267 small block chevy

Just curious- what do you have planned?


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To revise, and this is coming from strictly a frugal racing standpoint. Meaning if i come across this engine(or similar sized engines) and it's likely that i would given my current goals of keeping costs down to a minimum, i would not be driving it on the street for very long and would transfer operations to track-use only.


Headers
Remove mechanical fan, replace w/electric
Lightweight wheels and slicks----weld dragstar (or whichever one is 5 spoke) or centerline auto-drags

Low rear gear such as 4.56 or lower if possible.

Easy, although not nessesarily high, weight reductions; There's alot of obvious stuff here---i think 300lbs is not out of the question.

Then we'd really see what a 267 can do e.t. wise. The problem with the complaints regarding 305's/267's and the like is you have to consider what applications and combinations they were installed in; Most 305's and smaller were installed in heavy smog applications in cars that weighed 3000+ from the factory with stratospherically high gear ratios---like 2.56, 2.41, even 2.20! Exhaust wasn't really great either. This does not make for a good performance rig.

i'm really intrigued and fascinated by the whole budget drag concept and i think it will work.

2.14:1 was the highest I know of, used in the '79 Malibu, for one.

The problem is the bore size- or more the lack of size that keeps the valve size so limited that high RPM use is out- it just cannot breath.

Of course you can boost one- but for every dollar spent on the 267, the exact same dollar will get you more HP from any other SBC- even the ill-fated 262 IMO.

Cobalt,
I want to build a small bore chevy V-8 and the 267 is the smallest out of the box I can get, if I can find one. I have just started looking so as with most non-mainstream stuff it may take a while. I have built some small bore stuff to race with in the past and it was more like 305 block stuff, I think the best engine of the bunch was around 525hp and we turned it 7800-8200.

I have a friend who knows where a couple are in Chicago and he is trying to get them down here but no guarantees there. I plan on sticking a pretty big crank in it to get the cubes up some and still keep the engine small in comparison to many others. Bore friction is one of the major power robbing factors when you look at what steals power from an engine. That is why smal bore, small engines are usually more efficient in producing power. Sorta like F-1 and Moto-GP @ close to 4HP per cubic inch. If I can get some decent power out of the engine I might try and make an attempt to build and EMC engine out of it ( Engine Masters ).

BTW, I like your Desmo avatar, that is a really slick valvetrain system and probably one of the best there is that is 100% mechanical.

Your engine sounds like a bit of a frankenstein, not sure why you chose 400 heads but if you decide to make a change the newer truck vortecs are wayyy better. Like maybe 50 ft/# and could possibly pick up some gas mileage if you stay with small valves and camshaft. That 305 I referred to in the beginning used those heads.

Just saw your post on bore size limiting air flow...yes it does on a flow bench but there are a number of things you can do to work around that problem.
Good thing we don't race flow benches...I have had one for 25 years and they are great but they don't tell you everything. I have worked on restrictor plate stuff for about 15 years and all that applies to getting a lot of air into a little hole. One thing most folks don't understand is building negative pressure ( vacuum ) under the restriction. When you do that it is like adding positive pressure above the restriction ( blower ).

Physics don't lie it just helps out the folks out that know how to work in concert with the laws of nature.

Wha...? Frankenstein? 400 heads?? No idea whose engine you're referring to- but it ain't got nothing to do w/me, I can assure you.

It limits valve size. Physics, remember? Resonant manifold tuning, Helmholtz et al, can give a boost (that is available at several orders of magnitude) but still over a relatively narrow span "per order", so w/a small NA engine that makes big power you'd need a LOT of gears or CVT/IVT, etc. IMO this is why boost is preferable over trying to make a little mill act big by other means- unless it's a racing class/rule requirement to run such a tiny engine.

So what specifically do you want to do w/a SBC 267?

Cobalt,
As far as your engine, I misread your description on "wiki search" as the engine you were working on.

As far as the application, I am not concerned about rear gear or transmission as that is the simple stuff. My personal preference is build and engine with 500+ ft/# and stick a 2.73 in the rear with a 6 speed trans and let it eat. I have been working my way down in bore sizes on race engines as other folks have been working their way up.

Ever wonder why F-1 preferred 12 tiny cylinders to 8 big cylinders to make 3 liters??? Rules then outlawed the 12's and made everybody go to 10cyl.

Anyway, I have a couple ideas that I want to work on and I have 30 years worth of Chevy stuff and enough parts to build plenty of them. I might have to resort to a new Ford, but I don't have a pile of parts for them.

If I don't find one soon, I'll just sleeve one of the 4-bolt 305 blocks I have down to 3.5" and rock and roll with that. One of them will probably be just as good and I can use a late model hydraulic roller set up, just to blow folks minds. My GM604 Dirt Crate stuff turns 7500 with stock parts and lasts a season or two so reliability should not be a problem.

As far as valve size goes, how much air will a 2.0" intake valve flow???

How much airflow does a 400cfm SB-2 w-2.125" intake head have if you drop the bore from 4.125" to 4" to 3.5". Answer, even with shrouding they still flow a ton, and if you move the intake over a little and make it 1/8" smaller...

Combustion chamber shape, piston dish can influence airflow +/- 20%.
I have had a flow bench for 25 years now and I have seen differences in going bigger on bore, but I have also worked around the negative effects of cylider wall shrouding to get by some rules so I have a different opinion when it comes to small bores.

Oh Yea, I never said the engine would be small...I said I wanted to start with a small bore.

BTW, if you want a cheap engine for your wagon that will make 500ft/# and still get 25mpg get yourself an LS out of a van or pick-up truck from the junkyard for $500-$1000 and you will be light years ahead of anything you can build out of early stuff. You can port the heads and put a tiny cam in the thing and make crazy power. You can also buy a carb manifold from GM and a Front cover with dizzy and those are the only expensive parts. If you don't want to convert you just need to save the CPU and sensors.

If I get time that will be my 2012 project. I do have a 625hp LS sitting in the floor but it is a Dry Sump race engine complete with CPU and 4 1/2" Carbon Clutch fresh from Lingenfelter. I would like to sell it to a Vette person to help fund my Salt Flats project.

Still on the lookout for *************

I don't know why you're being so vague about your 3.5" bore project. I can assure you there are no "new" ideas and I seriously doubt anything you'll say here will suddenly make the 267 SBC the "new" 4" bore SBC. But whatever. Gotta keep em guessing I suppose.

No, actually I don't wonder why. No offence but that's kind of F1 101, the unlimited formulas have always gone to as many cylinders as can be packaged for any displacement- that's the "why" behind iconic engines like the RC166 6-cylinder 250cc Honda (see below)- which would make your 3L F1 mill a 72-cylinder affair! But what that has to do w/a small V8 might be the better question. More cylinders per displacement is one thing. Well understood, etc. A lack of displacement in a NA application where there are no rules to that effect is quite another, IMO. Maybe a mileage thing- but that is just not my personal cup o' tea.

A 3.5" bore SBC even w/a 4.25" stroke nets you just 327 cid. With a 4.5" stroke, you are STILL shy of 350 cid. There'll be much higher than usual piston speeds to contend with if it turns any serious RPM, so what is gained w/a small bore's better frictional losses gets eaten back up in ring flutter and the other probs. associated w/elevated piston speeds caused by a long stroke at high RPM. And considering you have repeatedly mentioned F1-tech, and that you seem to eschew boost I can only guess that high RPM is part of the plan. Or maybe you're gonna chain a couple of them together, who knows...

Thanks, but I have what I need AFA an engine for the wagon. What I don't have is a source locally for E85, so I'm biding my time for now to see if this changes before I finalize anything. I'd like to do a simple intercooled turbo SBC 355. Production parts, including Vortec heads, carbed, low-tech. Easy 750-plus HP that will not cost a fortune, but this depends on fuel that is not currently available cost-effectively.

Anyway, good luck w/the 267 block quest. I believe you'd be better off sleeving a 305, but then that's a costly affair if a stock bore 267 is enough for what you want to do.


ROD/PISTON, 6-CYLINDER RC166 250cc HONDA

I am keeping a low profile on the project because I want to do the R&D before I announce the results.

Piston speed is exactly what I am looking for as well as using a 5" rod in it to de-bunk that BS about short rods. I used to run ARCA qualifiers@10,200 to 10,500 before they put rev chips on us. We ran. 030" rings with spacers and pretty good vacuum with Weiss pumps plus a lot of work on bore and ring finish to get the engines to go 250 miles.

Even if I do get the 267 blocks they will be getting 8 sleeves to accomplish what I want.

You might want to do some Dyno testing with E85 before you get too far on your engine project. Store bought E85 is junk. I have 5 drums of it at my shop that I test with for dirt Carbs and I have 2 stations within 10 miles of my house in Sugar Hill and both of them vary+ /- 5% on E content and the gas they use is putrid stuff.

I guess it might be worthwhile if it was way cheap but it is only 10c less a gallon.

When you say economy how much do you estimate your 750hp engine to cost?

There are ways to determine how much alky is contained in a volume of fuel. I wrote a brief Wiki on this in 2009.

As for the cost of E85 being "high", it's all relative. Price any other high performance fuel w/the detonation resistance under boost of E85 and then add the convenience of topping up at a filling station as opposed to carting and storing drums of fuel and for me it becomes a no-brainer.

Rod length is much ado about nothing IMO.

MY cost for my engine and someone else's cost will be different, as I have a knack for finding deals, working trades, bartering, etc. for what I need. I'd expect to have maybe $1500 out of pocket by the time I fired it up.

How do you determine how much water is in your E85?

Good luck on them local fill-up stations. With govt droppin many of the support programs you wont see many new alky pumps added in the near future.

Pretty awesome on the engine budget I would have that much in the heads alone and I have pallets of heads to valves and retainers springs etc.

I did build an ally 400 about 15 years ago and put it in my suburban.She got 20mpg around town and 25mpg on the freeway@ 60mph. Was sponsored by VP on fuel and let the GOV pay for the program on a fuel research grant.

I am thinking about swapping my 94 GEO METRO over to ally and let Obama pay for some more R&D. It already gets 45mpg on gas so it should not be to hard to get it to 60 mpg.

If it was a concern for me (which it isn't presently) I would use a simple density test. I saw "simple", it will require some work, but the basics are well understood.

AFA engine cost, I'm obviously not figuring my own labor into it. If I were to do this for a customer the cost would be significantly higher.

i got a 83 camero with a 267 he put it together put a cam and a 4bbl i`ve never had it dino but he say`s it has as much hp as cid i can say it is pretty strong.i can say that from 0 to 75 it will beat a stock sang

This thread is old. However, I'd think you should look at the casting numbers on the block to make sure it's a 267 instead of going by what you were told. You really can't hot rod a 267. The bore is so tiny it kills the engines potential to breathe. When you say "Stock stang" do you mean one with a 6 cylinder as a 267 on its best day wouldn't have a chance against a 302 or a 4.6 liter on there worst days.

Iron heads crack long before they worp

I think the small bore thing and killing airflow has been way over played...You might want to check the bore sizes on the new Fords and LS's as they are getting smaller with increases in stroke to make additional displacement.

As you will see in the future increases in engine efficiency will come from smaller displacement, reduced bore size, increased stroke...the reduction in friction losses is pretty big and with new ways of measuring these affects you will see a lot of changes in the future.

It is very easy to put small valves in a SBC head and make almost the same flow as a larger valved head as long as the port design is proper. Putting a 1.84 valve in a 2.02 head can show significant gains if the valve job is modified and the camshaft is juggled around some. We have seen 305" SBC engines with vortec small valve heads on them hit 500hp. Not a huge number but considering what it is a 350 would have to hit 560hp for the same HP/" ratio with the same heads.