Boingk

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About Boingk

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    Newbie

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  • Gender
    Male
  • Location
    Outback NSW
  • Interests
    Anything with an engine or electronics, I'm there.
  1. As far as I know to get the best bang you want something with a decent exhaust duration and not too much overlap, but that's purely from an efficiency point of view. You can fit it to anything, but the big limitation is ring end-gap and timing. To little gap and/or too much timing will blow an engine easy, as the ring ends butt together under heat expansion and blow the top off the piston and send it through the engine. I don't know how much the carburetor affects things, but I suspect its minimal in the standard operating range. As you said, the nitrous takes its own oxygen-rich atmosphere in with it as well as its own fuel (for a proper wet shot) so shouldn't need anything from the carb. Cheers for the advice, I probably should have emphasized the '9.75:1 or more' part of my post though, haha. I'm definitely looking to run some compression in her - I don't want less than 10.5:1 or its not really going to perform how I want it to at all, and I'll have to cam it down significantly to have it not be a complete dog under 4,000rpm. Biggest limiting factor for me is finding pistons with decent specs. The calculator I use is called 'Virtual Dyno', its a phone app based around a modified version of Dyno2000. Specs I'm working with as follows: 3.685" bore / 3.91" stroke (if I don't need an oversize, depends on what the 'reco' motor is) 0.00 deck height (yep I realise stock is about 0.030" down the hole) 6.8cc head gasket volume with 0.040" gasket 20cc piston dish 47cc head volume That gives 10.26:1 with little more than a decked block and head with standard .040 gasket. If I can get a hold of 12cc pistons that same combo will be almost spot on 11:1 with a 50cc head. Alternatively, if I get lucky with my C2 heads and can grab a .030" gasket then I'm looking at 10.75:1 with a 20cc dished piston. It all depends on what the engine pulls down like - that'll happen in the next few days. - boingk
  2. Thanks gents, good advice. I'll look at an extended breather as I don't mind a good set of corners... not that there are many out here. While I'm waiting for the shifter stuff to turn up I got a nice, big package dropped on the veranda: 15x7 sunnies! Beauty. Nothing flash but they're cheap and will hold a tyre so I'm happy. Meanwhile I'm still weighing up what camshaft to go with... a mild solid or a hot hydraulic... definitely leaning toward a mild solid, though, something 235@50 with 550ish lift is about where I want to be. That would be in between the two smallest Camtech offerings so should be alright with about 9.75:1 compression or more. Hopefully that's not too much of an issue. - boingk
  3. Alrighty, progress today was having a look at the shifter in the single-rail. It's got a pretty non-existant shift feel, you'll know what I mean if you've shifted any neglected manual box. Warning signs going in were multiple strands of wire holding something together, plus tek-screws in the shifter pot housing. WTF? (if you cant see a picture directly above this text let me know) There we go; worn and neglected. Going by this I'll probably drop the box and strip it so see what overall condition its in, but if its anything like this it'll be average at best. Either way I've ordered a proper metal-surround shift bush and a new saddle for the rail as it *did* shift and engage all gears without any harshness or gear whine so it may just need a good strip and refurb. If anyone has any good advice on rebuilding these boxes let me know - materials, tips & tricks, pitfalls for new players, all would be much appreciated. Cheers - boingk
  4. The engine in her is apparently 'recoed' but I really have no idea what they mean by that. It could be a simple bearings & rings job, or may just be a timing chain and head gasket. Hell, it could be some fresh paint and filters, who knows. Either way she's very stock at the moment, but not for long. I started a thread in Crossflow Tech (click here) for advice on the build before I got the ute and decided it'll be pretty conventional, with 4-barrel, camshaft, decent exhaust and ignition plus the nitrous. I've had a request to keep tabs on costs and am happy to share, but keep in mind I do ALL work myself and have since I was 16. No formal training, just learning how to do each new job as it crops up. As far as I see it if you have a space to work, some hand tools and a phone with the 'net you can get anything done in this day and age. Cost listing as we speak: $1000 - ute with reco 250 / 4spd / HD clutch / lotsa rims $250 - donor XF $250 - stud-mount roller rockers $240 - set of sunraysias in 15x7 $100 - new tonneau cover $100 - basic service (coolant/filters/oil/plugs) $50 - new tail lights $600 - Aussiespeed 4bbl manifold $600 - NX Mainline nitrous kit including plate, AN4 line, etc $70 - shifter kit for the single-rail ------------ $3260 total so far It sounds like a big chunk out of 5k but thats most of what needs doing so far. Here's a few pics of the current engine plus the one from the donor XF:
  5. Hey gents, thanks for having me aboard. I love inline sixes and doing things on a budget... so the natural candidate is a crossflow powered XF ute. I picked her up locally for the total sum of $1000, fresh out of rego and sporting a few goodies such as a 'recoed' 250 alloyhead crossflow, single-rail 4spd with HD clutch and a full set of snowflake alloys. She's not in the best nick but runs, drives, and gets around without too many issues. Hell, old mate even threw in a dash-mount CB. Goodo! The plan here is to turn her into something I can run to work and back in without dramas, but also take to the track and run mid-12 second passes. I'm looking to use nitrous oxide as well, so this makes things a bit easier as far as strip times and street driveability go. If I crack a 12.5 I'll be stoked, anything better than this is a bonus. The experienced might think this is a no-brainer, but doing it on a budget will be the real challenge - I want to get the lot done for $5k ready to roll. So, 12's for 5? Bring it on! Here's the candidate:
  6. Thanks mate, confirms what I was thinking all along. I'll be running 3.50's in the rear with M/T ET Streets so should go okay there with everything else similar. I've read up big time on the cylinder head so should be good for a home port job now I know where the gains and danger spots are. More than happy to mate. One of the reasons I like keeping score is so I know what I need to sell the car for if/when that time comes, as well as what to resell a part for. Hmmm, did that intake cost me $50, or was it $250? Mightn't make an earth-shattering difference at the time but it all ads up. Seen mates do that, never understood it. Best money for me is always spent on ignition, intake and valvetrain. Exhaust comes a very close fourth. The air pump analogy is always a good one here. I'm hoping with a goal in mind the plan isn't too hard to nut out right the first time, but we'll see where I am inn a few months I suppose. Anywho, onto the build thread - I picked up a ute the other day. I'll make a dedicated build thread in short order.
  7. Look at the engine you are building and decide on the most cost effective way. There will be positives and negatives each way. For a given engine, example a 250 crossflow, a zero-decked flat top might give you too much compression with even a stock head, but a stock piston will give you only average compression with a stock head. If you want something in the middle a mild dish and machined head may be the way to go. There is some evidence floating around that a mild dish helps centre the force of the combustion and helps with initial squish and also pre-ignition. This passes the common sense test in that you will get some good charge distribution from the narrow sides forcing charge into the centre as the piston rises, and have a friendlier shaped combustion chamber floor with regard to pre-ignition. The shape of a chamber is more important than the volume, but there is a limit where a good shape and unshrouded valves of appropriate sizes can all co-exist. Generally this is a nice semi-hemispherical chamber with rounded, smoothed contours focussing on the valves edges. Short answer? See what is reasonably available for your engine and go from there.
  8. Thanks mate, duly noted. I'm starting to think a bit more that way but again I'm also not looking to run 10's or even 11's. Mid 12's would be plenty for me - enough to have a play at the track with some V8 gear and not look shamefully slow. Low 12's would be a bonus but I expect the engine won't be the only thing holding me back by that point. Good reading, cheers for the link mate. Nice ride! Nah not much. Cheap ute, an engine to build while I drive it and sort the gremlins, and a whole lot of elbow grease by yours truely. I'm not a mechanic by trade but have tackled most jobs so far by myself. This is why I'm starting a year out - the magic triangle: Lotsa time / Lotsa money / Lotsa effort. Pick two and you may not need the other! Cost list so far: $1000 - ute with reco 250 / 4spd / HD clutch / lotsa rims $250 - donor XF - motor, radiator, spare trans / housing / flywheel etc $240 - set of sunraysias in 15x7 $100 - new tonneau cover $100 - basic service (coolant/filters/oil/plugs) $50 - new tail lights $50 - new hardline for fuel system $100 - new fuel pump $600 - Aussiespeed manifold $600 - NX Mainline nitrous kit including plate, AN4 line, etc ------------ $3090 total so far Budget about a grand for the camshaft, rockers and pushrods, another 200 in machining the head, 700 in M/T ET Street's, 150 for new diff gears and all I've got left is the carby... which I probably already have. Call it about another 1200 and I'm set. So whats that 4290 bucks? Not nothing but certainly far from big bucks, only thing missing is a decent ignition. If you have a place to work, some basic tools and a phone with the 'net you can get any job done. - boingk
  9. Fair call. With adjustable rockers solid lifters become just a quick purchase away... Looking at two choices here from Camtech: CT142-609: i231/e235@.050" / i496/e500 lift / 2200~6200rpm / min 9.5:1 compression CT142-608: i241/e243@.050" / i522/e522 lift / 2500~6500rpm / min 10:1 compression The top choice looks like it'd be great for everyday use which is 95% of what I'll be doing, and the bottom one would be a hoot for a more dedicated machine. They are the smallest in the range but that's fine by me as, like I said, this will mainly be a street-driven, full-rego type car with only occasional strip time. Anyone have experiences with those? And yeah looks like ACL is down and out. Bugger.
  10. Thanks mate, solid lead there. 1.75" would be nice, the things I have at the moment look very spindly (press bent 1.5"?) and were bought for a mild hop-up with another vehicle. ACL do pistons according to their website: http://www.aclperformance.com.au/EU/6MKRY9412.htm With the dished set at .020 over, a 50cc chamber, .030" deck height and .040" head gasket at 3.7" bore diameter it all comes to about a 10.8:1 compression ratio by my calculations. That should be plenty for what I want to achieve and still use pump fuel. I also stumbled on some bolt-in style roller rockers which look interesting, they use a 5/16 stud that goes into the head which then enlarges to a 7/16 stud for the rockers themselves. Anyone have any experience with this type of setup? I know its not a proper full 7/16 stud but then again I'm not running a top-spec full-tilt camshaft either. - boingk
  11. Thanks mate, much appreciated. I'll look more toward that direction then, if the valve gear won't hold I won't try and make it. I'm more used to Chrysler V8's and their great shaft-mount system and I keep forgetting how different stud type rockers are in terms of reliability at speed and load. Weight-wise, the ute is going to be pretty standard. I'll probably try and pull a few tricks (single sheet bonnet and tailgate, light tonneau cover for aero) but otherwise will be fairly limited as I want it to be usable as an everyday ride. Decent exhaust isn't an issue, big single 3" dumped out the back. Headers will be a struggle as off-the-shelf items don't have the primary size I'm after, at least not the one's I've seen so far. Ignition I'm leaning towards a 6AL style box or an ICE ignition module. I've had decent experiences with them so will see what I can get within my budget. Narrowing down the options for the final Ute body at the moment, I'll start a thread once I've got it. - boingk
  12. Thanks mate, well into it but not doing anything near that hectic. Pretty sure he's campaigned an XF ute in Drag Challenge for a few years now, too. I'm running an XF ute as well, nothing fancy at all and pretty rough at the moment. Cutting and patching panels type of rough. Looking to eventually run mid 12's, nothing fancy. Want to stay hydraulic flat-tappet for the camshaft to make thing easy, but what I'm looking at will be into the territory of a baby mechanical flat-tappet by most grinders catalogues. - boingk
  13. Hey all, just the usual here, asking for advice on a build. I'm not new to engines (Hemi 245's, 318's, Ecotecs, numerous bike engines) but am new to crossflows and need some advice. I'm looking to build something to take to the 1/4 and also run on the street. It'll likely have direct-port nitrous at the strip but other than that nothing too crazy. Combination so far is as follows: C2 head decked, ported and lapped 8cc pistons (balanced) to boost compression into the high 9's / low 10's Rods de-flashed and balanced Crank linished and balanced 120lb (closed) valve springs standard rockers/locks/retainers hardened CroMoly .110" thickness pushrods Camshaft somewhere in the neighbourhood of 230'@.050" and .520-.550" lift Ignition is up in the air, as is intake. I've got a ported Torker 2bbl and modded Holley 500cfm 2bbl I could use, but also am eyeing off the Aussiespeed 4bbl units to match with a Holley 600 / Street Avenger 670. This will come down to availability as the Barra craze is in full swing. The topend is also new to me, but essentially the same as my Clevos - the rockers would be lovely to swap out to at least a roller tipped type but will standard cope with the specs above and no more than 6500rpm? Any advice much appreciated, cheers.
  14. Hi mate, I've seen this drawing as well. The sectional drawing reveals a very thin lower intake wall on the short-side radius and runner, so be careful if porting anywhere there. I would limit to a quick swiffer to remove casting defects. What you would be better doing is concentrating your efforts to the outside / top of the runner as it will help with the gently curved profile of the runner in encouraging flow numbers. From a peak of about 180-ish cfm you should end up with 200 to 210cfm is you do a decent job. - boingk