Two versions of the R3 Avanti engine???

[VtMike]

Today I was surfing around the 'net and came across an article from the Pressreader dated July 19, 2018.  It can be found here:  https://www.pressreader.com/australia/unique-cars/20180719/282737702601107

The thing that caught my attention was that the writer claimed the R3 engine was available in two versions, and the second one had two 4 bbl carbs inside the Air Box and something like 430 hp.

I know I am new 'round here but I never heard of this alleged dual carb version of the R3.  Is this guy telling the truth?

While I am asking questions, I will ask another one:

I read somewhere that, when Andy Granetelli (sp?) built the R3 that Hot Rod magazine tested back in the early days, he didn't build it the way factory R3s were built.  He did increase the engine from 289 to 299 cubic inches, but he did that by stroking the engine rather than boring it out.  The suggestion in the article was that a stroked 289 would have more torque than one that was bored out, and Andy wanted Hot Rod to test an R3 that would perform as well as possible in the 0-60 and 1/4 mile tests.   The article also suggested that such shenanigans weren't atypical of the time, and said GM provided Hot Rod with a 421 powered GTO rather than the factory 389.  Sure enough, the Hot Rod mag GTO outperformed any stock GTO every built.

So, anyway, I was wondering whether stroking a 289 to 299 was something that anyone else has done, and whether that is a practical approach to gaining more performance?

Mike

[Rob Dudley]

The simple answer is NO. He isn't telling the truth. There were different engines as the R3 was being developed but that is another myth. the final engine was 304.5 single enclosed carburetor supercharged engine with special heads and other peripheral parts putting out an estimated 335 horse power in stock form. 

Rob

[mfg]

On 9/25/2018 at 10:10 PM, VtMike said:

Today I was surfing around the 'net and came across an article from the Pressreader dated July 19, 2018.  It can be found here:  https://www.pressreader.com/australia/unique-cars/20180719/282737702601107

The thing that caught my attention was that the writer claimed the R3 engine was available in two versions, and the second one had two 4 bbl carbs inside the Air Box and something like 430 hp.

I know I am new 'round here but I never heard of this alleged dual carb version of the R3.  Is this guy telling the truth?

While I am asking questions, I will ask another one:

I read somewhere that, when Andy Granetelli (sp?) built the R3 that Hot Rod magazine tested back in the early days, he didn't build it the way factory R3s were built.  He did increase the engine from 289 to 299 cubic inches, but he did that by stroking the engine rather than boring it out.  The suggestion in the article was that a stroked 289 would have more torque than one that was bored out, and Andy wanted Hot Rod to test an R3 that would perform as well as possible in the 0-60 and 1/4 mile tests.   The article also suggested that such shenanigans weren't atypical of the time, and said GM provided Hot Rod with a 421 powered GTO rather than the factory 389.  Sure enough, the Hot Rod mag GTO outperformed any stock GTO every built.

So, anyway, I was wondering whether stroking a 289 to 299 was something that anyone else has done, and whether that is a practical approach to gaining more performance?

Mike

According to the former owner of the Hot Rod Magazine 1963 Studebaker Avanti test car, (63R1025), who actually purchased the car directly from the Granatellis, they told him that particular engine was stroked to gain more 'low end' torque for drag strip match races.

I guess the only way to know for sure is if someone, one day, opens up & measures that interesting Avanti R3 engine!

[Dwight FitzSimons]

There were two versions of the final R3 engine: (1) the first with a 276 deg. cam and single valve springs, and (2) the other with a 288 deg cam and dual valve springs.  The 288 deg one produced more power.

--Dwight

[Gunslinger]

I have seen claims that the final R3 crate engines that were sold by the Granatellis were shipped with R2 heads as there were no more genuine R3 heads available.  

[mfg]

22 minutes ago, Gunslinger said:

I have seen claims that the final R3 crate engines that were sold by the Granatellis were shipped with R2 heads as there were no more genuine R3 heads available.  

Yes, that has been reported several times....Do you suppose the Granatellis revealed to the purchaser he was buying an R3 short block with R2 heads?.....Or possibly they reworked stock R2 heads so they 'flowed' more like the real McCoy??

[PackardV8]

Paxton sold so many R3 permutations over the years, it's impossible to know what the customer was told and when.

In addition to running out of R3 heads, they also used up all the R3 connecting rods and there were several bitsa versions sold with stock rods.

jack vines

[Mrelmtow]

On 12/20/2021 at 4:11 PM, mfg said:

According to the former owner of the Hot Rod Magazine 1963 Studebaker Avanti test car, (63R1025), who actually purchased the car directly from the Granatellis, they told him that particular engine was stroked to gain more 'low end' torque for drag strip match races.

I guess the only way to know for sure is if someone, one day, opens up & measures that interesting Avanti R3 engine!

That just might happen soon!

[silverstude]

My question is, that if Studebaker sanctioned the Granatellis to build the R3's, using the resources of the Studebaker Corporation, then the Foundry had to have patterns, etc for all the special engine components.  So where did these items needed to produce R3 heads and manifolds go?

[mfg]

22 hours ago, silverstude said:

My question is, that if Studebaker sanctioned the Granatellis to build the R3's, using the resources of the Studebaker Corporation, then the Foundry had to have patterns, etc for all the special engine components.  So where did these items needed to produce R3 heads and manifolds go?

Yes, you're speaking of patterns for the special R3-4 heads, exhaust headers, and the aluminum intake manifolds, both single & dual quad...Well, I'd guess it was all scrapped.

[PackardV8]

On 1/11/2022 at 3:03 PM, mfg said:

Yes, you're speaking of patterns for the special R3-4 heads, exhaust headers, and the aluminum intake manifolds, both single & dual quad...Well, I'd guess it was all scrapped.

Not all.  IIRC, the R3 heads used the same cope and drag boxes as the regular heads, but with different core patterns for the ports and combustion chamber.  Some of the R3 core box patterns were salvaged and IIRC, Lionel Stone borrowed the intake port portion when he was trying to get an aluminum R3 head into production.  Part of the problem with that attempt was the cores were for iron and aluminum shrinks 50% more when cooling:

Iron	1/8" per foot
Aluminum	3/16" per foot

 

jack vines

[mfg]

26 minutes ago, PackardV8 said:

Not all.  IIRC, the R3 heads used the same cope and drag boxes as the regular heads, but with different core patterns for the ports and combustion chamber.  Some of the R3 core box patterns were salvaged and IIRC, Lionel Stone borrowed the intake port portion when he was trying to get an aluminum R3 head into production.  Part of the problem with that attempt was the cores were for iron and aluminum shrinks 50% more when cooling:

Iron	1/8" per foot
Aluminum	3/16" per foot

 

jack vines

VERY interesting!.....Thanks for that info!