Ski boat project questions

Discussion in 'Powerboats' started by aussiebushman, Sep 22, 2012.

  1. tunnels

    tunnels Previous Member

    Lots XJS got a transplant with a v8 350 chev motor ?? in New Zealand because the V12 motors are so exspensive to fix and a chev dropped straight in the hole almost and the bell housing and clutch were compatable so i was told .
    We did have some other jag models with v12 as well . to big ! nice cars but not me !!
    The wee MG sounds more my size !!

    I used to be int cars when i was young but its just a mode of transport now and has little interest .
    My 2.5 Mazda V6 is quite enough for me !goes well is 100 % reliable and is not to hard on petrol pulls my boat with ease and is comfortable . Can load up the 12 cd stacker with all my favorite music and drive for miles :D:p:p
  2. Frosty

    Frosty Previous Member

    The early ones were 4 strombergs, The other jags you mention were the XJ12 or the Daimler double 6. They did 12 miles to the gall no matter what you did.

    I did mostly E type V 12 work. I cant say I liked them.

    In 76 they went fuel injection. I think it was Bosch K or maybe J
  3. tunnels

    tunnels Previous Member

    those were the days

    Long time ago i use ti race a old 100 prefect and i had a matche pair of mini cooper SU carbs but could never quite get the right needles of them , had one pair for wet weather and another pair for dry weather .
    Some where buried in my boxes of old books are all the information sheets on su carbs a little while later was the zenith stromberg and i have a complete list of crbs and servicing data and needles etc as well i sold the 100E and bought a 1340 cc 315 consul , i did a complete reco from ened to end and converted it to floor change , a friend had a 1500 cc gt cortina with a 5 bearing crank and over a 11 miles i could pass him and get a good mile ahead of him by the time we got to the other end !!
    free flow capri exhaust , Cortina GT twin choke webber carb with gt cam and i had the head ported and polished and big valves with off set valve guides , double valve strings and i made my own exhaust system with a cooper muffler . my wife use to drive the car to do the shopping and was just like a standard car !! on a long trip it did 50 miles to the gallon
    it could wind right off the clock with a 4.125 diff . it was a really nice car to drive and i used to blow off humber 80s and 90 for breakfast would even give a sunbeam rapier a good run to 80 mph after that he just walked away . my 1340 cc with a 3 bearing crank would rev to 9500 rpm no problems . :):D:p:p.
  4. Frosty

    Frosty Previous Member

    100E is a side valve --is this a trick question ? there would be only one manufacturer of a manifold for a single 1 1/4 Su and that would be Hydroplane.

    If you were trying to run A 100E on twin cooper 1 1/2 SU then I think I know your problem its called CFM deficiency.
  5. tunnels

    tunnels Previous Member

    yip its all coming back to me !!

    The coopers only had 1 1/4 carbs on the early ones but they had left and righ bowls and all the linkages went to the middle so to install was reall simple .had chrome pancake aircleaners with 2 3inch long bell mouthed velocity tubes fitted inside that made then run much better if you had a lumpy cam shaft with lots overlap . used to spit back out the carburator and pertol every where .
    Side valve yes 1172 cc the trick as to relieve the block 1/8 between the piston and the valves . they only had two intake ports but could make then oval in shape and split the pipe and insert a wedge shape bit of steel and weld it all then smooth and polish inside and out or it awas possible to drill the block on a mill and insert 4 pipes and fit 4 amal motor bike carbs . remember the 105e overhead valve hadnt hit the market when i first stared work . the balance pipe between the two manifolds has to be 3/8 inside dia if you used 1/2 it up set the tune to much so you shut one carb completely and just idled on one carb
    The 105e 997 cc was the fore runner of the 109e 1340 cc that had a better block and that block would take 997 cc 1198cc 1340 cc just by changing the crankshaft and conrods . for nz bought out the 107E which was the old prefect but with the anglea motor and 4 speed gear box The 1498 cc was a 5 bearing block but same bore size just the block was higher and a longer stroke . A brand new cortina 1500 could pull 95 mph on the speedo
    Then the ford compan has a long build motor that was a 1500 cc was really cheap and could do a motor change in one day no sweat ,drive in with a 997cc and drive out with 1500 cc same day with just a few minor changes like the springs in the clutch pressure plate was just one thing i did of my own !! i was well schooled up on all this stuff beause i worked in the spare parts department and had access to racing gear listings from ford in England .:rolleyes:;):cool::
  6. Frosty

    Frosty Previous Member

    Tuning a 100E or the earlier E93a would be like errr putting brake shute on a transit van.

    Or fitting a 11/2 exhaust on a wheel barrow,---or ............

    I know I know --fitting carbon fibre brake discs to a Fiat 500.

    Oh by the way 100E was 998cc,---no point in skimming the head is there. Mind you they were not flat heads but bath tubs and skimming the heads was a waste of time and reduced swept volume.

    They fitted loads of 100E them in the Albatross ski boat of the 60's.
  7. tunnels

    tunnels Previous Member

    E93a and the 100E were 1172 cc yes i had a E93a on my small boat it had 2 E93A carbs down draughts planed head , and a very light flywheel with the ring gear for the starter, 12 volt on a 6 volt starter ,man it used to start easy . I even tried a stromberg 97 ford v8 carb and that was cool ! the free flow exhaust used to glow red hot at night coming home down the lake after a days sking
    The 105E ANGLIA was 997 cc the standard cortina was 1198 cc the cortina deluxe was 1498cc also the cortina Gt but it had a twin choke webber and a differant cam and a row of gauges across the top of the dash in the cenre
    the cortina lotus with a single row chain and twin cam was 1498 cc as well ,when thet were racing at around 7000rpms the timing chain used to make a loud noise and we always used to like to hear it !! later the BDA with belt drive cam appeared and it was 1600 cc not popular and not very may ever hit nz shores .The genuine mk1 lotus would take the 3litre v6 zephyr engine and that was an really nice combinationand went like a cut cat !!
    my friend had a 1965 fairlane with a 427 chev and that was his dream car .
    Damn this really brings back some memories !! mk111 zehpyr with triple 1 3/4 strombergs and a zodiac head ( had big ports and bigger intake valves ) tuned twin exstractors and twin exhaust all way to the back with twin cooper mufflers ,used to carry 2 bags of sand in the boot over the diff arch to give it traction . Those were the day !! we were living the good life !!young and exciting !
    Yes i had a fiat 500 and we looked seriously at fitting a subaru powertrain in one . it had already been done and was a leathal roller skate on the road man it could go but couldnt stop it !!
  8. tunnels

    tunnels Previous Member

    sorry for all that about motor cars lets get back to boats !
    A good sized underfloor tank will do wonders for trim and getting weight down low !!Like i already wrote boats sitting for periods of time with fuel not being used is not good so need a way to be able to pump all the fuel out like as in total to stop condensation and what ever else tanks get inside when left with fuel in them !!.
    In the boat i have now i intend to make a floor tank !! the top of the tank will actually form the top of the floor to walk on . Will make all out of fibreglass painted inside apart fron a 50mm wide strip right at the back of the tank in the middle so i can actually see the fuel level inside the tank !! like a sight glass !! The floor immediatly behind the tank will be 2 x 600 mm long lift outs one to see the end of the tank and to serve as storage compartments for ropes etc etc ,the tank filler and vent will be at the front and the deck filler just in front of the windscreen off to one side same side at the car filler !! make sense ??
    The tank vent right at the top of the side screen facing rear wards !!. over the years have made lots of glass fuel tanks mainly in big boats ! theres vinylester resins and special paints that are fuel resistant to use for the inside layers and and just finish the outside with standard ve resins and good glass . the top will have a 12mm Balsa core with a 50mm wide flange round the outside for the top and bottom to be joined with ve resin paste .
    In nz we can get a product called "exsplosafe" its an aluminium looks like a giant pot scrubber and you place that inside the fuel tank and it dosent need baffles plus its exsplosive safe its been round for years and was used quite a bit in the 1980s mainly for petrol tanks specially underfloor in boats in nz ! its so fine and displaces only a tiny amount of fuel even with the tank completely filled with it !! The first time i saw it was at a boat show and a can with petrol had a flame burning at the mouth of the container , normally an absolutely impossible situation . the petrol slosh dampening and no need for baffles is me ,plus the safety factor as well .
    My boat is my hobby! the cost is a factor but the pleasure and the satisfaction of making it better than it ever was and its unequeness gives me great pleasure. i have made it to how i want it and everything is my own ideas and not been copied from anyone else . everything works and works well . i have done stage one and soon i will remove the motor and roll it on its side against a solid wall and do stage two ! subtle changes to the bottom that would make some people sit up and take notice . the hull is a very early model of that particular design and has no strakes so i have just 2 wide strakes to be fitted !!,The small external keel will form the back bone to increasing the vee a little more and making for a softer ride so i can cruise at a faster speed in the chop . Will introduce a little rocker into the bottom as well . Its where all these things are situated and converge thats the key to its success !. front will get a sharper step so it cuts into the water . the strakes are there to lift the hull at speed so they will be wide and concaves slightly and not just there to difflect water !
    Strakes are so miss understood and over time i have exsperimented with small boats ,they can and do increase lift and added Manoeuvrability at speed has left some die hards with there mouths open and shaking there heads how did you do that ??
    Have a nice day !:D:p.

    Just found a foam that does the same job or maybe even better !
  9. Frosty

    Frosty Previous Member

    I never messed with cars like that I worked on Jags RR Bentley Alvis Astons etc etc . My daily run about was my love of all cars the Jenson Interceptor, I had 2 at once a 440 ci and a 383.

    The 440 would often pull of the port side engine mounting if I booted it in 2nd gear--something I could never resist from doing.

    100E fiat 500 sorry I know very little of such motors only there mere existence.
  10. aussiebushman
    Joined: Oct 2009
    Posts: 283
    Likes: 33, Points: 28, Legacy Rep: 132
    Location: Taralga NSW

    aussiebushman Innovator

    Good advice about the fuel tank and "exsplosafe" Tunnels.

    A good sized underfloor tank will do wonders for trim and getting weight down low​

    The floor immediately behind the tank will be 2 x 600 mm long lift outs one to see the end of the tank and to serve as storage compartments for ropes etc etc ,the tank filler and vent will be at the front and the deck filler just in front of the windscreen off to one side​

    Not so sure about the external strakes yet. I brought the hull here to the farm yesterday and will get the pictures and dimensions for further advice. I first have to work out the best way to suspend the hull from the shed roof so I can remove the (trimaran) trailer that will eventually be replaced with something more suitable for this hull. I think I have found an old Deltacraft trailer that will be ideal after a few minor mods.


  11. tunnels

    tunnels Previous Member

    Its geting exciting !!!

    For the floors one company we used a Z shaped aluminium section and placed it along the edge of the floors where the stringer is . and that supported the lift outs .
    Think seriously where you going to place your battery .It needs to be up off the floor is possible in a place thats easy accessable but where it wont get water splashed or dripped on it at any time . The closer to the motor the better so you can keep the cables short for the starter and power supply etc .

    Are you looking at fitting strakes ?? strakes are a mystery to most people i know . they have the impression they are just spray rails that produce a small amount of lift . Done the way i do them can make a hull sit flatter and more stable in the water once you get a bit of speed up !!and because they lift the hull it helps reduce wetted area .
    I had a oldish boat before the one i have now and the strakes went all the way to the bow !! damn it was a hard riding boat !!,the harbour chop was bad enough but get iinto some bigger waves as well as chop it was a shocker it thumped real bad i was glad when i had had enough and sold it .
    Small narrow trakes are usless unless !!! If you intend to make them work and lift like they should be used for !.
    I am not in favor of multiple strakes all over the bottom . Just two !! one each side is all thats needed . After i see some pictures and get sizes etc i will tell you what i would do !! You have a big motor hanging on the back !! maybe even on a bracket so the strakes will need to be wide and i mean wide !! not sissy little things !!. I always have a 2 degree turndown all there full length and put a very slight concave it the surface . The widest part only goes for a distance of say 1.8 to 2.0 meters and then tappers out to nothing and neve gets to the water entry /bow end of the hull ! .
    As i say need to see pictures of the bottom , transom and a chine level side photo with the bow shape /angle etc . the bottom of the hull also need to see if it has any rocker or hook . Do you understand the diferance between the two ??
    They both rocker and hook can have there uses . Some really fast boats have hook !!,near the back and makes them get up on the plane really fast and the hull just rides on the last 300 mm to 400 mm of the hull at speed when trimmed out with the air supporting the hull and thats a reall hard act to follow !! .
    Rocker can have a simular effect as well but its the placement of the high point of the rocker thats very important . For race boats that need to turn quickly and not have to touch the trim button ,rocker done properly is just the bees knees the moment you turn the wheel the outboard lifts the back of the hull as it starts to slip sideways this making the nose go down and dig slightly and round you go !!, pull the wheel straight again and all goes back to normal !!,back down, nose up, and flying . Thats just a simplified discription of what each one can be used for .
    Something else is the hull shape along the vee of the keel . its better not to have a actual keel that sticks down ! but if the hull has one then its need to finish at least 1.800 mmm from the transom or you will get a airated prop when you start to get into a turn . A nice sharp Vee is better all the way from the stem to about a cople of metres from the transom . The sharp vee make the hull track dead straight and not want to wander off one side or the other . the vee does not want to have any round at all not even the smallest bit . Having worked on raceboats i had these things ground into me from day one the importance of it all !!
    The fine tuning of each and every part makes for a boat thats totally predictable and absolutly magic to drive .
    Theres nothing worse than a boat that does silly things for seemingly for no reason . Knowing and completely understanding what does what then you can fix those problems !!
  12. aussiebushman
    Joined: Oct 2009
    Posts: 283
    Likes: 33, Points: 28, Legacy Rep: 132
    Location: Taralga NSW

    aussiebushman Innovator

    The hull is now off the (interim) trailer and suspended from the shed roof beams, giving access to the underside where some minor scrapes incurred in transit need to be repaired - no big deal. All critical measurements have been taken.

    Here are pictures providing a better idea of the hull shape and condition. (before anyone screams, it was exactly like this when I got it). There is one bulkhead forward where the deck over it was removed. I'll bond in a couple of new deck beams and replace the deck panel (supplied) The next bulkhead about 1 metre back from the stem has been removed completely so this too will get new deck beams once I work out the best fore and aft position for the dashboard and seats.

    Along each side of the hull, there are what look like flotation chambers. These need minor repair to make them airtight. They run aft to about 600 mm from the transom so this is where the splash well will be constructed. Between these will go the fuel tank and battery compartment and I take your point about using the position of these to get the fwd/aft trim right.

    Regarding external strakes, your advice is appreciated, but I'm inclined to leave the hull as built - you can see from the fwd view it already has small strakes moulded in and I'll have plenty to do without adding complications.

    I'll provide drawings once I get Freeship sorted


    Attached Files:

    1 person likes this.
  13. tunnels

    tunnels Previous Member

    yahoo !!

    So you are now the proud father of a never ending project !!oops boat !!
    Shallow vee so is not a sea boat ,also a long racked back stem deffinitly not a sea boat !! but all in all its pretty cool and a really good start !!
    The bouyancy chambers !!! , dont seal them up 100% or they could go pop or even boom some time !! Trick is to use a copper tube 1/4 "and use it as a breather and also to keep the chambers dry !! need to have one end right down in the lowest place of the chamber pass it inside 50mm seal and and glass it on and run tube up the the hull and turn at the chine and the other end under the side deck with a turn down !!
    The air can exspand and contract like nature intended and each time it exspands the pressure forces the water out and keeps the chamber dry and non smelly because it breaths all the time !! Clever aah !!:idea:
    The splash well i wouldnt touch for quite some time !! If you intend to fit a bracket then the motor will sit back aways and becasue its a 25 inch leg its high and you could almost get away without any splashwell at all just a shallow hollow in the aft deck for when the motor if fully tilted up with clearance of coarse !! The aft deck when you make it becomes a very structual part of your transom so you could need a couple of strong knees down onto the sides of those stringers and bolted through!
    Dosent look like its ever been a outboard boat so the transom may not be very thick !! so once you find out what its made from and how thick you may have to rebuild over the top of and thicken it up considerably !!
    Any way good luck !!:D:p
  14. aussiebushman
    Joined: Oct 2009
    Posts: 283
    Likes: 33, Points: 28, Legacy Rep: 132
    Location: Taralga NSW

    aussiebushman Innovator

    Propulsion & rudder systems

    More silly questions - Now the hull is suspended from the shed beams, it is possible to inspect the underside of the hull, also to try to work out the propulsion and steering:

    • Despite what I was told, the original engine must have been an outboard as there is no evidence of a shaft. The transom is only about 12 mm thick so as recommended by several of you, it will need thickening to 50 mm and with heavy knees to take the thrust of a 150 HP outboard. That will be reasonably simple for me to do
    • The heavy plate is obviously a cavitation plate and it bolts to the underside of the hull through the existing holes (with stays from the transom). The stupid questions are:
    a)do I need to retain the cavitation plate or is the one on the outboard sufficient? If retained, is it likely to interfere with the outboard leg?

    b) will I still need to retain the integrated rudder and lock the outboard fore and aft OR can I steer with the outboard using the remote controls?

    Be kindly with your answers please. Remember I'm a just a simple sailor with virtually no experience of powerboats


    Attached Files:

  15. tunnels

    tunnels Previous Member

    She has been a inboard !! that plate with the rudder attached the slote hole in the top of the transom is where the arm went inside the hull . If you get and have a look see in the corners of the topsides meet the transom there possibly holes where rope pulley blocks could have been fixed or theres blocks of wood stuck there where the blocks were !
    There could have been cable steering going down each side of the hull so some where near where the dash and steering were positioned there could be signs of more blocks or screw or bolt holes towards the front some where .
    No i would not fit the plate at all its for inboard not outboard and will serve no usefull purpose at all !!so scarp it !!.
    Like i said before you have to make up your mind very early on if you going to fit a bracket or not !!!
    The 12mm thick transom means inboard as well . some where there has been a hole for where the shaft had been but could have been all glassed over and even painted over !!. There might be better evidance of its location inside rather than outside . The prop shaft would also have had a strut so there could be signs of a block located inside about 300mm long x 150mm wide some place near the back inside could be up to 400 mm forward of the transom Again if its not there then the holes for bolts etc would have been glassed over .
    Would be good to find and locate but its not that important !.
    Is there any places where there holes on the stringers where engine mounts
    could have been ??
    Just hope its been glassed over properly . The transom will be glass on the outside then 12mm plywood and glassed on the inside !! what you have to determine is the ply still sound or is it rotted !!
    Theres a drain at keel level so get a screw driver and have a dig . if you can push the driver into the wood and its soft then it will be rotted for sure . BUT if it is still hard and solid and dry its just a matter of making another new transom laminating 2 layers of 18 mm or 2 layers of 20 mm !ply together to make up the 30 plus mm thickness you need for the complete new transom thickness then doing a good glass job over the top after its stuck in place .
    keep the photos coming !!!
    i am going to store and highlite ,then print off so i can see more detail !!

    Have you done any fibre glassing before ??
    what resins have you used ??
    epoxy ??
    Polyester ??
    Do you know the differant types of glass that you could be using ??
    What sort of tempratures and humidity do you have now and will be getting in the coming months ahead ?
    sorry for all my questions just need some basic info so we can help you more and better and avoid any possible problems in the future as you progress !! will keep everything basic and simple and explain why where ever possible !!
    Its time for me to go !!:D:p
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.