• 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.

1592 for Racing

bernd_st

Bronze Level Sponsor
Think we were talking about flat top pistons readily available from the market for a Rootes engine application. There is no doubt that forged and lighter pistons requiring heavy modifications could be a better match to full race requirements. For those, however desiring fast road reliable engines w/o big mods the JP flat tops could be interesting though. That's why we have investigated about them. By the way, even the Holbay +120 HP engines used cast flat tops. Will crosscheck your weight statement for 0.040" STD piston . Think they are definitely heavier - all in - than the JP's...
 
Last edited:

spmdr

Diamond Level Sponsor
Jerry, It looks like you are close to building an engine or 2, tell us what you have decided and what performance you hope for.

DW
 

spmdr

Diamond Level Sponsor
At this point, I have almost talked myself into building a 1592 engine.

However, it would displace "at least" 1725cc.

I already have the rods, and pistons are on order.

But, when I ordered the pistons, I planned to build a 1725 with a stock stroke.

So to easily use the pistons, I need to grind the 1592 crank to a 1725, 3.250" stroke.

Fortunately, there is JUST enough meat in the crank to do that with the smaller

big end of the aftermarket rods I have.


Seeing I need to custom grind the crank to use the rods I have, picking a longer stroke

is a no cost benefit.

DW
 

spmdr

Diamond Level Sponsor
The pistons are -.005 from nominal Zero Deck.

We'll see where I end up with the short block build(s).

I usually run Zero Deck clearance.
 

spmdr

Diamond Level Sponsor
Progress on a 1592 engine for the Weekend racer

is going slowly.

But, it is progressing!

Currently working on the oil pan:


I am contemplating mods for the bottom end.

at this point, the minimum is planned to be

some support for the main caps.

I would love to fit a full main cap girdle,

but with the front cap bolts outside the oil

pan, it's a Real challenge....

And I don't know if Bigger Main cap bolts are practical.

I will most likely use a 1725 oil pump.

DW
 
Last edited:

jumpinjan

Bronze Level Sponsor
Seriously, how much horsepower do you think a 1600 will give you, by thinking you need to fit a full main cap girdle?
Jan
 

spmdr

Diamond Level Sponsor
Jan, My goal is 150 HP.

I expect to go to 7000-7500 + RPM to get there.


With the current mix of planned parts,

I will be grinding the crank down a fair amount.

to fit the smaller rod journal sizes.

And the crank will be more flexible.

To hopefully keep the bottom end together,

at 8000 RPMs, I think the main caps are likely

the weakest part of the bottom end.

BUT, the Block main webs are not as beefy as I would

like to see...

I have yet to look over the different years of block

castings to see if there are any differences.

Also, I would point out, It seems few have gone

as far down this road of high RPM 1600(+)s

...and are willing to talk about it...

SO, I'm just giving it my best shot.

DW
 
Last edited:

jdoclogan

Platinum Level Sponsor
I have not designed my engine builds for the high RPMs you are reaching for DW. Jerry Titus and Doanne Spencer dialed their 1592 builds into a 6000 -6500 rpm reliability range. Above that RPM range they found engine failures occurring. Of course they were dealing with component/material composition and design limits from their time period. It will be interesting to see what the dyno shows for my builds. I did use some of the increased stroke/rod sizing concepts you shared with me. However, I emphasized intake/exhaust flow as the magic wand for increased HP. Head mods sporting twin side draft Webers and the 4 into 1 header I designed. Along with lightened flywheel/pressure plate. My machinist did a full circumference groove to the cam journal for continuous oil flow to the rocker system. Increasing the oil pan size seems reasonable. But, while reading your statement I was thinking like Michael. Increased width with wing capacity not taller because of ground clearance. I would have to get everything up on my lift to mull over the pan modification.

All this being said. I know and have experienced the exhilarating power (claimed to be 150HP) of a Chris Draycott built racing Alpine engine. I was riding shotgun in Glenn Brakenridge's vintage Rally Harrington Le Mans at the Prescott Hill Climb last year. I'm not certain if this is a Draycott 1592 or 1725. Regardless, I felt significant G-forces (unlike any other Alpine experience) as my brain shifted to the back of my head upon launching from the start. I will be over to England in a couple weeks for the Silverstone Classics and the Goodwood Revival. I'm going to try and visit Draycott's shop. Not just talk to Chris like I did last year during a track day at Donington Park Circuit.
 

spmdr

Diamond Level Sponsor
Jan, Never?

Tell us what you realty think, don't hold back. ... :)


But, please elaborate on what you think are the limits

of an Alpine engine ( less than 1800cc ), power wise.

What is a Max HP number at what RPM?

DW
 

alpine_64

Donation Time
Huh? You will NEVER get there.
Jan
Jan never get to the HP or the RPM?

There is an Alpine that runs in historic production class in Australia that is a 1592 at the legal 1633 max overbore. It does 7600 and on modified Zeniths put down 122bhp at the wheels and when It changed class and switched to DCOE it managed to get 138bhp to the wheels.... Which would certainly be around 150 crank HP
 
Top