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  #11  
Old 04-06-2011, 12:26 AM
442w30 442w30 is offline
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Default Re: Any truth to this 396/402 update?

But, Kim, using your logic, then the 265-283 would have been for emissions too.

I think, in most cases, there was a natural progression to meet the demands of more power for cars that were gradually getting heavier. However, the 396-402 nudge was so negligible that it must've been done for other reasons, such as emissions.
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  #12  
Old 04-06-2011, 01:44 AM
JoeG JoeG is offline
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Default Re: Any truth to this 396/402 update?

Just tryin' to thing back a bit........pretty sure it's in a magazine I have somewhere..??
Maybe some emission cave-in in design..??.But part of the chatter back then was some sort of hood clearance problem with the L78 highrise manifold in the 1970 Chevelle or Camaro....??
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Old 04-06-2011, 04:43 AM
Bill Pritchard Bill Pritchard is offline
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Default Re: Any truth to this 396/402 update?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 442w30</div><div class="ubbcode-body"> He bought the car off the lot in 68 after getting home from Viet Nam.</div></div>

The statement above is the reason I inquired as to what model year car was in question. If this person bought the car in 68, then it was either a 68 (or older) or a early production 69 model. In either case, there was no wholesale .030&quot; overbore of 396 engines from the factory in that time frame, hence such an example could indeed have been some sort of 'mistake' from the factory.
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  #14  
Old 04-06-2011, 02:45 PM
442w30 442w30 is offline
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Default Re: Any truth to this 396/402 update?

Do you think the factory would have sold a car with an overbore like that?

It was a Mopar board, so for all I know he could have been getting the year wrong. It was a sub-topic/tangent in a debate about 400 SBC and BBC. Getting 3 pages worth of Brand X there without the haters coming out was interesting. :-)
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Old 04-06-2011, 07:42 PM
Bill Pritchard Bill Pritchard is offline
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Default Re: Any truth to this 396/402 update?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 442w30</div><div class="ubbcode-body">It was a Mopar board.....Getting 3 pages worth of Brand X there without the haters coming out was interesting. :-) </div></div>

Wow, that had to be a rarity, indeed!

Hard to say if the factory would have produced an engine like that or not prior to late in the 69 model year [img]<<GRAEMLIN_URL>>/dunno.gif[/img] If it was a very late production 69 model car, then there's little doubt that it came that way.
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  #16  
Old 04-07-2011, 12:26 AM
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Default Re: Any truth to this 396/402 update?

If a 396 built for the 1969 model year has a 3 letter suffix, it is the 402. I has an 08E of 69, 69 Camaro, 3 letter suffix, 402 inch....Joe
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Old 04-07-2011, 02:37 AM
Kim_Howie Kim_Howie is offline
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Default Re: Any truth to this 396/402 update?

The 265 was changed to a 283 in 1957 had nothing to do with what was happening in 1970 and up. The HP was lowered each year after that. Hey that is what I was tolded back then.
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Old 05-02-2011, 06:45 PM
Kurt S Kurt S is offline
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Default Re: Any truth to this 396/402 update?

No 396 motor would be repaired with an overbore by the factory. It's not worth the time, they would just scrap it and do it again.

The 396 to 402 was changed effective the (regular) 1970 model year, which means it went into the late 69 Camaros.

From http://www.camaros.org/drivetrain.shtml#PadStamps
In 1970, engine application codes changed from a 2 digit to a 3 digit code by adding a prefix letter to the code. The prefix letter for passenger cars was C and the prefix letter for trucks was T. For example, the 1969 JF engine code became CJF in 1970. This change did affect late 1969 SS396 Camaros (but no other 69 Camaro model). Per the Sep-Oct 1969 Chevrolet Service News, these big-blocks with the 1970-style engine codes actually are 402 cubic inch engines. This was simply a .030 overbore of the 396 block. All advertising and sales literature still referred to the 402 engine as the 396.
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  #19  
Old 05-02-2011, 08:27 PM
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Default Re: Any truth to this 396/402 update?

Haven't we discussed this here in the past and the extra bore was an economical way to intentionally total more than 400 actual cubes thus resulting in these engines being classed under a different and less stringent (and cost) emissions class?.
Being the 1970 production year was when GM dropped their no more than 400 cubes in an A-Body rule, is this perhaps the actual reason?.

[img]<<GRAEMLIN_URL>>/hmmm.gif[/img]
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  #20  
Old 05-03-2011, 03:47 AM
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Default Re: Any truth to this 396/402 update?

I thought the overbore was to improve emissions.
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