Trying to learn about the GM 90 degree V6's

[tyoneal]

Hello:

I'm trying to find out about the Racing versions of the Chevy 90 degree V6 Engines.

Can someone shed some light on potential power output? (With Turbo, pump gas)

A good engine builder for them?

What they are normally used for and how they perform?

I have googled myself crazy and I have just not been successful learning anything tangible about them.

Here is the Block and other parts I have found for them.

http://www.gmpartsdirect.com/results...ges=1&pkgid=97

http://www.gmpartsdirect.com/perform...CATID=273.html

http://www.gmpartsdirect.com/perform...CATID=304.html

http://www.gmpartsdirect.com/perform...CATID=274.html

Looks like they would make a killer foundation for a Track/Street car, and would be something different.

Was thinking about putting one in my 1st Gen Camaro as they are really light, would help with front to back weight ratio, without setting a V8 back into the dash 6 inches, and it would free up room around the front suspension and steering components.

Thoughts?

Thanks a million for any help.

Ty

[ddavidv]

Since I'm GM stupid, which engines fall under the 90 degree moniker? Is that the 2.8/3.1/4.3 family, or something else?

[Larry]

As far as now old school V6 goes:

4.3 is 90*. Think 350 with two end cylinders lopped off. Similar to Chevy 3.8 (229 ci...not to be confused with Buick 231 ci 3.8) - 305 V8 less two holes.

2.8/3.1/3.4 is 60*. This one has an interesting evolution. Started out as a weeny 2.8 pushrod and later became a four cam 4 valve 3.4.

Since I guess GM wanted to minimize retooling costs, it has a few curious oddities:

The camshaft is now called a midshaft or something like that. Picture a camshaft with no lobes. Only reason it's there is to drive the oil pump off the rear main. That's the "fifth camshaft".

Where the distributor used to be is now an aluminum plug with an inside guide for the oil pump shaft still driven by the gear on the cam.

Timing gears - really aren't...in the conventional sense. No timing marks, so it doesn't matter which way you install the gears and chain.

And of course, since it is a four cam motor, it also has a timing belt in addition to the "timing" chain.

[Don Hann]

You're talking about the "W" code 4.3?

They used these in the Syclone, Typhoon, Sonoma GT. They used them in the S-10SS as well as a number of "lesser" S-10 type vehicles but only the Sy/Ty and SOGT seem to have the following. The other guys tend to just drive them into the ground and get another vehicle.

I'd think that you would want information from the SOGT owners (like me) but who have rebuilt their engines and not gone to the turbo setup from the Sy/Ty stuff.

You might try www.syty.net. They aren't quite as tech oriented as corner carvers but that's pretty rare. I did some searching around and did find at least a few threads where someone was building/had built a 4.3 engine.

It looks like the block you are talking about is very similar to this one and if you can find someone at Syty who knows where to go... Sorry I don't myself.

I plan on doing one myself as I've always really like the engine.

If you're talking about a different 4.3 block then please disregard.

[jwvess00]

The Buick 3.8 / 4.1 V6 is a 90 degree 6, but it is not the same as the Chevrolet 90 degree V6. Since your links are about the Chevy engine, I'll speak to that but I thought I'd mention the Buick engines since they're very popular in turbo trim (think GN / GNX / T-Type Regal) and have an aftermarket following.

When you're digging for parts, don't forget that the Chevrolet 4.3V6 was (is?) used in marine applications, which opens up the available GM parts that were not used in automotive applications.

The Chevrolet V6/90 started out in two sizes, 200cid V6 and 229cid, in various cars (Monte Carlo, Malibu, etc.) GM fooled around with two different odd-fire cranks in those engines before introducing the even-fire 4.3V6 in the Astro van in '85. '85 was the only year the 4.3 was fitted with a carubretor (a Quadrajet). After that, it was either a TBI engine (VIN Z) or a port-injected engine (VIN W).

Forget the 200 and the 229, as their heads are junk. The 4.3 is your best bet for availability (used in '85-'88 G-body cars, Caprice from '85-'90 or so, S-series trucks and SUVs from '88 on). This engine was used as the base Chevrolet V6 in a lot of cars in the mid-80s, but mainly as a light truck engine.

It can use a lot of SBC parts that aren't cylinder count specific (i.e. pistons, rings, rocker arms with some exceptions, etc.). The big exception here is the rods, as the 4.3 has its own rod -- SBC rods won't fit.

The turbo 4.3 was only in production for the Syclone and Typhoon, and there just aren't many of these. Factory output was rated at 280HP. Going from memory, the TBI 4.3 was 165HP, the VIN W ('92-'95 with CPI) was 205HP, and the VIN W ('96+, CSFI) was 200HP.

The best factory heads are the VIN W-engine Vortec heads.

GM used two port injection systems, and for a turbo engine you'll want a port injection intake. GM TBI systems don't like boost without a lot of work since there is a reputation of leaking boost. Turbo City may be able to help with that, if you want to go that route.

The VIN W engines have both a cam and a balance shaft, which makes them smoother at the expense of a bit of power to spin the balance shaft. I don't know anyone that has removed it, so I don't know if that affects anything (i.e. oiling system, etc.)

The first port injection system ('92-'95) is Central Port Injection, or CPI. It uses a central injector to feed a poppet valve at each port via plastic tubing. It is picky about fuel pressure (low == very bad) and the regulator is known to fail and leak fuel into the intake. You know this has happened when it runs pig-rich and the intake is very clean inside.

The '96+ has Central Sequential Fuel Injection. This system replaces the central injector with six central injectors, and keeps the poppet valve setup. GM has a kit to replace this bad idea with regular injectors. The poppet system is supposed to help improve hot starts, but I've never had a port-injected GM car that had problems with that. It seems like they were solving a non-problem to me.

The stock CSFI intake is nothing great. There are many that have modified Edelbrock intakes for port injectors. I've also seen cut-down Holley Stealth Ram intakes, and even a cut-down Ramjet intake. All of that is custom work, though.

The '96+ engines also have a unique ignition system. The distributor is just that -- it distributes spark, and that's it. It has a cam position sensor used to sync the PCM for the sequential injection, but it is not used to fire the plugs. There is a crank position sensor in the timing cover used to fire the ignition module, which is external to the distributor mounted on a bracket next to the coil. Why GM didn't just go with DIS is beyond me.

The '96+ PCMs are supported by editors like HP Tuners and LS1Edit, which should help.

Two forums that have lots of 4.3 owners that build them:
http://forums.s-series.org/
http://s-seriesforum.com/ -- this one requires registration to view posts.

[Astrochimp]

If you want info on the (newer) Buick 3.8, I can post some and link to much more and parts.

The supercharged engine was not used in RWD in the states, but will bolt up to the F-body autos, and the PCM will control it. Re-programmers are avalible that will let you change any/everything.

The supercharger /MAF location is set up for FWD, but Aussi parts ($$) relocate it, or its easy to fabricate a solution. Lot of turbo kits around, and supercharger swaps kits/info. Pistons, cams, etc also.

Used engines are cheap- I paid $650 for a 40,000 mile complete w s/c. Blocks are strong, w 4 cross bolt mains.

I got the spare engine because it was as cheap a used S/C at the time- local yards only sell them complete and I just needed a snout- my OE engine has 200,000 miles, 230hp 340tq at the wheels with 3 easy bolt ons @ 35,000 miles. Still got 27 MPG at wifes DD for 10 years.

David

[Don Hann]

http://www.s10forum.com/forum/f107/t...3-info-131868/

http://www.s10forum.com/forum/f107/p...er-faq-114235/

[tyoneal]

Originally Posted by tyoneal

Hello:

I'm trying to find out about the Racing versions of the Chevy 90 degree V6 Engines.

Can someone shed some light on potential power output? (With Turbo, pump gas)

A good engine builder for them?

What they are normally used for and how they perform?

I have googled myself crazy and I have just not been successful learning anything tangible about them.

Here is the Block and other parts I have found for them.

http://www.gmpartsdirect.com/results...ges=1&pkgid=97

http://www.gmpartsdirect.com/perform...CATID=273.html

http://www.gmpartsdirect.com/perform...CATID=304.html

http://www.gmpartsdirect.com/perform...CATID=274.html

Looks like they would make a killer foundation for a Track/Street car, and would be something different.

Was thinking about putting one in my 1st Gen Camaro as they are really light, would help with front to back weight ratio, without setting a V8 back into the dash 6 inches, and it would free up room around the front suspension and steering components.

Thoughts?

Thanks a million for any help.

Ty

-----------------------------------------------------
The sizes these engines can be made are pretty impressive. I know they were used in ASA racing an supposedly would make some really good hp/torq.

Does this help at all?

Google has a little, but ASA information on their engine specs is lean.

I have to think there are some pretty bad V6's with dry sump that would make killer track cars.

Thanks for your help so far. Having an F-Body, it would look like a possible great auto X, Road Race engine. Especially being aluminum. Low weight, low cg = faster times.

Thanks,


Ty

[Fairmont Kevin]

The V6 was used in the NASCAR Busch series before they went to the lower-compression V8s. Think late 80'-early 90's. I spent some time at last year's Sebring fall vintage race talking to a guy who ran a Swisher Sweets Oldsmobile, iirc. Anyway, he says he's about the only guy still running a V6 in one of these cars, due to the high cost and obscurity of the engines and lack of knowledge to build them.

However, maybe someone in that crowd has some pieces you could start with.

http://www.hscrs.com/ is the west coast vintage stocker group.

Historic Stock Car Racing Group is the east coast bunch.

[Rohan]

Didn't Indy and Indy lites run Buick V6's?

[tyoneal]

Thanks for all the post, I'm going to start hitting the links you all supplied for further research.

I checked out GMPP and they have a lot of new parts for these V6's, some of the Blocks will yield 5.2 liters. It seams really weird to me they would have all these parts if no one was ding any racing or people weren't building something fun with them.

Here is the main link I had looked at:

http://www.gmpartsdirect.com/perform...CATID=273.html

Thanks again, and I look forward to any further thoughts you may have on this topic.

Best Regards,

Ty O'Neal

[tyoneal]

Originally Posted by Fairmont Kevin

The V6 was used in the NASCAR Busch series before they went to the lower-compression V8s. Think late 80'-early 90's. I spent some time at last year's Sebring fall vintage race talking to a guy who ran a Swisher Sweets Oldsmobile, iirc. Anyway, he says he's about the only guy still running a V6 in one of these cars, due to the high cost and obscurity of the engines and lack of knowledge to build them.

However, maybe someone in that crowd has some pieces you could start with.

http://www.hscrs.com/ is the west coast vintage stocker group.

Historic Stock Car Racing Group is the east coast bunch.

=============================================
Thanks for the link, it promises some interesting reading. I wish they had more, older, "Chrome Bumper" cars, but it's still worth further reading.

It warms my heart to see some of the older cars I used to watch as a kid. It's just really cool to see them running again, and ironically in many cases they ran faster back then than they do today. Who would have thought?

Thanks again,

Ty

[tyoneal]

Originally Posted by Don Hann

http://www.s10forum.com/forum/f107/t...3-info-131868/

http://www.s10forum.com/forum/f107/p...er-faq-114235/

=====================================
Thanks for the link. It is really helping me get my arms around the V6 world and where they shine. It's looking like the power that I am after might be better served by a LS2 or LS7. Easy to hit the numbers without stressing the engine and the parts are everything.

Thanks again,

Ty O'Neal

[tyoneal]

Originally Posted by jwvess00

The Buick 3.8 / 4.1 V6 is a 90 degree 6, but it is not the same as the Chevrolet 90 degree V6. Since your links are about the Chevy engine, I'll speak to that but I thought I'd mention the Buick engines since they're very popular in turbo trim (think GN / GNX / T-Type Regal) and have an aftermarket following.

When you're digging for parts, don't forget that the Chevrolet 4.3V6 was (is?) used in marine applications, which opens up the available GM parts that were not used in automotive applications.

The Chevrolet V6/90 started out in two sizes, 200cid V6 and 229cid, in various cars (Monte Carlo, Malibu, etc.) GM fooled around with two different odd-fire cranks in those engines before introducing the even-fire 4.3V6 in the Astro van in '85. '85 was the only year the 4.3 was fitted with a carubretor (a Quadrajet). After that, it was either a TBI engine (VIN Z) or a port-injected engine (VIN W).


Forget the 200 and the 229, as their heads are junk. The 4.3 is your best bet for availability (used in '85-'88 G-body cars, Caprice from '85-'90 or so, S-series trucks and SUVs from '88 on). This engine was used as the base Chevrolet V6 in a lot of cars in the mid-80s, but mainly as a light truck engine.

It can use a lot of SBC parts that aren't cylinder count specific (i.e. pistons, rings, rocker arms with some exceptions, etc.). The big exception here is the rods, as the 4.3 has its own rod -- SBC rods won't fit.

The turbo 4.3 was only in production for the Syclone and Typhoon, and there just aren't many of these. Factory output was rated at 280HP. Going from memory, the TBI 4.3 was 165HP, the VIN W ('92-'95 with CPI) was 205HP, and the VIN W ('96+, CSFI) was 200HP.

The best factory heads are the VIN W-engine Vortec heads.

GM used two port injection systems, and for a turbo engine you'll want a port injection intake. GM TBI systems don't like boost without a lot of work since there is a reputation of leaking boost. Turbo City may be able to help with that, if you want to go that route.

The VIN W engines have both a cam and a balance shaft, which makes them smoother at the expense of a bit of power to spin the balance shaft. I don't know anyone that has removed it, so I don't know if that affects anything (i.e. oiling system, etc.)

The first port injection system ('92-'95) is Central Port Injection, or CPI. It uses a central injector to feed a poppet valve at each port via plastic tubing. It is picky about fuel pressure (low == very bad) and the regulator is known to fail and leak fuel into the intake. You know this has happened when it runs pig-rich and the intake is very clean inside.

The '96+ has Central Sequential Fuel Injection. This system replaces the central injector with six central injectors, and keeps the poppet valve setup. GM has a kit to replace this bad idea with regular injectors. The poppet system is supposed to help improve hot starts, but I've never had a port-injected GM car that had problems with that. It seems like they were solving a non-problem to me.

The stock CSFI intake is nothing great. There are many that have modified Edelbrock intakes for port injectors. I've also seen cut-down Holley Stealth Ram intakes, and even a cut-down Ramjet intake. All of that is custom work, though.

The '96+ engines also have a unique ignition system. The distributor is just that -- it distributes spark, and that's it. It has a cam position sensor used to sync the PCM for the sequential injection, but it is not used to fire the plugs. There is a crank position sensor in the timing cover used to fire the ignition module, which is external to the distributor mounted on a bracket next to the coil. Why GM didn't just go with DIS is beyond me.

The '96+ PCMs are supported by editors like HP Tuners and LS1Edit, which should help.

Two forums that have lots of 4.3 owners that build them:
http://forums.s-series.org/
http://s-seriesforum.com/ -- this one requires registration to view posts.

==================================
jwvess:

Based on your comments about the heads, would any of these be considered in your opinion better than the, "W", heads you mentioned? If you have the time and are interested, the main link has all the parts for the racing V6 parts listed in it, take a look and see if you think a Great Engine could be made out of the offerings. If not, don't worry about it. It's Christmas and people are really busy.

Here is the poop on the CNC Racing Heads Chevy offers: (Sorry it's so long)

24502523 V6 Cylinder Head - CNC Machined
These race-prepared aluminum heads are based on the familiar 18? Bow Tie V6/90 casting P/N 10134359. Their intake runners, combustion chambers and exhaust ports are already modified for maximum performance using CNC machinery. The 18? design offers improved airflow and more efficient combustion. The CNC cylinder head's port volumes and cross-sectional areas are configured for 4.5-liter (274ci) competition V6s with 4.100-inch and larger cylinder bores. New CNC porting programs were written specifically for the V6/90 cylinder head. The V6 head's intake runners differ significantly from small-block V8 versions in both size and position. The roofs of the V6 head's intake ports are 3 inches above the deck surface. This lower runner entrance (compared to a high-port V8 head) required a different treatment to maximize airflow. The recommended intake and exhaust valve diameters are 2.150" and 1.625". Overall valve length should be 5.250" (.200-inch shorter than valves for high-port V8 heads). This head casting has been updated to accommodate CNC porting techniques and to make it more "racer friendly." Material was added to the floors and roofs of the intake runners, and the water jackets were revised to increase the thickness of the port walls. The head bolt holes adjacent to the intake ports' "long walls" are drilled for 3/8" fasteners; stepped head studs are available from aftermarket sources to fit the block's 7/16" head bolt threads. The angle of the V6 head's rocker cover rail was also changed from 17? to 14?. Bosses were added to the upper rail to reposition the hold-down bolts for the rocker cover. This revision eliminates interference between the rocker cover and the rocker arms for the two end cylinders. These heads are designed to use aftermarket shaft-mounted rocker arms. The intake rockers for the end cylinders (1,2,5,6) should be offset .550"; rockers for the center cylinders (3,4) should be offset .650". Roller lifters with .150" offset are recommended to provide pushrod clearance. Three angle valve seats are installed in the modified combustion chambers. Their 48cc chamber volume accommodates the 9.5:1 compression ratio required in several racing series that use V6 engines. Intake valve seats are of ductile iron, 2.250" OD x .312" deep. Exhaust valve seats are of beryllium-copper, 1.680" OD x .312" deep. Back angle is 12? intake / 25? exhaust. Overall length is 5.250". Valve guides are bronze, 11/32" ID. Valve springs are 1.550" diameter cups. Spark plugs have a .0709" reach tapered seat, 5/8" hex ("S" series); 3/4" reach gasketed seat, 5/8" hex head ("C" series). Recommended components are P/N 10051125 - Bow Tie intake manifold base; P/N 10051126 - Bow Tie intake manifold top; and P/N 10134325 - intake manifold gasket.
Technical Notes: Use with rocker cover P/N 12480057 only, and rocker cover gasket P/N 24502557.

Just in case you want to see the rest of the parts, here is the main link for the 90 Degree V6 Chevy Parts.

http://www.gmpartsdirect.com/perform...CATID=273.html

As usual, thanks for the efforts you've given in answering this question.

Best Regards,

Ty

[jwvess00]

Of all of the stock heads, the CSFI Vortec VIN W heads are the best choice. Then again, they are your basic stock iron truck head. Any of the GMPP heads are going to be an improvement.

The big deal with the heads you highlighted is that they're 18 degree heads instead of the stock 23 degree heads. That means that stock valvetrain parts and intake manifolds won't fit. GMPP and others will gladly sell you parts that will work, but it won't be cheap. That 5 degree change really helps them breathe, but at the expense of a lot of custom parts.