The name “Chevrolet” is for reference purposes only. Not affiliated with General Motors.
This is my comprehensive series of articles on obtaining the best speed & performance from your Chevrolet 1954-62 (full-pressure oil) 235 & 1954-63 261 in-line six cylinder (L6) engines (as well as the older 216 and splash-oiled 235, although in less detail).
Your “obsolete” stovebolt is capable of surprising speed & power, without loss of reliability. It’s the most complete literature you can buy to get the most from your engine. Before making any decisions about modifying (or even rebuilding) your motor, get the best help available, and do it right the first time.
This is not a re-print of the firing order, options, number of cylinders, serial numbers, casting numbers, rated power, compression ratio, &c. It contains only information that is useful and relevant (no pictures of chrome accessories).
Rather than merely summarize and repeat what you’ve already read by “California Bill” Fisher, Frank McGurk and Roger Huntington (which were written 50 years ago), my purpose is explore, explain and detail modification, fine tuning, improvements and
modernization using current parts and technology. Use it with your service manual for best results. Not an expert mechanic? You’ll still find many improvements you can do yourself with common hand tools
What about the “Chevrolet Inline Six-Cylinder Power Manual”, by Leo Santucc? It’s excellent - but contains no information about improving the stovebolt, only the very different 1962-* 194, 215, 230, 250 & 292” “Generation-3” L6 engines. Click here to see more details: .
This product will provide a good fundamental basis for those familiar with racing engine design, but without prior experience with the stovebolt for planning and constructing a serious vintage race engine for H.A.M.B., S.C.T.A., &c.
This product does not discuss 12 port aftermarket heads such as those made or marketed by Bill Fisher, Fontana, (Wayne) Horning, Howard (Johansen), (“Nick Glaviano & Son”) Nicson, (Bob) Toros, (Harry) Warner, Wayne (Horning) and Western, as these are extremely expensive collector’s items and difficult to find. For more information, click here: .
I guarantee that you’ll find information in this product you’ve never seen before, and which will help you plan and complete your project.
Consider this: if this product saves you from making even a single mistake or bad purchase, or gives you one new idea, doesn’t that make this purchase worth while? The price is a very small fraction of what you’ll invest in the motor - plan it more intelligently, and get better results.
has been a
source of performance literature since 1971. The advice and suggestions are not reprinted from other articles, magazines, or factory literature and are not available anywhere else, (although some of the data is public).
Contents so far in the draft version are 160 pages (over 135,000 words), includes the following subjects, with over 90 data tables and a sample engine modification worksheet.
How these engines differ from the similar G.M.C. 228, 236, 248, 256, 270 & 302 six-cylinder light truck engines.
How these engines differ from the more modern 1962-* Chevrolet 3rd Generation (Gen-3) 194, 215, 230, 250 & 292” L6 engines.
How much power can I realistically expect to get from my engine?
Speed equipment; aftermarket parts (both obsolete and current), cams, “split” exhaust manifolds
Siamese (shared) intake and exhaust ports: how do they affect the engine?
; how the parts function, comparison between Chevrolet and G.M.C. engines.
; design, combustion chambers, port shapes and sizes, valves, dimensions, flaws.
; what is this? How to replicate one from a common casting
Milled and filled? Ported and relieved?
; what does that mean?
Aftermarket manifolds; why are there so many types? How are they different? 2 carbs vs. 3 carbs: which is best, and why? How to modify an aftermarket intake manifold for better performance with original appearance. This section alone is 13 pages long.
Intake manifold heat?
; which is best: water heat, exhaust heat, or no heat?
Carburetors; 1 bbl. vs. 2 bbl. vs. 4 bbl.? Dual vs. triple? How large should the carburetor be, and why? This section alone is 15 pages long.
; which is best: straight or progressive? This section alone is 3 pages long.
Oil system; how it works, why it’s different from Gen-3, improvements, controlling crankcase pressure and windage (12 pages).
Modern automatic overdrive transmissions; differences between models, shift controls, torque converter stall speed selection, ratio choices
Choosing an axle ratio; based on transmission choice, engine design variables, wheel size, &c.
; what you can do yourself, including:
» Diagnosing and correcting multi-carb linkage problems (useful on V8 tri-power engines also)
» Making your own multi-carburetor intake manifold
» Planning a stroker crankshaft using Gen-3 292 L6 rods
» Alternate connecting rod choices
» What is a “hybrid” head, requirements, basic steps in planning this complex project, selecting
a donor head, critical similarities and differences (sorry, not specific instructions)
» Improved piston design
» Calculating compression distance and ratio
» Up-grading the ignition and tuning the advance curve
» Modifying the head for better breathing
» Improving the original intake and exhaust manifolds
» Making or adapting headers
» Splitting the original cast-iron exhaust manifolds
» Fabricating a cast header out of common industrial supplies
» Analyze, compare, and select a new or re-ground high-performance cam
» Correcting the rocker arm geometry for hot cams, head milling, longer valves; this section is highly technical, extensive and detailed, and will be useful to anyone interested in shaft-mounted rocker arm geometry (not stud-mount, as used in later Chevrolet L6 engines) in general, including V8 engines, such as Chrysler LA & B/RB, Ford Y & FE, Buick, Cadillac, Oldsmobile, Studebaker
» Improving the oil system, including modifying the original pump
» How to predict a safe RPM limit
» Modifying the cooling system to increase performance, including reverse-flow
; showing bore, stroke, rod length, valve sizes.
TRW Part Numbers
; lists many potentially useful obsolete numbers and applications.
Work Sheet sample
; to help you keep records and plan changes to your motor.
Many of the comments and observations will also be of use to those with other older in-line OHV pushrod engines with siamese ports, including the Buick 248, 263 & 320 OHV straight eight, Ford OHV 223 L6, &c. although no specific recommendations are made.
A book on older in-line side-valve (flathead) L6 engines with siamese ports, including Dodge & Plymouth 218 & 230, Chrysler & DeSoto 237, 251 & 265, Pontiac, Ford 226, Hudson 232, 262 & 308, Oldsmobile, Pontiac 239, Rambler 196, Studebaker, &c. will be available separately in 2017, click here for details: .
A book on the 1939-63 G.M.C. 228, 236, 248, 256, 270 & 302 L6 light truck engines will be available separately in 2017, click here for details: .
Please note: this is not a “coffee table” book, it is intended to be a research tool for those who seriously want to improve their stovebolt motors. It is not a repair manual. If your car won’t start, spark plugs foul, low oil pressure &c. my product will not help you. It does not contain information on tune-ups, or explain how to remove, disassemble, clean, rebuild or restore the engine. If you do not already have this information, do not buy this product. If your engine is stock and you’re pleased with how it runs now, this product is not going to be of much use, although you might find it interesting.
Why you may not enjoy it: it’s really long, highly technical in many places, and (if you’re an experienced engine builder) contains much information that may already be familiar to you, although I’m sure you’ll be happy to see which methods are relevant to this very unusual engine.
Shop owners and dealers: are you able to answer technical questions about the stovebolt engine? Your customers want this work done to their engines - sell them the product first, then the parts, machine work and labor. I have a modest dealer discount for volume purchases, ask before ordering.
This product will be available in 2016. Do not order, all payments will be refunded. Click here to receive notification when this product is available: .
This product is not a printed book, but a .PDF computer file on a CD (compact disc). It can be read on any desk-top, lap-top, or tablet by any computer operating system (Mac, PC), using “Acrobat Reader”. Load it into your work station at your job, and plan your project during lunch. Read it on the train, or in your doctor’s office.
PDF format offers advantages not available in print, such as:
» The text can be “zoomed” larger for easy reading.
» Topics and key words can be found with the “search” function.
» You can jump directly to areas of interest (rather than examine each page in numerical order).
» Many illustrations are in color, which would be prohibitively expensive in print format.
» Illustrations can be zoomed much larger for examination of fine detail.