1592 for Racing

[jdoclogan]

I have a very late Series IV 1592 engine that I was intending on using for the #41 Sebring Alpine project. I wanted to go the "full Monty" on the build. What I found was that it had been rebuilt at some point and has been bored to .060. There isn't any obvious issues (cylinders look very clean, but, no hash marks so wear has occurred) other than a blown head gasket at #3 cylinder. Probably why it was pulled with the all synchro transmission and ended up with me. Any thoughts on using this for my #41 project?

The pistons cleaned up real good, but, I want to use flat head pistons, Chev 350 rods, and Vizard head for the #41 build.

Pistons are marked .060

 

[bernd_st]

With plus 0.060 oversize/ no hash marks you'll need to go for liners. Possible, but a bit costly. Needless to stress but they need to be installed properly, otherwise you'll get head gasket sealing issues. Many of the 3 bearing cranks are slightly bent. Nothing which a good engine shop can't fix, but it all adds up. While you are at it get the crank nitrided. Chevy rods are a very good idea for the 1592 . Did some initial studies accordingly, check my thread at UK forum.

Vizard mod / flat top pistons are a good choice only issue is to get high quality flat ones. Still curious regarding those JP Aussie pistons specifically their poor ring design...

 

[spmdr]

At this point, I think the Chevy rod route (350/6/4) is a bit old school.

The better route may be a smaller rod with smaller pin sizes and longer.

GT6 is closer to what I am suggesting, but a custom version.

BTW, +.060 is not a problem. (except by some "rules")

 

[jdoclogan]

Thanks gents. Dan what would be the rules?

 

[alpine_64]

Jerry i sent you a zoom invite a couple days back..did you get it?

 

[jdoclogan]

Jerry i sent you a zoom invite a couple days back..did you get it?

I sent you an email.

 

[bernd_st]

Chevy rods - oldschool ?Hmm first time to hear. Don't know of any better/lighter rods vs. cost plus they are suiting the 1592 specifically well...

 

[Alpine 1789]

Just curious: why do you say the Chevy Rods suit the 1592 specifically well?

 

[bernd_st]

Here is an excerpt of my initial studies which I shared in UK Forum earlier:

Chevy rods on 1592cc: Actually they would fit even better (compared to 1725cc )since they also have the 2" big end diameter. Same as for the 1725 the crank must be slightly ground at the big end sides (+ 1mm would make them suit perfectly). Small end needs to be slightly bored to accept piston pin (same as for 1725).Ultimately the Chevy rods are substantially lighter than the originals

After all this confirms my theory that a real 1592cc screamer could be built out of the components mentioned

.

P.S. The weight saving per rod is around 180g ; total therefore = 720g -> Very substantial for a smaller displacement engine...

 

[Alpine 1789]

Thanks. I will eventually be building an engine for my S3. I have the original engine, which was rebuilt by the PO and never installed, along with a spare S3 engine - it came out of a S3 GT that was being converted to a Tiger and I assume became scrap - and a spare 1725. My plan is to save the original engine and build a screamer; I am just not sure which engine to start with.

Lots of time on this one! I have to finish my V6 and at least one of my two (half ownership) Tigers before I can contemplate starting work on the S3.

 

[husky drvr]

Here is an excerpt of my initial studies which I shared in UK Forum earlier:

Chevy rods on 1592cc: Actually they would fit even better (compared to 1725cc )since they also have the 2" big end diameter. Same as for the 1725 the crank must be slightly ground at the big end sides (+ 1mm would make them suit perfectly). Small end needs to be slightly bored to accept piston pin (same as for 1725).Ultimately the Chevy rods are substantially lighter than the originals

P.S. The weight saving per rod is around 180g ; total therefore = 720g -> Very substantial for a smaller displacement engine...

bernd_st,

The Chevy rods are longer center to center than those in a 1725 engine, which is why the piston crown needs to be machined. The Chevy rod is 0.050 inch SHORTER than a 1592 rod (5.70 inch c-to-c Chevy to 5.75 inch c-to-c 1592). You would need custom pistons to maintain compression. If you use custom pistons, then you should specify the use of the smaller, lighter Chevy wrist pins for a greater saving of reciprocating weight.

 

[spmdr]

Some Vintage Race Groups have Rules limiting over bores to something like .040

I'm not sure how many enforce those rules.

And if a 1725 is OK, an over bored 1592 shouldn't be a problem.

Depending on the goal, the Chevy rod route IS old school.

You can end up with lighter stuff with smaller, longer rods.

If the extra cost is worth it, is up for debate.

If you go custom everything, Chevy is most definitely old school.

 

[jdoclogan]

I appreciate the "rule" clarification Dan.

 

[Jimjordan2]

Just as a mention, I do know that Sunbeam Specialties has.060 rings. Or they did last year. I know they said pistons were NLA, but they said there were many sets of rings.

 

[bernd_st]

Ok, perhaps I'm a firm believer in old school

0.05" isn't such a big deal so just get the blocked decked a bit an you will be there. See picture here which was taken when I made the first examinations:

 

[jumpinjan]

Chevy rods are not old school (whatever that phrase means), if anything they are viable solution, but getting harder to find, unless you go with Crower's new rods.
Jerry, the Series IV block is my favorite 1600 block because it is made with new sand core designs. Much iron is eliminated to save weight.
I have machined the 1600 blocks to use the 1725 oil pump and I would like you to engineer a new way of getting more oil up on the springs & rocker arms. That should help a lot.
Jan

 

[jdoclogan]

Chevy rods are not old school (whatever that phrase means), if anything they are viable solution, but getting harder to find, unless you go with Crower's new rods.
Jerry, the Series IV block is my favorite 1600 block because it is made with new sand core designs. Much iron is eliminated to save weight.
I have machined the 1600 blocks to use the 1725 oil pump and I would like you to engineer a new way of getting more oil up on the springs & rocker arms. That should help a lot.
Jan

Good to know Jan. "getting more oil up" this opens up a whole additional investigation. However, this fits my current retired status too which everyday is a Saturday.

 

[alpine_64]

Chevy rods are not old school (whatever that phrase means), if anything they are viable solution, but getting harder to find, unless you go with Crower's new rods.
Jan

Jan ,

Manley offer many variations of aftermarket chev rods.. Depending on what weight/strength/ budget you have

 

[husky drvr]

Ok, perhaps I'm a firm believer in old school

0.05" isn't such a big deal so just get the blocked decked a bit an you will be there. See picture here which was taken when I made the first examinations:

You're right. It's just twice the spark plug gap.

Just don't like the idea of taking that much material out of the block/head interface. It would probably have a large enough effect on valve train geometry to require new custom pushrods. It just depends on your priorities and budget as to how your compromises develop.

Think I would pick these rods and custom pistons. Even this choice is at the too long limit for rod length/stroke ratio in a 1592. At least custom pistons give the ability to choose how to apply other design choices. And comparing the price to 1592 rods in SS catalog, they really aren't far out of line.

https://www.summitracing.com/parts/sca-66000206sgl/make/chevrolet

 

[husky drvr]

Good to know Jan. "getting more oil up" this opens up a whole additional investigation. However, this fits my current retired status too which everyday is a Saturday.

More oil shouldn't be too difficult. The question is how much more oil as compared to how much excess oil flow is available to use. Just a thought.