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H-Beam Racing rods

RootesRooter

Donation Time
Wow. I'd like to see the machining it'll take to fit the new rod on the crank - and the pistons that'll fit under the head.
 

spmdr

Diamond Level Sponsor
I talked to two crank grinders and got the same ball park price of about $150 to custom grind the cranks with any stroke.

I talked to the piston guy and the price break starts at 40, so I'll likely do 2 1/2 sets to start, when I can choose a bore size and rings.
 

husky drvr

Platinum Level Sponsor
I talked to two crank grinders and got the same ball park price of about $150 to custom grind the cranks with any stroke.

I talked to the piston guy and the price break starts at 40, so I'll likely do 2 1/2 sets to start, when I can choose a bore size and rings.

Just a quick question or two. How are you planning to deal with the squirt hole feature on the side of the Rootes rod? I wouldn't imagine the new rods have a similar feature. I doubt drilling the new rods and bearings is a practical solution, for more than one reason. Is it even something worth contemplating?
 

spmdr

Diamond Level Sponsor
That IS a pertinent question!

I don't plan to drill the rods, But if you look close at the Rod specs,

You'll see the Big end is none too wide.

Obviously, I think it is wide enough and it certainly will not slow down the oil thrown off the crank.


My observations of engines in the upper performance levels typically have extra oiling for the pistons

to cool them.

I don't think the factory hole is the answer.


I HOPE to get to the level of performance that extra piston cooling would be a good thing.


And I would likely plumb directly to get limited flow, full time spray.


BUT, all that is likely down the road a bit from where I'm going, in the near future.
 

spmdr

Diamond Level Sponsor
BTW, I rebuilt a 1725 Alpine engine with a crank ground down to 1.875, so 1.880 is not breaking any new ground.

And I know of another "1725" Alpine engine with the crank Stroked and ground to 1.771.
 
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mototron

Donation Time
I have built 1725 motors , with with eagle h beam Chevy 6cyl rods , arp bolts
offset ground the crank to to the chevy journal size and had custom made JE flat top Pistons
the rods fit through the bore easily , I might have the JE custom spec # if anyone is interested
My big problem was keeping head gaskets , i was running about 12.5 to 1 compression
 

PROCRAFT

Donation Time
I have built 1725 motors , with with eagle h beam Chevy 6cyl rods , arp bolts
offset ground the crank to to the chevy journal size and had custom made JE flat top Pistons
the rods fit through the bore easily , I might have the JE custom spec # if anyone is interested
My big problem was keeping head gaskets , i was running about 12.5 to 1 compression
O Ring the block.
 

alpine_64

Donation Time
O Ring the block.
No need to O ring it.. Just weld up the cresent water passages and drill them to be 2 holes. Then custom headgasket with the 2 holes instead of the stock with the weak area of the thin bridge between water jackeets and combustion chamber
 

spmdr

Diamond Level Sponsor
I have been doing more and more research on engine theory (and components there of)

and just stumbled on this Quite Comprehensive video on rod ratios/lengths.

Even though I have already made my decision, this may help if you are on the fence.

FYI rod ratios:

1592 ( 5.750 rod 3.00 stroke )

Long rod 6.260

Stock ........ 1.916
Long rod .. 2.086

1725 ( 5.625 rod 3.250 stroke )

Stock ........ 1.730
Long rod .. 1.926

Hmmmm !! I JUST realized how the Long rod makes the 1725 effectively the SAME Rod ratio

as a Stock 1592!

Hmmmm, imagine that?

DW

 
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jdoclogan

Platinum Level Sponsor
Outstanding find Dan. It provides some physics to the various scenarios for engine builds.

The presenter's mathematics is increasing the rod length by 100% (240 vs 120). Your long rod length over stock (6.26 vs 5.75) is only an increase of 8.8%. I don't believe the vibration issues are minimally addressed for your increased rod length. I think one needs to look at other advantages or disadvantages to increased rod length in our Alpine engine application. Less vacuum comes with the longer rod. We already know that the Alpine engine has a flow problem and maybe the shorter rod is better. However, I believe the increased valve sizing addresses that issue of flow rate to its maximum capability (https://forum.sunbeamalpine.org/index.php?threads/head-flow-test-results.31401/). That being said, I still think that the impact of your longer rod is negligible to flow rate. Explosive firing in the combustion chamber appears to be less with a longer rod. Again yours should be negligible. I think the one advantage is increased cylinder capacity with the longer rod. In other words, increased stroke can provide more volume and thus more power. Does it provide 8.8% more power over stock, probably not.
 

spmdr

Diamond Level Sponsor
Just for the record, the 8.8 % change is with the 1592 rods,

Already quite a high Rod/Stroke ratio with stock rods, to the long rods!

The 1725 with a LONG rod gets a 11.2 % change from stock...

Even though I picked the Rod first, the Main Goal was a major Piston change.

Alpine engines, in general, have a decent Rod/stroke ratio.

But that is about the only good thing I can say about the Alpine rods.

With the Tall Alpine engine block, Longs rods are more of a default.

And as it turns out, Not a bad thing.

So if you're going to change rods, get as much advantage as you can,

in the direction you are going.

At this point, I would remind that this Thread is about RACING,

Street engines are a different ball game.

BUT, with the smaller engines, Racing and Street driving is BECOMING, as They say...

"a distinction without a Difference ".... ;-)

DW
 
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alpine_64

Donation Time
David Vozard has a channel that i try and watch when i can.. His presentation is like amature hour in an 80s public broadcast... And he seems quite an odd guy... But get past that and into his knowledge....

The info on the crank mods is really interesting. Didn't go into knife edging the crank counter weights... Instead a different approach.. Also the profiling for aero and the flange mods are interesting

 

spmdr

Diamond Level Sponsor
Got to love Vizard!

However, Every time you make a statement,

And Vizard makes a LOT of them, you have to be ready

to take the heat from those that want to misapply

the statement,

Or attribute to it more than is said.

And Vizard is guilty of some of that activity as well,

when he criticizes other's statements.

The good news here is that he confirms the world of rod/stroke

ratios.

And this reminds me, when it comes time to Mod the crank for the new

rods and lighter reciprocating weight, I have a chance to have my way

with the counter weights...and shapes!

AND Miro-polish that Crank!

And other tricks... like Crank scrapers in the crank case...etc.


It sure would be GREAT to have Vizard take a fresh Shot at the OLD

Alpine HEAD!

He clearly has more Tech now to apply toward fixing that Bugger.

I HAVE and could spend a LOT more time on Vizard's vids!!

DW
 
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spmdr

Diamond Level Sponsor
Also, one other tid-bit I picked up from different sources, about the world of Rod ratios,

better flowing heads favor Short Rod ratios .

And weaker flowing heads favor longer Rod ratios.

And We know what side of that fence We are on...

DW
 
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