79 F32 Props

TabomaToo · Post by **TabomaToo** » Tue Nov 17, 2009 3:54 pm

Good day all this is my first post on this site but at one time was very active on another Trojan Web site originating here in Canada. I haven't been on in some time and realize the old site is now gone. I knew the chap that set it up but have not had contact with him in a few years.

Here is my question my 79 F32 FBS has Chevy 327/223 engines. I don't have the spec on the trannies with me now but I can get the info later. I cannot get the engines over 3100 to 3200 RPM yet my GPS says I am running 39 KLM can't remember the Kt conversion but this is flat out and unless conditions are absolutely perfect the boat feels like it is not at full potential and sluggish.

Now to clarify I do not perceive this vessel to be a high speed racer by any stretch of the imagination but once or twice a season I like to give it a healthy run. Secondly when out in big water I have trouble getting up and over or staying with big water 4, 5, 6, footers and on occasion more. Again the boat feels sluggish or underpowered or very little power. But still showing 3100-3200 RPM. The power band seems very low with good up and out of the water good planing but that last bit of go doesn't seem to be their. Is it the engines being tired (1500 hrs each) or wrong props or am I looking for something that simply isn't or shouldn't be there?????

For the record

engine compression across the board 110 to 118>>>> told this is good
trannies good no problems
shafts and props rudders perfect

I do not know of anything mechanical that would produce this sluggish high end feeling and lack of performance.

I believe the props to be original and standard but have never found out what STANDARD is >>>>>can anyone provide me with what the spec for this power setup is supposed to be?

For anyone wishing to help I appreciate the effort and in return for whomever wants it ......I Glass blasted my hull 4 years ago and removed 25 years of build up antifouling and then applied Interlux Barrier Coat 2000 with outstanding results and would gladly share pictures and info on that project.

And by the way for all you people concerned about being on the hard stuff for the winter i have been out for over a month and frankly after the crappy sumer up here in Ontario glad to be out and looking for a decent summer starting in April 2010

Murph

jav · Post by **jav** » Tue Nov 17, 2009 4:46 pm

Murph-

39 KPH is around 24 MPH or 21 knots. A little low if you truely have 440 HP unless- the boat is really heavy or the bottom is not clean.

To answer your question- factory propping for 225hp with 1.5 gears was 16x16 3 blade with super cupping. This was probably too much pitch for anything but a new, lightly loaded boat. Add bottom paint and gear- 16x15 worked better.

A few things strike me from your post.

1) WOT RPM too low- engines should see 4000 RPM- ideally 4400. This could be caused by: wrong prop pitch for the gear ratio, really dirty bottom, really heavy boat or weak engines.

2) Compression numbers seem even enough but rather low. I would think a healthy 327 should register 130-150 PSI if checked correctly. Could be faulty readings, worn rings, scored cylinders or bad valves.

3) It could be that a pitch or gear problem is keeping the engines from reaching their full power potential... in essence "lugging" the engines. I can see the boat feeling sluggish if run this way. It would be nice to know the gear ratio and prop pitch. Also- how was the bottom when the run was conducted?

ready123 · Post by **ready123** » Tue Nov 17, 2009 6:55 pm

Murph,
Have you checked that you are getting full throttle at the carbs? Could the throttle cables be maladjusted.
That speed suggests you might have 16x16 props.
As you are on the hard you should be able to check the stamping on them.
I run about 21 mph (33 kph) at 3200 rpm with my 17x14 - 4 blades and a normal load.
I have a set of 16x15 three blades as spares... so if your's are higher pitched you are free to test mine in the spring.

I would expect it to be more than just over pitched props to keep you down that low (3,200 rpm) unless your boat is very heavy.... check to make sure you get full throttle at the carbs.

prowlersfish · Post by **prowlersfish** » Tue Nov 17, 2009 8:14 pm

all good advice above , however Is the bottom clean ? props rudders shafts clean ? thats the first thing , make sure your tachs are Right . you can waste a lot of money trying to prop a boat when the tachs are wrong

one last thing you have Chevy 327 s ? are you sure ? the last year made is 1969 , I would think you would have 305 (5.0) or 350 (5.7) engines if runing chevys

Paul · Post by **Paul** » Wed Nov 18, 2009 10:14 am

Hi Murph,

Good to hear from you again. I remember you from the old TBOA site a few years back. You'll find that there are several F-32 owners on this site that will be willing to help you out.

The 327s seem to be an odd engine to find in a late 70's boat. They are a great engine none the less. I used to have one in a '73 Vega for the drag strip. I found that although it was a little shy on torque, it made up for it in horsepower. WOT of 3100-3200 rpm however sounds quite low for these engines in a marine application. I agree with Jav that you should be closer to 4400 rpm. If you find that you have the correct props, the next thing I would check is that the centrifugal advance in the distributors are moving freely and that the timing is set correctly.

Hope this helps,

Keep us posted

TabomaToo · Post by **TabomaToo** » Wed Nov 18, 2009 1:46 pm

WoWa thanks for the speedy response to all..... this is great

To answer a few questions Hull is as clean and as smooth as a babies butt one single coat of anti fouling over barrier coat>>>> dont think that is the issue

My error the engines are not 327/223 they are in fact 305/223 Chevy's

The tacks and distributor were checked out in 2008 and all seemed fine then but will look at this again in the spring

My understanding is as you all have advised 4200 to 4400 rpm is more like the performance that we should be reading and lastly the boat is not overly heavy ...no generator ...no saddle tanks and normal waste and water holding...beer might run the numbers up on occasion but thats all.

Going up to the marina to have a quick look this weekend and will get existing prop sizes and transmission info

Great help people thank you I will be back a in a couple of days

Thanks again

g36 · Post by **g36** » Wed Nov 18, 2009 2:10 pm

have you made sure that you re getting full advance on the timing? advance springs or stuck advance weights?

captainmaniac · Post by **captainmaniac** » Thu Nov 19, 2009 11:02 am

Had tried to post this yesterday but post failed for some reason... A couple of years back I had a problem with one engine refusing to rev over 3200 rpm. Another 'symptom' - throttles way out of whack. To get that engine speed I had that engine's throttle fully forward, while the other engine was only at partially open. Turned out to be a messed up distributor - only advancing 2-3 degrees under full load. Once I swapped it out for a newly rebuilt replacement, I got full engine speed back again, and the throttles became synchronized again.