the z engine

[fbref5269]

hi all,

i've been fortunate enough to pick up some quincy z engines from francis latta, larry latta's widow. i've taken some pictures since i've not seen too many of them posted. the pictures are of a z 125, z175, z250 and 2 z rb. they are soooo much easier to work on than the loopers.

i have some questions for paul.... on the 2 z rb engines i have the carb is facing away from the boat and the plugs are facing inside the boat.... now on the 125, 175 and the 250 the carb is facing inside the boat and the plug is facing the 90 degrees from that. did you and your dad change the engineering on the smaller engines? also what do i need to do to convert one of the rbs to a regular 350 b?

right now the 125 is almost together and when it is i'll post pictures.

frank

[Original Looper 1]

Frank,

As to what appears to be the power heads turned around on the RB engines, that was a deliberate evolution. We started with the Z pro B before the RB's, M's and the rest of the Z line. My father and I came to those reversed layouts because the pipe designs that worked best on the Z engines made the pipe length too long behind the back of the boat, which meant we had to use an extended length pipe support system, and the extra length pipe supports kept cracking and breaking. When we turned the powerheads around, similar to the FA Konig, it enabled us to use an 8 to 10 inch shorter pipe support bracket. This change gave us considerably less pipe bracket problems.

As to the design of your R&D M engines, when Chris closed down Quincy Welding/Precision Machine permanently in 1984, Jack Kugler & Larry Latta took over the racing program and went on in development. Chris and I were often in contact by phone with both Jack and Larry regarding the evolving development of the Quincy Z engines. As to who takes credit or blame for their performance or lack of from there on out is a good question, and everybody had an opinion. Most people that knew the late Larry Latta, knew that he was very educated and intelligent, but that didn't necessarily translate to water performance and speed on the race course most of the time.

As to converting your RB to a B pro engine -- obviously you would need 2 carbs instead of one and, my guess, 38 mm would be the correct size. The rest you can call me about, you know the number.

I especially like the opposed 2 cylinder A. One wonders how that would perform even today with a first class driver, boat, prop, test time and by someone that would use a clean fuel tank, clean fuel filter and fresh battery.

Frank, take good care of those engines as they are all one of a kind and collectable, historic and very likely still competitive in the right hands.

As to the origin of the name, the Quincy "Z" engine; let's see, we were in Quincy, Illinois, Zak was in Moline and we communicated frequently, starting in 1975 (although few knew that) when Chris and I restarted the Quincy racing engine program. Harry used to visit with Chris and me on many Saturday afternoons. It's truly an amazing story that after all these years, no one seems to have figured it out. Harry contributed to pro outboard racing in many more ways than most of you are aware. Think about that.

Look forward to seeing more photos.

Paul A Christner

[RichardKCMo]

Sounds to me like a non effort on some parts of the organization, at that time anyways, or maybe there wasn't an org., at any rate Dieter didn't have that prob. and we went on and progressed.
RichardKCMo

[Original Looper 1]

Mr. Z's influence traveled far.

[Mark75H]

Paul, I have seen that device before and the other caption implied it belonged to the factory. I'm not surprised to learn it was really a Zak. Originally I thought it was 80 cubic inches ... now that there is info that it was actually raced, I'm more inclined to think 60 cubic inches for an F



What publication is that pic from?

[John (Taylor) Gabrowski]

What a picture of that dual power headed Merc racing engine!

That is what that adapter and coupler here is all about except in this case the Merc engines are one front and one reversed. I can only suppose that was done to fit modified Quincy pipes where the picture must have exhaust blowing out the bottom out of some kind of dump through the base adapter plate for the engines.

Those racers then sure had imaginations they turned into results!