Volga Hydrofoils Messageboard

Hi,

I have put my boat to water and am testing it since 6 weeks. Unfortunately the test runs were not very satisfactory, as we found ourselves lurking around with approx. 10 knots at max 2600 rpm.

During the rebuilding of the boat, we made following changes:
Hull:
- we added a stainless steel patform for waterskiing purposes at the back, weight approx. 50 kg.
- we added an anchoring hide-away (Chrome box) on the bow, weight with anchor 15 kg.
- we made a wooden deck with a new wooden hood for engine compartment, and a box or convertible seat extra weight approx 100 kgs.
- we changed the seats from alumininium to wood, extra weight approx. 80 kg.
- we changed the aluminium tent pipes with stainless steel, extra weight ca 10 kg
- we changed the dasboard, extra weight approx. 15 kg.
- we changed from single big battery to double small batteries, extra weight approx 20 kg
Total: approx 290 kg.

Engine:
- we reconditioned the engine full with replacing new liners and new pistons, gasket, pump and reconditioned coolers.
- the engine block was machined down at the vicinity of the cylinder head by 1 - 2 mm, which resulted in a higher
compression of 7,6 bar (The old compression per book is 6,9 bar). Estimated power increase 5%
- As 76 Octane Gasoline is not available, we use 95 Octan. Estimated power increase 10%
- We exchanged the old distributor with a new high voltage one, which sparks with 35.000 V instead of 3.000 V. Resulting in better
ignition and better carburation of the fuel. Estimated power increase 10%
We could not measure the power increase, but estimate that we have been able to increase the power to 112 HP at 2800 rpm.

Wings:
Where cleaned and polished

Propeller:
Was cleaned and polished. The workshop has ballanced propeller and corrected some bends on the blades (?) according to the blade
which seemed to be most untouched.

Result:
The extra weight of approx. 290 - 300 kg is an issue, however if you consider that we drove only with 2 persons on board, it should be like as if 6 would be on board. During the test, we had also only a 1/4 tank full only. The engine was unable to rev-up to 2800 rpm and stayed at approx. 2600 rpm max. The speed couln't be measured but was estimated with 10 - 13 knots only. The spark plugs taken out
show, medium brownish color, which should indicate a good carburation. Buy best cheap Rolex Replica watches online, top swiss watches.

Possible mistakes:
- The extra weight is too much and the boat reacts very sensitive on this! (But how come, that you can see a boat with
original configuration running with 6 persons (480 kg) onboard approx 30 kn? We have +300 kg and 2 persons (+180 kg)
which is same?)
- The propeller was not put in original condition and the pitch was increased by the workshop (?).
Does anybody know the original propeller pitch of the GAZ 53L, V8 4,3liter engine? So we can remeasure it,
before trying to give it a lower pitch?

Best regards,

Our previous tests on the boat were lacking accuracy, as the teleflex stuff was unable to deliver accurate data. The speedometer did not show the boat speed as the pick-up was clogged with marine growth. The revometer showed 1200 rpm when engine was switched off! So there was no reliable data to hold-on.

We downloaded Navionics App on I-phone for the speed and used a Jaguar revometer on the engine to eliminate the question marks.

We made another test run of the boat. We checked the vacuum created by the of suction in the carburator and which affects the membrane on the distributor creating the advance firing at higher rpm during load. We found the hose being cracked and leaking. We shortened it and tested the distributor. Happily we believed to had solved the problem. The lacking power at higher revs should be reason for the engine not willing to rev up to 3200 rpm and the advance regulation should help there.

With a calibrated Jaguar revometer we measured now 3000 rpm engine speed while the boat achieved 11,5 knots of maximum speed. The boat speed should therefor not (only) be related on the engine rpm. We obviously do not reach the the speed of approx 27 knots (55 km/h) at 3000 rpm.

As per previous calculations on weight I doubt that (only) the additional stuff is reason for the low performance. The engine couldn't rev up to 3200 rpm. Why? Maybe the resistance is too high and the engine torque too low. I suppose the engine is really not strong enough, even after all modernisations we made for powering it up, the performance is sobbering.

So after all tests we again do not understand the low performance. It gives so far no sense!

We will make another try by taking away wooden elements like hood, parts of the platform, seats, anchor and other stuff. I suppose the boat will get 100 kg lighter. Let us see what will happen then.

my volga 6.2 l diisel v8 at 2000rpm 325 n-m taks 8 persons 43 knots 4600rpm 15/21p marine prop +engin is 300-400kg.with 22p and 23p runs good 2 , 24p is to much.....on 3000rpm is 25knots
i cnow that gaz 53 is engin at 2500rpm 295n-m they are like same engins.it have to run ,thinking u have bad engin or gearbox taks to much power of.and gaz 53 can ran 6000rpm

Dear Fox,

I tried to find in the internet a torque/rpm diagram of the GAZ 53L engine but could not find.
The engine has been produced over many years and probably was upgraded several times, too.

Known versions to me are:
1965 model, engine type GAZ53L on the Test Report indicated with 70 HP (Propeller power)
The indicated engine power is 72 HP at 2800 rpm or 76 HP at 3200 rpm.

1984 model, engine type GAZ53L on my boat indicates 90 HP (Л.C.) at 2800 rpm. For this I calculated 226 Nm
(at 2500 rpm you say even 295 Nm?). This one was only the original engine with old carburator and old distributor.

The same engine was upgraded now GAZ53L
Electronic high voltage ignition
New carburator
Modified compression from 6,9 to 7,5 bar
95 oktan instead of 76 oktan gasoline

Do you or anybody else have any idea, what the power now could be? I estimated 20% more.
We eliminated the rev-limiter, I do not understand that the engine does not rev over 2800 rpm!

i cnow a man for this they use that engin gaz53 on race http://www.youtube.com/watch?v=Zgn-rQ7EGKA thees engins go 6000rpms i will ask him a think he have some engins what have all done to run like that.there is rules everithin have to bee originale no turbos no kompresors all original........... what they do with engin i dont know jet

look that http://www.youtube.com/watch?v=Bw_fNvTp ... ure=g-vrec

he say the originale divider is bad one thy use that device from bmw v8 and carburetor is with 4 holes from bmw has well, he say you have divider electric circuit not good or somthing,,,,,,,,,, that engin will run( if thees things working good)