TheAMCForum.com Homepage
Forum Home Forum Home > The Garage > AMC 6 Cylinder Engine Repair and Modifications
  New Posts New Posts RSS Feed - 199 performance build
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Click for TheAMCForum Rules / Click for PDF version of Forum Rules
Your donations help keep this valuable resource free and growing. Thank you.

199 performance build

 Post Reply Post Reply Page  <1 2345>
Author
Message
amc67rogue View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Nov/05/2008
Location: Phx. AZ.
Status: Offline
Points: 1578
Post Options Post Options   Thanks (0) Thanks(0)   Quote amc67rogue Quote  Post ReplyReply Direct Link To This Post Posted: Apr/08/2013 at 3:48pm
The 287 has the same bore and a .930 pin but the compression height is even taller than the buick pistons .
Keith Coggins 67Rogue X code
Back to Top
HHaase View Drop Down
AMC Apprentice
AMC Apprentice


Joined: Oct/17/2012
Location: South Dakota
Status: Offline
Points: 100
Post Options Post Options   Thanks (0) Thanks(0)   Quote HHaase Quote  Post ReplyReply Direct Link To This Post Posted: Apr/09/2013 at 1:09pm
I think I looked at the 287 pistons, and the compression height was just too much.

Hearing back from a couple piston folks, and the big question I need to answer is head gasket thickness and head gasket bore size.  Not finding squat on this information yet.
Back to Top
farna View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar
Moderator Lost Dealership Project

Joined: Jul/08/2007
Location: South Carolina
Status: Offline
Points: 19612
Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Apr/09/2013 at 1:12pm
Compressed gasket thickness will be around 0.042". That's the figure most often seen on the 4.0L sites anyway. 
Frank Swygert
Back to Top
HHaase View Drop Down
AMC Apprentice
AMC Apprentice


Joined: Oct/17/2012
Location: South Dakota
Status: Offline
Points: 100
Post Options Post Options   Thanks (0) Thanks(0)   Quote HHaase Quote  Post ReplyReply Direct Link To This Post Posted: Apr/09/2013 at 2:25pm
Pardon me while I smack my head.  Forgot I was going to put a 4.0 head on this, so forgot I needed the 4.0 head gasket measurements.

I blame this snowstorm.

-Hans
Back to Top
Slate View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Feb/28/2012
Location: Airyzona
Status: Offline
Points: 2783
Post Options Post Options   Thanks (0) Thanks(0)   Quote Slate Quote  Post ReplyReply Direct Link To This Post Posted: Apr/10/2013 at 9:58pm
If you have to up the pin size on the rods looks taoffset grinding the pin end if there is enough mass at that end to do it. That increases the rod length. You have a small amount of room to stroke the crank too  cheap- about $175.  You have a little more than 100cc's wiggle room.  After crunching the numbers decking amounts would come down and other piston options with less rocking motion come up.
 
T S
Back to Top
uncljohn View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Jan/03/2013
Location: Peoria AZ
Status: Offline
Points: 5394
Post Options Post Options   Thanks (0) Thanks(0)   Quote uncljohn Quote  Post ReplyReply Direct Link To This Post Posted: Apr/12/2013 at 10:28pm
The explanation on connecting rod length on page one leaves me a little confused about the term "Effective stroke"

Rod length has nothing to do with stroke At least as I have read and understand theory.
Rod's connect the crank shaft which is the part of the engine that determines what the stroke is to the piston which moves up and down.
A long rod will push the piston further up but it also starts further up, a short rod on the other hand does not push the piston as far but then again it does not start as far up. The stroke is the same on both examples. As the 199 block is of the same family as the 232 and the 258 with out looking up any dimensional variation between the two and the need to bolt up a particular engine to a particular transmission. This being a block built from 1972 on to a transmission and bell housing combination it becomes a matter of how high the piston will rise when pushed by a stroke of 3 inches of the 199 vs 3.5 inches of the 232.
The stroke is a constant no matter what connecting rod is used.
The question is where is the piston going to stop at the end of a 3 inch stroke and that will be a function of how long the rod is.
Remember it not only is going to stop higher, but it also is going to start higher. It is only going to move 3 inches no matter what.
My TSM indicates that the 232 crank bearing measurements are going to the be same as the 199 so the assumption is that a 1973 232 which bolts to all the later transmissions will also accept a 199 crank with out a problem. As the bore for both engines are the same, then the 199 rod and piston should also work. Leaving the only unknown as to how great a space is left above the piston known as deck height to the top of the block and the size of the combustion chamber.  And if needed can the amount of the material at the top of the block be milled off safely.
My answer is I don't know but it is one that is a straight forward thing to determine. So I guess I am not sure I see a problem.
Yes the 258 in the middle 70's was a taller block, but the 258 was derived late too.  So a 72ish 232 block it seem to me would work for what you want to do. Unless of course I am missing something here. All wheel drive SX4 might be a problem but 2 wheel drive Gremlins and Spirits would not or anything similar. I have an early 232,  I think it is a 73 and there are mounting hole variations between it and a later 258 for a lot of accessories. But I can bolt up a bell housing for a 5 speed and install a Merkur 5speed I have on it if I wanted to.

I guess if it boils down to what block can be used as being compatible to bolting up to a 4 wheel or all wheel drive transmission if jounal sizes are the same all the way up the line the next question is how much combustion room do you have left and what can be done about it.
Decking a block and milling a head is Standard operating procedures in engine building. Before I would worry about exotic solutions, I think I would worry about the stock parts first and what you can get with them and how to tune them for maximum performance.
You ought to be able to turn a short stroke engine pretty tight. Reliably. I can reliably turn my 258, a typical long stroke cat to 5000 pm.  I don't have enough cam to look at higher rpms.  But my 232 which will be build later on should be an easy 6500 rpm engine. And develop fair usable hp with 9:1 compression.




Edited by uncljohn - Apr/12/2013 at 10:51pm
70 390 5spd Donohue
74 Hornet In restoration
76 Hornet, 5.7L Mercury Marine Power
80 Fuel Injected I6 Spirit
74 232 I-6, 4bbl, 270HL Isky Cam
Back to Top
farna View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar
Moderator Lost Dealership Project

Joined: Jul/08/2007
Location: South Carolina
Status: Offline
Points: 19612
Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Apr/13/2013 at 7:33am
64-70 six blocks are the "short deck" blocks. 71-06 are all "tall deck" -- I seem to recall them being 1/8" taller than the short ones, might be 1/4".

The monkey wrench in this is that the 71 tall deck blocks used the old small six bell housing pattern on the block, the 72-06 blocks use the larger AMC V-8 pattern. That comes in handy is wanting to use a 258 in an older car, but you have to have that 71 only block.

The accessory mounts changed for 1974. The bolt pattern for the timing cover remained the same, but the sizes of some of the bolts changed so they could handle carrying accessory brackets. You can put a later cover on an earlier block, but have to use washers under some of the bolts to cover the larger holes and you have to use the old style accessory mounts. It's not pretty, but I've seen it done. To go the other way around would require drilling and tapping some of the holes larger. I don't know for sure if there is enough "meat" in the bolt hole areas of the older block to do this, but I would suspect so.

Even the 258s were turned up to 6500 rpm in race trim. I wouldn't build any of the sixes to turn over 5000 unless it's a mostly strip car. They just aren't as good at high rpm power. Build to take advantage of the sixes great low speed torque instead and you'll be happier with a street car. If you want to run high speeds you will likely be happier with a V-8, though a short stroke six turning tight would be great in a light car. 
Frank Swygert
Back to Top
uncljohn View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Jan/03/2013
Location: Peoria AZ
Status: Offline
Points: 5394
Post Options Post Options   Thanks (0) Thanks(0)   Quote uncljohn Quote  Post ReplyReply Direct Link To This Post Posted: Apr/13/2013 at 8:21am
An engine that is rated at about 190 ft pounds of torque at around 1800 or so rpm does not come under the heading of great.  At least not in my book anyway.
If the idea is to build a race motor  than it is by definition one that will turn higher rpm's which is a by-product of building a RACE motor.
And as one way to define an engine is a positive displacement air pump one way to get it to develop more HP  is to get it to pump more air.  And the standard method of doing that is to give the capability of turning more rpm's.
A formula commonly used to develop a motor or engine for any form of racing.
And that is not dependent on the number of cylinders or the configuration of them. It is however partially dependent on the length of the stroke used in any particular motor. A physically long stroke motor is not really very happy at higher rpm's.  However many have lived there for long periods of time.  A short stroke motor is happier. One with a 3 inch stroke can mechanically be turned at higher rpm's with fewer inherent problems.  As compared to say one with a 3.5 inch stroke or a 3.9 inch stroke.
An 401 cu in AMC engine has a factory stroke of about 3.7 inches.  And the same rules apply to it.
Just because it can be turned that tight or tight by what ever definition is used, does not mean it has to be driven there at a constant speed while driving. It means the capability is there.
American inline six cylinder engines by in large are throw back in concept engines to the 1930's when high compression was 6:1, speed limits were 45 mph and it was rarely expected to see one travel at a mile a minute. The carburetors were tiny and still are and they were under-cammed and what was called under square with bore size generally smaller than stroke was long to build a long narrow engine that fit under long narrow hoods.  And as the tooling already existed to make engine of that size as the modern engine developed as an option to them, they stayed in production as an inexpensive base engine that worked sort of an people bought.  Jaguar, BMW, Mercedes Benz, and many other racing engines were developed using the I6 engine which is an indication only that configuration does not make an engine but how the configuration is applied. Even Jeep had an overhead cam I-6 that became notorious as a high performance racing engine in another country that did not have a pre-concieved notion that it could not be done.
Do not let the old wives tale that an inline I-6 is a great torque motor thus can not be built into a great racing motor deter you from doing so. In the first place it is a lousy torque motor.
In the second? It makes a great racing motor too.

To me, the idea of building a modern equivalent of something that is built to a very small displacement sounds like a challenge that might be kind of fun using an AMC based parts box.  I am not so sure that a 4.0 head is the best choice for it though taking an overall look at the objectives. Early 232's had a rocker shaft rather than the stud mounted rockers. Using that head and pocket porting it makes a certain amount of sense as the platform to mount the rockers on, a shaft is a stable platform at higher rpm's.
Just a though anyway, but one I am going to utilize if my 232 has a shaft based valve system.  I don't know that it does, but when I get around to looking if it does I am going to be satisfied that it has one and just go ahead and use it. It is old enough that it could be. It is like many projects I have a round-tuit project. I need to finish 2 others first.






Edited by uncljohn - Apr/13/2013 at 8:38am
70 390 5spd Donohue
74 Hornet In restoration
76 Hornet, 5.7L Mercury Marine Power
80 Fuel Injected I6 Spirit
74 232 I-6, 4bbl, 270HL Isky Cam
Back to Top
farna View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar
Moderator Lost Dealership Project

Joined: Jul/08/2007
Location: South Carolina
Status: Offline
Points: 19612
Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Apr/13/2013 at 8:35am
The max amount of torque an engine produces is directly related to size (cubic inches). The sixes don't put out more torque than a larger engine. The max torque rating on the one mentioned is 190 ft/lbs, but the torque curve is rather flat before and after. An in-line six builds torque quickly then holds a relatively flat curve for a long period (of course this is affected by cam choice). That same six probably produces 140-150 ft/lbs at 1000-1200 rpm, not much over idle speed, then ramps up to 190@1800, and tapers off to the 140-150 range at around 4000 before falling flat (again, due to cam). That's great for a street car.

Almost any engine can be made to run with the right mods. I'm not saying it can't be built as a high rpm race motor, I know it can. I was just pointing out that it's main forte is low rpm torque, and it can be built to take advantage of this AND perform with the right trans and rear axle ratio (a five speed and mid 3 gears usually does the trick).
Frank Swygert
Back to Top
uncljohn View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Jan/03/2013
Location: Peoria AZ
Status: Offline
Points: 5394
Post Options Post Options   Thanks (0) Thanks(0)   Quote uncljohn Quote  Post ReplyReply Direct Link To This Post Posted: Apr/13/2013 at 8:58am
Originally posted by farna farna wrote:

The max amount of torque an engine produces is directly related to size (cubic inches). The sixes don't put out more torque than a larger engine. The max torque rating on the one mentioned is 190 ft/lbs, but the torque curve is rather flat before and after. An in-line six builds torque quickly then holds a relatively flat curve for a long period (of course this is affected by cam choice). That same six probably produces 140-150 ft/lbs at 1000-1200 rpm, not much over idle speed, then ramps up to 190@1800, and tapers off to the 140-150 range at around 4000 before falling flat (again, due to cam). That's great for a street car.

Almost any engine can be made to run with the right mods. I'm not saying it can't be built as a high rpm race motor, I know it can. I was just pointing out that it's main forte is low rpm torque, and it can be built to take advantage of this AND perform with the right trans and rear axle ratio (a five speed and mid 3 gears usually does the trick).


The point though is that is a function of two things. Gross under carburetion, a carburetor that when the numbers are run is out of it's operating window at some where around 3500 rpm AND a cam shaft designed to fall flat on it's face.  A basic 1930's era performance window.

The first thing an engine that is oriented to a performance application gets rid of and replaces them with a carburetor that is suited to run at higher rpms efficiently and a cam shaft that will let it happen.  Cylinder configuration has nothing at all to do with that.

The rear wheel dyno. curves curves graphed from 2700 rpm to 4000 rpm and limited by the about 190 cfm carburetor that at the time was on my 258 cu in engine show 170 ft lb of torque at 2700 rpm and 100 ft lb of torque at 4000 rpm and anything but flat on the torque curves but a flat hp curve from about 3000 rpm to 3700 rpm with a peak at  3300 rpm where ran out of carburetor.  And all of that due to two things, the choice of cam, a mild street cam and the factory stock carburetor which was limiting things by being too small.
Eliminating the restriction of the carburetor by installing a fuel delivery system with a higher CFM rating moved the operating range of the engine up and easy 1500 rpm yet as still drivable as a street car with civil manners using a final drive of 2.53:1 which gave a gearing of about 32 mph/1000 rpm which says it would cruise happily at 2000 rpm all day long at 62 mph or 3000 rpm all day long at 93 mph.  Despite a significant increase in RPM Capability the need to run it there was not required.  It pulled fine at the lower rpm. It just did it faster because of the increased power band.
They make a fine race engine when treated as one.


70 390 5spd Donohue
74 Hornet In restoration
76 Hornet, 5.7L Mercury Marine Power
80 Fuel Injected I6 Spirit
74 232 I-6, 4bbl, 270HL Isky Cam
Back to Top
 Post Reply Post Reply Page  <1 2345>
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.03
Copyright ©2001-2019 Web Wiz Ltd.

This page was generated in 0.109 seconds.
All content of this site Copyright © 2018 TheAMCForum unless otherwise noted, all rights reserved.
PROBLEMS LOGGING IN or REGISTERING:
If you have problems logging in or registering, then please contact a Moderator or