Hitman's Pontiac Trans Am Forum
Trans Am Information => Trans Am Tech => DriveTrain => Topic started by: poundinponcho on December 14, 2011, 08:59:11 AM
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I am currently assisting a friend in gathering the core parts to rebuild his 1970 TA. He has found a potential RAM AIR IV engine, but one thing about it puzzles me. It is the 9799915 block casting, date code of "J" of 69, but has the alpha block stamping WS. The heads on the engine are RAM AIR III, #12 casting. I always understood the Ram Air IV engines to be rated at 370 HP and would have WW, WH for Manual tranny cars, and XP, XN for automatic cars. I thought the WS code was Ram Air III motors. Is it possible to have a 9799915 Ram Air IV casting, but with the WS alpha code. Can someone please shed some guidance. I appreciate your help. I am going tonight to look the engine over and want to be able to advise my friend with correct information. Thanks Eddie
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Well I'm not a professional.
The only difference in RAIII and IV short-blocks were the original pistons: III's got cast and IV's got forged.
The only other way you can sort of tell is by dropping the pan and checking the main cap bolts. The only catch? Both motors got 4-bolt main caps. So why check? Because apparently I've heard from multiple sources that some RAIII blocks weren't 4-bolt!
So if it is a 2-bolt block, you know it's a mis-casting and that it's really a RAIII.
However if you have 4-bolts and by a stroke of luck have the original pistons, verify which type they are.
From what I've read the RAIII and IV blocks were basically the same thing. Best guess is someone screwed up at the plant. The "numbers guys" of the Pontiac world would LOVE to have a strike at this!
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I had a 1968 WQ (RA I) , the block was cut for 4 bolt caps and had a A/S crank. but it had 2 bolt caps on it.
wish I still had it , now that I have two 1st gens.
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Thanks for the help guys. Can you identify part numbers or anything visually that I can use to determine if the pistons are correct and original RAM AIR IV. The engine is currently apart, so I will be able check everything in detail. I will take some pics and post them so everyone can see what we're dealing with tomorrow. Thanks again.
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Wow... interesting problem to have!
Cast pistons should have a “parting line” from the casting process on the un-machined under-side of the pistons where the mold was split.
Here is a summary of the RAIII vs. RAIV from that most authoritative of sources “some guy on the internet”:
http://www.midsizebowties.net/articles/Pontiac_Ram_Air.html. (http://www.midsizebowties.net/articles/Pontiac_Ram_Air.html.)
Per the article above, RAIV had aluminum intake, forged pistons and 1.65 rocker arm ratio (vs stock 1.50 fro RAIII) as improvements over the RAIII
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Looks like the ws code was used for quite a few years in the highest performance Pontiac 400's.
The assembly line was kept moving...could have gotten a ws coded ram air 4.
The heads make the motor.
http://www.allmusclecars.com/pontiac/pbcodes.htm
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Update: I went with the potential buyer last night to inspect the engine. Turns out it was a WS code Ram Air III, 914 casting. The owner or previous owner had modified the casting number of the block from a 4 to a 5 trying to pass it on as RAM AIR IV. Once the owner realized we knew it was a fake, and that a few cylinders where eggshaped, he became upset and ask us to put our bore indicator up and close the door on the storage unit the engine was in. If anyone ever tries to trade or buy anything from David Hammons or Hammons Classic cars in Crab Orchard, KY beware and be cautious of what he tells you. In my subjective opinion, there is some questionable activity going on with their operation.
Thanks again for assistance and responses.
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Per the article above, RAIV had aluminum intake, forged pistons and 1.65 rocker arm ratio (vs stock 1.50 fro RAIII) as improvements over the RAIII
Well actually every Trans Am motor from 69-72 would have an aluminum intake, not just the RAIV. And secondly the heads on the engine of subject weren't RAIV so those pieces of info are of no use. It comes down to numbers numbers numbers.
Update: I went with the potential buyer last night to inspect the engine. Turns out it was a WS code Ram Air III, 914 casting. The owner or previous owner had modified the casting number of the block from a 4 to a 5 trying to pass it on as RAM AIR IV. Once the owner realized we knew it was a fake, and that a few cylinders where eggshaped, he became upset and ask us to put our bore indicator up and close the door on the storage unit the engine was in. If anyone ever tries to trade or buy anything from David Hammons or Hammons Classic cars in Crab Orchard, KY beware and be cautious of what he tells you. In my subjective opinion, there is some questionable activity going on with their operation.
Thanks again for assistance and responses.
I can't believe how dishonest and just-plain-horrible people are becoming simply to make a buck off of the muscle car enthusiast community. These people should be thrown into a combine. I can't believe these people sleep at night.
And why would he want to hide or be shy of out-of-round cylinders? That is something that is as common as day and night in the machining world and nothing that a bore or hone would fix..... ???
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unless he's selling a low mile engine , that shows over 100k in wear , or he was told its low miles and never checked it him self.
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I don't think--personally--mileage matters when it comes to a motor from an unknown source that shows ANY wear at all.
It'd be a fools move to not rebuild the motor regardless.
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He shy'd away due to several factors outside the owners disposition. The engine was already .030, the engine appeared to have been ran extemely hot and had severe discoloration in the cylinders, 2 of the cyliners were .070 eggshaped, and for $2K, plus having to re-sleeve cylinders, worry about deck warpage, and not to mention what may have been found under the rod and main caps, for $2000 it wasn't a decent deal by any stretch. Had it been the original numbers matching engine, it may have been worth trying to salvage, but to most people it would have been a door prop or a boat anchor.
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.070" out of round!?!?! Holy crap!
I think you made a great call.
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Well actually every Trans Am motor from 69-72 would have an aluminum intake, not just the RAIV. And secondly the heads on the engine of subject weren't RAIV so those pieces of info are of no use. It comes down to numbers numbers numbers.
[/quote]
1969 Trans Ams Total 697 642 RA III 55 RA IV
1970 Trans Am Total 3196 3108 RAIII RAIV 88
RA III motors have cast iron intakes and RA IVs have aluminum intakes, so only 143 of 3805 T/As produced in the 1969 and 1970 model years had aluminum intakes
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Well actually every Trans Am motor from 69-72 would have an aluminum intake, not just the RAIV. And secondly the heads on the engine of subject weren't RAIV so those pieces of info are of no use. It comes down to numbers numbers numbers.
1969 Trans Ams Total 697 642 RA III 55 RA IV
1970 Trans Am Total 3196 3108 RAIII RAIV 88
RA III motors have cast iron intakes and RA IVs have aluminum intakes, so only 143 of 3805 T/As produced in the 1969 and 1970 model years had aluminum intakes
You're absolutely right, for some darn reason I thought the RAIII's had aluminum.
I assumed since the 455HO's in 71-72 had aluminum intakes, that so would've the RAIII's, but I was obviously wrong.
Thanks for the correction!
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The 5 was stamped by the factory after the 4 was machined away.
Please see this thread:
400 Engine Block Numbers
http://www.gtoforum.com/f162/400-engine-block-numbers-58802/
excerpt:
Here's one for you gurus. Some time ago (about 1996) I purchased a '67 GTO project car and have had it tucked away until recently. While the body is out for blasting, I'm going thru the rest and have come up with mixed info from local sources regarding the engine. Obviously it is not original. It is a WS code block with a casting date code of H269. The heads are #12 with a casting date code of H079. Seems reasonable so far. Now the unusual stuff. The casting number of the block is 9799915. The numbers lists I have found on the web and in my books tell me it could be a RA III or in some cases a RA IV. However, the last digit of the casting number (5) is a stamp and not a part of the mold. It almost looks like it may have been ground down before it was stamped. I have yet to pull the pan to check to see if it has 4 bolt mains or not, but that will be soon. I'd be interested to hear any comments you might have on any aspect of the subject. Thanks for your time.