• Welcome to the new SAOCA website. Already a member? Simply click Log In/Sign Up up and to the right and use your same username and password from the old site. If you've forgotten your password, please send an email to membership@sunbeamalpine.org for assistance.

    If you're new here, click Log In/Sign Up and enter your information. We'll approve your account as quickly as possible, typically in about 24 hours. If it takes longer, you were probably caught in our spam/scam filter.

    Enjoy.

Rods for the 1592cc motor

sunbeam74

sunbeam74

Silver Level Sponsor
I have been doing a bit of work to change to the chevy rods in the 1592 engine. There are some challenges but it seems it may work. Technically, the Chevy rod is closer to the 1592 rod than the 1725.

I was curious what some of the advantages might be in relation to weight. So, here are some details:

Stock rod: 726grams (up to as high as 740)
Rod from the Sports Car Forum Alpine: 534 grams with a lot of lightening work
Stock Chevy I6 rod - 560 grams (but I haven't weighed one myself - this information was via a catalog)

So, the Alpine rod could be just as light or lighter but it is a lot of work.
Now here are the technical challenges to fit a rod to the 1592 engine.

1) The bolt to bolt dimension of the big end of the chevy rod is larger than the cylinder. I think there are ways around this but it is challenging since the pistons can't be loaded from below.

2+3) Press fit wrist pin and the rod is .051" shorter
I probably will bush the little end of the chevy rod and go to a new wrist pin diameter with custom pistons which will account for the extra .051" of piston height.

I am a bit worried about the area around the oil pump. I remember Jarrid had issues with a Crower rod just missing the pump.
 
jumpinjan

jumpinjan

Bronze Level Sponsor
The big ends will fit in the bore with some slight deburring on a disk sander. I made a quick measurement and I got about 0.028" shorter. That's trivial which could be compensated for when decking the block anyway. I don't know why you want to have a press fit on the pins? I had the small ends honed and they did a very good job with the fit. There's not enough meat there to open them up for bushings. Read my article and Jim Stone's article on the Chevy rod conversion.
Jan
 
sunbeam74

sunbeam74

Silver Level Sponsor
Jan,

I think the floating pin would be better for the race motor.

As far as bushing the little end I was planning to step down in wrist pin size so it would require little material removal. Just prepare the end for a bushing and press in. Of course, I have to have new pistons made anyway so Venolia can accomodate a wrist pin size change.

However, Now that I think about it more... I may run without a bushing and run steel against steel. It shouldn't be a problem as long as the engine is warmed up before going hard.

Decking the block is an option, too. I was pretty sure the Alpine rod was published as 5.751" but I haven't measured one either.

Steve
 
V

V6 JOSE

Donation Time
Steve,

Do you really want to run steel against steel, especially in such a high stress area? Remember that this engine will be running close to red line a lot of the time. A smaller pin will also be weaker than the stock pin. Personally, I would rather run pressed pins that were bigger, and not risk problems with smaller pins and steel on steel wrist pins letting go.

Why not just run a set of Chevy rods, with bigger pins and rod bushings? I doubt that anyone will be taking your engine apart to see if you are running anything other than the stock rods.

Jose :)
 
sunbeam74

sunbeam74

Silver Level Sponsor
Jose,

I would have to run a smaller wrist pin IF I were to bush the little end of the Chevy rod. As Jan mentions there isn't enough meat in the little end of the Chevy rod to remove material to stay with the standard pin size AND put a bushing in.

If I just run the rod without the bushing it should be fine. I get the impression from the machine shop I work with that they have done this on other applications for racing, too. I would have thought it to be bad, too.

It really should be a clean installation... maybe easier than the 1725? (not that 1725 is more difficult but the 1592 may require less work)

Steve
 
R

RootesRacer

Donation Time
sunbeam74 said:
I am a bit worried about the area around the oil pump. I remember Jarrid had issues with a Crower rod just missing the pump.
Click to expand...

It didnt just miss, the sharp edges of the rods actually hit the pump mounting flange and the stock mounting HW.

No big problems though, the pump flange can be tweaked with a grinder and the stock HW replaced with studs and a smaller "jet-nut".

Steve why are you beating this thing to death? just get the I6 rods and narrow the big ends to alpine width, OR as Jan prefers, have the crank journals widened to the wider I6 rod and be done with it?
You sure as hell dont want to be welding on a set of chebie rods to increase the BE width, BTDT bought the shirt, ruined the rods.

The stock rootes rods will NEVER outperform the strength and metalurgy of modern forged rods at 740 or 560 grams (hint it has to do with the fasteners).


Oh, and the rootes pins are SOOOOO heavy compared to stock chevy pins, let alone higher performance tapered pins.

If you are having pistons made, why on earth would you screw around with anything rootes in the rotating mass except the crank?
 
husky drvr

husky drvr

Platinum Level Sponsor
Jose,

It might be hard to believe but the Rootes 1592 wrist pin is about 0.011 inches larger in diameter than the Chevy wrist pin ( your mileage may vary).
Typical Rootes over engineering? :rolleyes:
 
skywords

skywords

Donation Time
Manta has Quad 4 Titainium rods avialable. I wonder if they would work in the 1592? Just a thought.
 
sunbeam74

sunbeam74

Silver Level Sponsor
Jarrid,

It is the I6 Chevy I am talking about.

BTW, I may get a few extra sets of pistons and rods if anybody is interested:

.040" flat top forged pistons set up for the I6 Rods
I6 chevy rods magnafluxed, balanced, and dressed for use.

Of course, these are for the 1592cc engine.

Steve
 
jumpinjan

jumpinjan

Bronze Level Sponsor
They will make custom billet cranks for 4-cylinder engines. Wow, impressive.
Custom3.jpg
 
sunbeam74

sunbeam74

Silver Level Sponsor
BTW< I don't think I ever posted the total weight savings with the Chevy rods and Venolia pistons. About 42 ounces total.

This should be a nice 1592 (actually with the oversize pistons somewhere around... 1640cc engine)

Steve
 
Eleven

Eleven

Platinum Level Sponsor
1967 Gcr

V6 JOSE said:
Steve,

Do you really want to run steel against steel, especially in such a high stress area? Remember that this engine will be running close to red line a lot of the time. A smaller pin will also be weaker than the stock pin. Personally, I would rather run pressed pins that were bigger, and not risk problems with smaller pins and steel on steel wrist pins letting go.

Why not just run a set of Chevy rods, with bigger pins and rod bushings? I doubt that anyone will be taking your engine apart to see if you are running anything other than the stock rods.

Jose :)
Click to expand...

says rods, pistons and crank are open. Double check my reading of it so depending on your club, the substitutions may not be illegal. You can find a copy of the PCS and GCR for 1962, 1967 and 1969 on SOVREN.org under rules.

Tracy
 
sunbeam74

sunbeam74

Silver Level Sponsor
I don't believe that any clubs restrict rods.

I think all they care about is the displacement, carburation, and most restrict roller rockers (I believe the SVRA allows roller rockers/cams).

Steve
 
Jim E

Jim E

Donation Time
Jan,
For a OEM rod Standard Crankshaft sells reman units, think they are around $25 each but it has been a while since I bought a set from them. They will also grind the crank to the chevy rod big end width for you.

As we have said before this may be the best all around rebuild for either motor 1600 or 1725. The price of the OEM rods from Standard is near what it cost to resize a set of stock rods. Then the Chevy rod bolts got to be a huge improvement. What we need now is a aftermarket piston supplier to have a part number deal for a nice forged piston in flat top and dish One for each motor.
 
sunbeam74

sunbeam74

Silver Level Sponsor
The pistons/wrist pins/retainers/rings were about $585.00 with shipping from Venolia. They claim no discount for volumn otherwise I would have ordered 3 sets. But it would never hurt to ask.

I have to believe they could provide dished pistons, too.

Wonder what the weight of the lightened Eagle rods would be.... they don't list that.

Steve
 
T

Tom H

Platinum Level Sponsor
Steve, Jan,

My Venolia Pistons, rings, wrist pins, and retainers were only $473 incl shipping. They are dished with about 4.3 cc of vol in the dish. I asked for 5 cc, but I measured 4.3 when I got them in Oct 2007. I used Chevy rods, stroked the crank 0.100, kept the deck clearance at stock 0.018

The 4 pistons were $277, 4 pins $71, 4 top rings $49, Wiper rings $23, and Oil rings $32.

My pistons are 82.5 mm, a fairly standard size in modern cars. Did that save me money? Or did I get cheaper rings? Or was i just lucky and caught them in a nicer mood? Jarrid Gross had suggested 82.5 mm pistons instead of some round number overbore as an aid to getting readily available rings. 82.5 mm is 3.248 in or equiv to a 0.037 overbore.

I would suggest that my pistons might be a good "standard" for use with Chevy rods, but everyone has their own ideas regarding stroke or destroke, dished or not, etc.

Tom
 
You must log in or register to reply here.
Top