Building the 267 ?

[DEVILSorchard]

I'm aware building a traditional NA 267 is a waste of effort considering the easy of bolting in a 350 but what about turboing it?

Ive been building import turbo engines for years and always wanted to play around with a blow through V8 turbo set up. The first problem I can see is any decent sized turbo strapped on a V8 is going to be capable of make insane power levels and need a seriously built engine to take it. I'm not looking for insane power levels just a fun street cruiser this is where the 267 comes in.

I have a set of 6.2" manley aluminum rods that Id picked up for a 2.3 ford engine years back thinking they where 5.7" for a turbo build. With the 267 3.5" bore block, 283 3.00" stroke crank and these long rods It should be around 3.8l but rev happy. My thinking is 305 heads to give it some flow and drop the compression ratio, aftermarket manifold and a 300-500ish cfm carb in a blowbox it shouldn't be much of a torque monster but I could push some decent PSI and rev it high to make it somewhat fun and hopefully not a ticking timebomb. Any thoughts on this setup, my power goals wouldn't be anything over 300whp targeting around the 250whp level. I know with a 350 I could use forged parts and it would probably be easier to build and capable of a ton more but I'm really trying to keep this car at conservative power levels and keep it a v8.

 

[DRIVEN]

Let me start off by say that I, personally, love the oddball builds. With that said, here are some points to consider if you haven't already.
-The 283 is a small journal crank that will require spacer bearings to install. They used to be available but I haven't checked lately.
-Your expensive rods may not be compatible with the crank either. Are they SBC or 2.3?
-Custom pistons are probably a given.
-Balancing will be necessary and could get expensive.
-The 267's dinky bore really shrouds valves in any head you decide to use.
-The combination you are proposing might necessitate a manual transmission and deep gears to be streetable.

If you were to say, "I want to toss my 267 and drop in a 350", I'd think that makes good financial sense. If you were to say, "I want to force-feed my 267 and see what happens", I'd think that sounds really fun. What you are proposing is a completely custom (expensive) build that won't likely make a ton of power. A high winding small displacement turbo build sounds really interesting and I kinda hope you go through with it. I say do it -- just cuz. I think your power goals are certainly achievable but many might argue that you're doing it the hard way.

 

[mac61891]

I agree with the previous comments. The odd motors are incredibly interesting. I was just thinking this morning that 305's and 307's are considered boat anchers by main stream, but what if someone really wanted to play around with one and make decent power, just to be different. I enjoy different.

 

[Blake442]

Couple thoughts...

Part 1 where I try and talk you out of it...
A bone-stock 350 will make your goal of 250 hp, and with your choice of cam should have no trouble hitting 300 hp.
You don't mention whether you have a 200M or TH350 trans... The TH350 can handle it, the metric 200 won't.
A TH350 or if you go with a 200-4R for the overdrive should net you a nice cruiser that's fun to drive and knocks down about 15-20 mpg.

Part 2 is where I'll encourage your creativity...
I admire your ambition, though I think you're leaning into it a bit much.
Custom rods, pistons and crank? Don't waste your money. The simpler the better... (and cheaper) Modifying all that sh*t will add up fast unless you're a machinist and can do it yourself.
Use the stock 267 long block. At 8.5:1 compression (at the most), the stock bottom end is already well suited for boost and the valves will start floating before you hit enough rpm to hurt anything.
If you really wanted to pull it apart fresh piston rings and maybe an ARP bolt kit for the rotating assembly wouldn't hurt.
An off-brand aluminum intake and a Quadrajet off a carb'd draw-thru turbo Buick V6 would be all that I would buy for it.
Flip a cheap set of shorty headers and you could potentially have a fun little ride for pretty cheap...

Just my $.02... At the end of the day there's only one way to find out!

 

[DEVILSorchard]

Oh wow I wasn't entirely sure this thread would get any positive encouragement. I'm really glad there's some interest I didn't want to go this lonely path into building the 267 alone if I do decide on this route.

These rods are 327 2.00 journal rods I already have. 5.7" SBC rods do fit 2.3 fords but it puts the wrist pin into the oil ring land so being 6.2 they ended up being useless and sat on the shelf for the last decade. Id only threw that info in there so you guys wouldn't get the idea this is my first engine build of this magnitude.

Id considered the large journal, small journal issue Ive done some searching on that and there is still massively over sized bearings to fill the gap although I'm not sure how I feel about the crank being supported on a thick bed of babbit. We had this issue on the 2.3 fords as well and what we did was use small journal caps with a spacer on the block side and a standard bearing. I haven't found any info on that remedy yet but a large journal 327 3.10" crank is also an option.

I had considered the 3.5 bore would shroud the 305 valves and read about some guys chamfering the cylinder walls to let it breath. I'm not big on that idea but leaving it alone as long as there's no contact would help limit the power this thing could produce. I know that's a funny statement to make but my experience dealing with any large displacement turbo engines (2.6L skyline RB26, 3.0L 2JZ supra) and a lot of flow is its way to easy to make insane power numbers that the engine has no chance of supporting without a ton of investment. My approach is to find that balance of letting some parts remain a restriction and investing in a few to make it work together like cast crank and custom pistons. One of my original ideas was a destroked 350 but we're still talking around 5.0L, way higher flowing heads and intake. That would be way to easy to make way too much power and need a serious investment in the motor and not very streetable.

The GN 3.8 is exactly what I should be using for this target power / investment but the 267 just seemed like a neat option to satisfy my oddball engine curiosities. It would also be similar to a Ferrari or Maserati engine minus the flat plain crank, its hard to deny thats been working for the Italians and I could give it a cool name like Maserati's biturbo quadraport maybe the una turbo octaplenum 🙂





I'm heading to the wreckers atm Thanks for some food for thought on this idea. I will have to do some digging while I'm there and see what concoctions I can brew up around this idea.

 

[pencero]

I like the 267 v8 and I'm one of the few. One of the first Cutlasses I ever witnessed burning up a block was rocking a fresh built 267. I say go hard and who cares what a hater thinks. It can be done, although I suspect you could skip all the internal work save thousands of dollars and perhaps advancements in efi / tbi or a turbo would be a better use of your money. Don't throw your money in a trash can and set it on fire. Like members w/ more exp than me just said - the 350 makes the ammount of power you can expect to get from modding the 4.3 STOCK so watch your wallet. When you hit the top of what your displacement can do just remember the hundreds of dollars you are spending after that only will gain you fractions of a second in the quarter mile so just know when to call it a day. Don't forget it's a cool motor and it can sound a lot meaner than the punch it really packs but it will never be a strip motor it's still just a good motor for a cruiser - so go with a cam that packs all the punch midrange and not an absurd lopey cam that ruins that mean v8 sound nor a cam that puts all the peak power at the top of your range or you'll have a car thats slow to 30 so just aim somewhere in the middle and you'll have a car thats fun to drive but not absurd. Mileage should be your focal point. Like already was said the 350 can do everything you can do with the 4.3 and more so the only thing you should focus on is getting those extra few mpg you deserve or else the project doesn't really justify itself. The 350 in my 79MC got 21mpg with a 650dp holley on top - bored out. That should be the lowest highway mileage as your goal. If you don't come up with more than 20mpg you wasted money somehow. Theres no reason with the advancements in technology you shouldn't be able to get the same or better mileage from this lower displacement motor so don't forget that. even if you put the motor on an expensive ECM it will pay for itself by paying you back gas mileage in 3-4 years time easily so don't be cheap!

 

[DEVILSorchard]

Gas mileage on this car isn't really a consideration in the least but I do get exactly what your getting at. This cutlass is a spare vehicle I don't really intend on driving much, more of a restoration and tinkering project

After a day in the wreckers I can say with confidence that the 305 heads are not a good choice for a 267. Its rather apparent when you pull them off that the small bore size was an afterthought and the valves are not appropriately located for such a small bore, the smaller valves where most likely a way of making this engine work rather than an attempt at boosting fuel economy. They will bolt up fine without interference with the block but valve reliefs on the piston would definitely be needed to keep this from being an interference engine or to use a larger than stock cam profile. I couldn't see any reason a large lumpy cam wouldn't work with the 267 heads, it looks like that would be a more effective approach to making this breath better than a head swap unfortunately.

With a head swap the long rod combo will also need custom pistons. Dropping from the 3.48 crank to a 3.00 crank and adding .50" in rod length I was hoping would work with a compressed gasket thickness of about .065 or so. The piston and valve will most likely try to occupy the same space a few degrees past TDC keeping the 267 heads on with a decent cam and same head gasket may work but its probably the same scenario.

Ultimately I think this project is a bust the way I was hoping, The best I could hope for would be to drop in a forged 3.48" crank and forged 5.7 rods and run the stock pistons or have some forged pistons custom built with a dished crown and high lift cam. With a turbo build Id be better off keeping a short duration with minimal overlap and some really heavy valve springs. I'm sure I could still net some decent results with enough boost but its going to be a torquey low revving engine and not at all the power curve I wanted.





I did grab an intake off a 305, Qjet and air filter box off a half ton and may grab a 305 cam this weekend and see if I can perk this engine up for the time being. Carbs are pretty well foreign objects to me, can I just bolt this all up and run it or will this require some form of tuning? I looked everywhere and theres no ECU or USB plug for my laptop, how did so many people deal with such a primitive device for so long.

 

[DRIVEN]

Let me run this by you...The L99 (AKA baby LT1) was 4.3L and similar bore/stroke to the 267. It also had the benefit of longer rods, better flowing heads and obviously EFI -- which is more up your alley. I would think that it would make a pretty good foundation for a small displacement turbo build without custom parts and machining. Probably a cam swap, set of injectors, and a tune would really wake one up. At one point these were pretty much throwaway engines but lately they seem to be getting scarce.

 

[pencero]

Don't you mean the 4.3 L33 I think it's called? I thought the L99 was a 5.7 that came after? Either way a guy is trying to basically throw a 4.3 v8 at me a few blocks away. I was thinking of checking it out. It runs but the Caprice is kind of a dud and has a smashed bumper up front etc.

 

[DRIVEN]

No, L99 is what I meant. Found in '94-'96 Caprice.