VIN B VIN W VIN Z

[doyoulikeithere]

Some of you most likely know what the 8th digit in your VIN code stands for. It represents the type of engine you have and how it is fueled, basically.

Some of you may have even heard of a rare performance package offered on a few early Mvans which included a "HO' high output engine.
Some people say it was in 'some' of the GT/RS series of M vans. Apparently these "HO" vans have a "B" in the eighth digit of the VIN, at least that what I've read in the popular article I've read, by Doug Anderson. http://www.enginebuildermag.com/Article ... y_262.aspx

Anyways, I wonder if any of y'all who have ever had or seen a VIN B van might speak up and tell us more...? Hopefulle pictures?
I think what sets the "HO" engine apart is the cam, mostly. And I know that My 95 VIN W exhaust manifolds and Y pipe are huge compared to the VIN Z.
I've got a couple of rare 5 speed VIN Zs, but have never seen a VIN B. I would like to know more about them.... Just curious who has seen one mostly...

The Syclone / Typhoon & Fiero forums have a list of stock cams listed and one of the Gen 1 cams that "They' list as ’90-’91 VIN Z has some big numbers on it "– Lift (I/E) – .403/.450"!
http://myfiero.oceanmoon.com/engineidea ... -cam-specs
Factory 4.3L Cam Specs

* ’96-’00, VIN W, w/ balance shaft – Lift (I/E) – .415/.429 – Dur @ .050 (I/E) – .191/.195
* ’93-’96, VIN Z, w/ balance shaft – Lift (I/E) – .376/.402 – Dur @ .050 (I/E) – .183/.193
* ’92-’95, Vin W, w/ balance shaft – Lift (I/E) – .432/.440 – Dur @ .050 (I/E) – .208/.208
* ’91-’93, ZR9/Z79, Syclone/Typhoon – Lift (I/E) – .351/.386 – Dur @ .050 (I/E) – .179/.195 (Ductile)
* ’90-’91, VIN Z, Astro/Safari – Lift (I/E) – .403/.450 – Dur @ .050 (I/E) – .202/.213 (Steel)
* ’87-’94, Vin Z, w/o balance shaft – Lift (I/E) – .351/.386 – Dur @ .050 (I/E) – .179/.195 (Ductile)

[HPbyStan]

My '04 has a "X" for the 8th digit.

[1Gary]

I think the way GM handled the whole history of M models was kind of confusing and conflicted.They seem to imply the Safari's are worth more,had a turbo 4.3 in the cyclones,but never put them in the M bodies,had the R/S's but seem to want not to stray too far from the soccer mom vehicle,built something that is way too easy to swap in a V8 and almost seems that was a consideration,but never put in a V8.Now this was uncovered and I do find it interesting.I had before this never heard of a B in the Vin before or for that matter a HO engine.All I knew about the R/S's was a quicker steering box,rear OEM sway bar and some badges.Now you guys are talking about a bigger cam.Very interesting.

I have always been curious and find the history/try to understand how decisions where made about the direction of these vans came about.

[HPbyStan]

Jeez Gary, trying to find logic in GMs Astro/Safari planning will drive ya nuts.

[1Gary]

Jeez Gary, trying to find logic in GMs Astro/Safari planning will drive ya nuts.

LOL-well maybe.

[Kidhauler]

I had a h.o. Engine in my 91 8 passenger Astro. The old owner had also put some heavier springs in the trans so it shifted better. I loved that van right up untill a dodge charger burried itself deep in the drivers door.

[doyoulikeithere]

I had a h.o. Engine in my 91 8 passenger Astro.

So KH, Was that a VIN B ? How did you identify it as an 'HO' engine ?

[Kidhauler]

It had H.O. Stickers on the back plus I bought it off the origional owner who ordered the more power and a tow pack that van had some good jump to it. I can look around and see if I have any old paperwork from when it got totaled that might have the vin on it. Off the top of my head I think it had a b in the vin but that was several years ago now.

[crazyvanman]

I read recently on wikipedia (i think it was) that my "w" engine was posta be 200hp. So what is posted hp for the HO engine? How bout torque.

[1Gary]

What I can add to this is forever "we" have been advising members the biggest bang for your buck is a rear end ratio change and the logic behind that is no matter what the physics of a relative small c.i. engine is the power band is going to be higher in the rpm range.So you are spinning them up alittle more to get them into their power band.

The other part of this is NO part such as a cam swap is a stand alone part that makes any sufficient changes.That engine builds need to be built on the basis of matched parts builds where can choices are heavily reliant on scr's and dcr's and then induction and exhaust.But first and foremost cam comparability with compression ratio or scr's. Here is the link:

http://www.crankshaftcoalition.com/wiki ... patibility

And again because of 4.3 engine size it will have a power band higher in the rpm range and not off idle.A good all around rear end ratio is 3.73's and if it is a awd you have to have a matching front end ratio to the rear end one.

The saving grace is all these vans,short of the stick shift T5 ones that are kind of rare, come with auto trannies that do have a low first gear and a o/d that is .75.It is a attempt to have your cake and eat too with getting a heavy vehicle moving(say these vans's wt is 4,xxx range)and still have somewhat reasonable gas mileage in o/d.But still there is a huge jump in these auto trannies from first to second.Before there wasn't any solution to that,but now there is a trans company that offers a better second gear ratio.The name of that company escapes at the moment.A common mod to these auto trannies is a shift kit from "trans to go",vett servo,and a .05 boost valve.That helps with firmer shifts.We have a member who's 502 bbc later model Safari had a programmable on the fly aftermarket shift kit in it where he could dictate the shift points and how firm the shifts are.

Why the long explanation??. It is a quick overview of what has been done before on these vans and what the logic behind it was in terms of the 4.3's power band.

Lastly,we have had members that installed turbo's on them from the gm style like the oem turbo pick-up trucks to downstream aftermarket turbos.What is common on them is a cam that doesn't have a huge overlap or long duration to capture the turbos boost and a waste-gate set so not to melt the cast pistons from that the oem engines have in them.Cams for this application and can timing events are specific to boost adders.