupe that has a solid 2-bolt main that was then drilled out for splayed 4 blot billet main caps, line bored, Eagle Steel Crank with Lunati 6" Rods and pistons for a 383. This if you ask me is the best way to run a 383, 6" rods, steel crank and forged pistons for a 383. This takes away alot of the "Lugging" that was referenced previously. BUT this comes with a very large price tag, but if you get it in a car you bought.... With all that said, I have also built a few LS motors and as also previously mentioned, i will never again build a gen 1 small block. The cost is too expensive and the advances in the oiling, firing order, block design, head designs and all aluminum and the most wonderful part is how almost all if not all of the gaskets are o-ringed in some way or similar with little need for any damn messy gasket goo, and then you can carb them or Inject them. Ya, LS for me from now on.
I have a early 2000's LS 5.7/5.3 fully assembled block and brain that was given to me for 150.00 sitting on the shop floor, just waiting for a carriage to be set into.
My best suggestion is to get a book or info online on "building an LS Engine" and go that route. There are a few tricks you must know as you are doing one (the biggest pain in the arse is the pre-oiling procedure), but otherwise the rebuild kits are fairly cheap and stock they have aluminum heads already!
good luck either way you go!!!

 

...and the most wonderful part is how almost all if not all of the gaskets are o-ringed in some way or similar with little need for any damn messy gasket goo...

Yes, the LS gaskets in carriers are really nice They are light years away from Gen I gasketing. If only I were younger and had the budget for an LS. 😕

 

Start fresh, buy a new or used 350 crank, some Speedpro 345np flat top pistons or 423 dished pistons, great pistons for a rebuild, hypereutectic and fairly cheap. Delta regrind 268 duration cam ($85 bucks plus shipping) or summit 1102 or 1103 summit cam, summit cam bearings, main and rod bearings (Cheap). You already have the heads and intake. probably less than $1000 for a rebuild if you know what you are doing. This engine in a old merc, that's a heavy car. Torque is needed to get the thing moving. Torque over HP makes a much more enjoyable street car. I like simple, it works . Just my opinion.

 

We feel torque in the seat of our pants. HP is a dyno rating, and we need that on the track. At least this is what i have always been told.

If using a carb, proper tuning and sizing makes a big difference for stree use.