Need help identifying an HP 40

[Robert Zambelli]

I came across this engine at a swap meet.
Can anyone decipher the markings?

1st photo, bottom of left lug: F51994
2nd photo, side of left hand lug: T.R.# 03 US  .36F
3rd photo, rear of head: 03
The plug appears to be a BUCO 18.

THANKS, Bob Z.

[Randy Cuberly]

Well, Understand I'm not so sure about this but I remember rumors many years ago about someone who converted a number of HP 40 Gold Cup engines to .36 displacement for Slow Rat and Carrier. 

This one obviously would be one intended for Slow Rat because of the lack of a carb.  It would be more telling if a picture could show the inside of the exhaust port and the venturi size!

I have two Gold Cup engines converted for Stunt and they look precisely like this except for the obviously turned sides of the head on your's.  The Gold cup has an all black head instead of just the black top on yours.  The piston and cylinder would also be different on yours although there isn't a lat of size different between a .36 and a .40, as you know!

Again this is a guess based on my Rat Racing days experience of many years ago!

Randy Cuberly

[dennis lipsett]

It could just be an HP 40 Silver Star with a venturi assembly on it. This was the cheaper version of the gold star and didn't have the ball bearing. They were still very good running motors.

[RandySmith]

I came across this engine at a swap meet.
Can anyone decipher the markings?

1st photo, bottom of left lug: F51994
2nd photo, side of left hand lug: T.R.# 03 US  .36F
3rd photo, rear of head: 03
The plug appears to be a BUCO 18.

THANKS, Bob Z.

That is  a  HP 40 Silver Star , it does have  dual ball bearings, and this one has an aftermarket venturi NVA   and  a machined head,  HP did have a fin less  black head they used on some Silver Stars

The  HP 40 Gold Cup was  back body with a  Gold Anodized  FINNED  head

Randy

[Mike Greb]

if this is a front intake .36 conversion that is a new one to me.    The 35 conversions that ran in slow rat were the rear intake motors that had a st29x rear intake crank to destroke the motor to about a .34 or so.

[Brett Buck]

That is  a  HP 40 Silver Star , it does have  dual ball bearings, and this one has an aftermarket venturi NVA   and  a machined head,  HP did have a fin less  black head they used on some Silver Stars

The  HP 40 Gold Cup was  back body with a  Gold Anodized  FINNED  head

Randy

  It's certainly a Silver Star crankcase/head, but I am curious what is really inside - maybe a custom using a Silver Star cast parts.

    Brett

[Randy Cuberly]

  It's certainly a Silver Star crankcase/head, but I am curious what is really inside - maybe a custom using a Silver Star cast parts.

    Brett

Yes, I'm certainly wrong about it being a "Gold Cup".   Sorry about my "shakey Old memory".   It is most definitely a Silver Star as are both of mine.  However The script on the mounting lug would probably indicate that it was a .36.  The only reason I can think of for converting one to .36 would be for "Slow Rat", "Fast Combat", or "Profile Carrier" with a carb.

I too would be most interested in seeing "inside" this engine.

[Robert Zambelli]

OK, Randy - as soon as I get a chance, I'll take it apart and we'll check it out.
Than, off to the Brodak museum.

Bob Z.

[RandySmith]

You are just not going to know  if its  a  40  or  have  different parts in it until you take apart and measure  it

The numbers  could mean anything

Randy

[M Spencer]

Something written on the PLUG there , in the last shot .

Bit like Checking the VALVE CLEARANCES before you strip a motor . Last Chance to establish what they ARE , for the Cam .

If thats a hard plug , etc etc etc . Part of the picture  .O P S they used to sleeve down to .29 for B team race, in Europe  .
Could be a ringed Alumn. piston . Or Lapped Iron set up ?? .

Incidently all my Silver H P 40 R P R 's ( Rear Intake )  Are SILVER , Twin ball race . The Fined GOLD HEAD is Siver Too .

I think the BLACK ones were some later fancy pants heat dispersal paint .
Four Times the Surface Area . Yoshimura & Wes Cooley Suzuki stuff
from around 78 / 1980 .