w8ye

My Feedback: (16)

Be careful of the sleeve/piston set that has the marks around the top. It may be a HB rather than a K&B. They look so much alike. Carl gave that one to me.

You can still get carbs from K&B for the RJL

NM2K

My Feedback: (14)

------------


Now that would be very interesting.


Ed Cregger

The moderator corrected a spelling error that existed in the quotation from a previous post of his own. This had nothing to do with anything ED said.

blw

My Feedback: (3)

I looked at all 3 liners and those you sent with the K&B aren't for the HB. I knew which one you were talking about with the marks.

Ed- I'll write him this afternoon and let you know what he says. He usually responds within a day with something always interesting. I'll ask him for what he knows about the HB engine line from that time period too.

crrcboatz

My Feedback: (34)

Jim,
How are you sir! Glad to see you are on here and sharing all that knowledge you too have!! Great guy. Are you back in Ohio now??

I have extra 40 and 61 pdp cylinders. Used but VERY clean if someone needs one. Now pitting a converted k&b to a pdp done by Clarance would not be fair as I bet he does a few extra things other than just putting the pdp mods on them??!!!. I have a cylinder shimed 61 pdp that runs very well. I also have a 40 blitz nib never started. With the increased timing and the pipe sat at say 12 inches a blitz should be a hot potato for sure. Put a blitz up against one of Clarence's engines now that would be ok!

Curt

crrcboatz

My Feedback: (34)

this is not a pdp cylinder, as it doesn't have the pdp slits on both sides machined just outside the exhaust port.

Curt

blw

My Feedback: (3)

Curt,

Thanks for the liner and piston in a round about way to me. I'm going to get that ported by Clarence as a spare, and ask if he will do the HB at the same time.

KLXMASTER14

I had a couple of .61 in the late 70's. They were "customs" from someone back east. I do not know who did the work. They were the PDP version with the higher duration pipe timing much like the "Blitz". They came on the pipe hard, and would turn an 11-7 at around 15k. That is where the problems started. The connecting rod was not up to the job, and the ends would ovalize. The first indication of this condition was very short plug life. Shortly thereafter, the piston would actually contact the head!

You may want to consider propping your engine to keep the RPM down below the ballistic level to assure longer life.

Best regards,
Robert

blw

My Feedback: (3)

I had let this slip my mind for a while, but I wrote Clarence Lee yesterday. He said that he only does the PDP modifications to K&B engines. Thought I would pass this on.

rainedave

My Feedback: (1)

Thanks blw. I'm not going to take my HB apart to look, but do PDP slots have the same timing as the main intake port? Or, are the higher up or lower down on the sleeve?

Thanks,
David

BTerry

My Feedback: (8)

David,

I just might make your day.

I was scanning through some of my old RCM's the other day and ran across the article by Clarence Lee describing the PDP process, February 1976. I just love those old issues, and that one was one of the best! I was nearly 5 when it was delivered to my Dad's house. I still love getting magazines in the mail, but I digress. I will attach the article. The tag line on the index page was"pdp...it out-turns the schneurle's".

Obviously this is no longer true as the newer engines have enormous crankcases to house the large bypass and schneurle ports adjacent the exhaust port, but he does mention an increase in filling due to these ports. The PDP ports appear to be just slightly higher than the intake ports.

I asked Mr Lee about which engine to use for my retrofit Curare (which originally had an HB 61PDP in it) and he said that it was such a powerful engine for its mass that I would be smart to keep it. His K&B Clarence Lee Special 61 will perform just about as well, to expect around 10,500 rpm on a 12x8 APC. More powerful engines (eg Supertigre, Rossi) are far heavier. Incidentally he mentioned the Twister line are being phased out. All remaining engines are old stock from K&B.

Apparently he purchases the raw parts from K&B and performs all the final machining. I want to buy one just as a collector, to purchase a great engine from a legendary designer. It is hard to beat $135 shipped for a special piece of history. Isn't he in his late 80's now?

One more thing, MECOA lists the pistons, rings (I would use Bowmans anyway), and liners for the PDP 61 and the Blitz 61. It might be worth a try to swap out the liner for the Blitz? Does the Blitz require a full pipe, or could a quarter-wave pipe work (eg Nelson ultrathrust, Jett)?

I hope these pics upload.

Take care,

Brett

BTerry

My Feedback: (8)

And Yes, I will reinstall the HB in my Curare.

Don Kabirnov

Hi guys,

I just bought a HB PDP .61, red letters, new in the box, manufactured 5.1980, for the huge price of 190$ without the muffler. It's made in Germany, exept for the pump and carb which are Perry made in USA.

I attach here the most relevant pages of the manual.[img][/img]

Sport_Pilot

It has been a long time since I have seen a cutaway of a Perry Regulator Pump. For those who have claimed that the Perry pump is not regulated, this cutaway proves to me that it is regulated.

buzzard bait

Brett, I'm sorry to hear the Twister is being terminated - any idea why? Jim

Warjet

My Feedback: (327)

I opened one of engine storage containers to get an inventory, and saw my collection of HB engines, from the .21 PDP, .21 grand Prix, 40's, 1 50, and several .61's. Some of the PDP's have red letters stamped on the mount, others are black. All have black heads. Does anyone remember which is the stock PDP and which is the Blitz model? Thanks!

NM2K

My Feedback: (14)

I was always under the impression that the red lettered PDP HB engines were the "stock" ones, i.e., no black cylinder head, but I'm far from being expert on the subject.

I finally did buy an HB .50 some years ago, after hearing about them for many years. Haven't ran it as yet. It needs a good antifreeze bath and new bearings before running.


Ed Cregger

Broken Wings

My Feedback: (20)

The ones with the Black heads are "Blitz" models. They have a very thin conventional cast iron ring and a chrome cylinder sleeve.

The PDP Regular head with Black letters are late models

The PDP Regular head with Red letters are early models.

Regular, both red and black letter PDP models have Dykes rings

Warjet

My Feedback: (327)

Thanks folks! Appreciate the great info!