Show Posts
|
Pages: [1] 2 3
|
2
|
Technical Board / Modification Help / Re: 186 vs 202 differences
|
on: September 22, 2010, 05:59:24 PM
|
...202 pushrods are longer as well, I'm not sure where the extra length is made up, maybe the deck height of the block?
Colin.
The deck heights are all the same; it's the type of rocker gear that determines what length pushrods to use. Late rockers with the aluminium bridge use a different length to the old ball-pivot rockers. If you use studmount rockers on a head that didn't originally have them though you'll also need guideplates.
|
|
|
3
|
Technical Board / Modification Help / Re: 186 vs 202 differences
|
on: September 21, 2010, 07:08:02 PM
|
The cheapest option by far will be to scrounge around for a good 202 block. The 202 pistons are shorter than the 186 ones so won't work with the 186 crank, even though the bore size is the same. And the 186 cranks have a smaller main journal diameter so the 202 crank won't just drop into your 186 block without a lot of machining. Rods, cams etc. are interchangeable. If you can find a 202 that hasn't been excessively overbored (most you come across these days are already +0.060") you can just swap over all the good bits from your old motor. A blue or black would be nice because they came with Starfire rods (if your old motor doesn't already have them) but keep in mind that if you use a later block then technically you'd be required to use the corresponding emissions controls.
ps. Go Tux!
|
|
|
4
|
For Sale and Wanted / Parts Wanted / Re: holden bonnet letters
|
on: September 14, 2010, 06:55:09 PM
|
I have 1 H 3 O's 1 L 2 D's 1 E & 3 N's
You can have the lot for $20 plus postage
Regards Ken
Do you still have these Ken? If you do - and fcvwking doesn't want them - I'd like to buy them. John
|
|
|
5
|
Technical Board / General Technical / Re: Do FC Holdens fix themselves??
|
on: September 13, 2010, 06:44:49 PM
|
Speedo began not working, working, not working, then eventually died altogether. Sought some advice and bought a second hand speedo cable. Pulled mine out to find the two cables matched exactly, there was no break in my original cable. Put the second hand one in just in case. Speedo still didn’t work. Was given (thanks Darcy) a second hand speedo, also bought two for parts at the Auction Swap. Pulled mine out to fit the second hand one. Tested mine with a variable speed cordless drill and it worked perfectly. Put mine back in. Sought more advice and moved further down the line. Dismantled the speedo drive out of a spare gearbox to learn as I go. Pulled mine out of my gear box, tested it and it worked fine. Put it all back together and NOW MY SPEEDO WORKS FINE, with the second hand cable, original speedo in the dash and the same drive in the gear box. So do FC Holdens fix themselves?? or Does the exercise of just moving things around make them work??? Well they sort of fix themselves. The thing is there was never really a problem, it just craved some attention. It's obvious when you think about it: FC=Female Car, nice to look at but a bit leaky at times and sulky (or downright malicious) if you don't lavish enough time and money on them. The speedo was never really faulty, she was just feeling unloved and wanted you to spend some time on her. Now everythings fine. Until next time...
|
|
|
6
|
Technical Board / Restoration Help / Re: 138 Re Build
|
on: August 08, 2010, 08:31:55 AM
|
One thing I have been told a few times:
If you have an engine rebuilt, never let it sit around. Don't assemble your engine until you intend to use it. The weight of everything makes the bearings go out of round over a period of time. When you start it, disaster.
If you do rebuild an engine and it sits around for a while, every now and again, build up oil pressure with a drill or whatever and turn the engine a few times by hand.
I'm sure others will have other opinions, but I have been told this by several different people over the years.
Colin.
That's a myth. The crush on the ends of the shells ensures that they stay round, and lots of complete engines have been stored for many many years and started without problems. There are a few things you can do to help preserve a stored engine (besides the obvious ones like storing it somewhere very dry). There are special anti-corrosive storage oils that can be used, alternatively most of the multi-purpose agricultural oils have similar properties to help protect machinery that is parked up for a long time. I like to remove or at least loosen the rocker gear so all the valves are closed (and the cylinders sealed) and the springs relaxed though it's probably not really necessary. Keeps the wasps out though.. Tape up the intake and exhaust too. If you are going to turn it over periodically I'd stop at a different spot each time so you don't always have the same spring fully compressed but again it doesn't seem to matter. Before startup I like to remove the plugs and overfill it with oil. The very high oil level lets the crank splash oil onto the bores while it's cranking over. Once you have oil pressure and flow to the top end you can drain the excess, fit the plugs and rocker gear and fire it up without problem. I've done this with several engines that have been idle for many years without dramas.
|
|
|
7
|
Technical Board / General Technical / Re: Sliding vane supercharger
|
on: July 29, 2010, 09:40:06 PM
|
Thanks Keith, yes 100 ci is what I was thinking in regard to capacity. The point of inlet and exhaust port relate to the position in the charger barrel where the ports need to be machined apparently not exactly diametrically opposed this is due to noise levels and efficiency.
Rob
One of the features of vane type blowers is the fact that they have their own internal compression ratio and therefore the exhaust port opening point isn't really critical. So long as the port has sufficient area for good flow and it closes when the segment between vanes is at its minimum volume it will be ok. The intake port generally will have a longer duration - theortically it would open immediately after reaching minimum volume and close upon reaching maximum volume. In practice you'd want to delay the opening - the internal compression ratio mentioned earlier means that there will be some "trapped" pressure so in the interests of noise reduction the chamber is allowed to expand somewhat before the intake opens. If you use peripheral ports one of the challenges will be maintaining even wear of the vane tips. Most vane type blowers/motors use phenolic or carbon vanes; some like the old Shorrock used a complex system to maintain a small clearance between the vane tips and the housing. Vane blowers were always regarded as being a bit less efficient than a Roots blower; I'd expect a modern Roots design such as an Eaton to be quite a bit more efficient. Sounds like an interesting project though..
|
|
|
8
|
Technical Board / General Technical / Re: 12 port Alloy head
|
on: October 05, 2008, 01:36:48 PM
|
Ok for anyone interested these are the numbers for the 12 ports (at 0.4" lift and 28" suction): Standard 202 black - 115 to 120cfm Ported black w 1.74" intake - 165cfm I don't have any 9 port heads handy but would expect to see about 90 cfm for a stocker depending on valve size. By comparison - and I promise I won't use the "P" word this time - an EF Falc. flows about 205 and a 3 litre 2JZ Toyota does about 225cfm in bog stock form. FC427, do have any numbers for the JZED head? I imagine they would be pretty big... The general rule of thumb is cfm/4 x no. of cylinders = horsepower potential. This is naturally aspirated of course, and on pump petrol. It usually works out to be fairly close for a reasonably well developed engine.
|
|
|
9
|
Technical Board / General Technical / Re: 12 port Alloy head
|
on: September 29, 2008, 09:16:35 PM
|
oldjohnno I crew for JZED on his FED and he has the National Record with a Holden six he took the title of a Rotary so much for Holden six's not performing .....7.7 at 168MPH must be slow or Pathetic ? .....FC427....... I envy you FC427 being involved with that car.. I only wish I could build something equally slow and pathetic
|
|
|
10
|
Technical Board / General Technical / Re: 12 port Alloy head
|
on: September 28, 2008, 10:16:56 PM
|
I feel bad about the "pathetic" remark actually, I was probably being overly harsh. For any "normal" use they are fine and I have to admit my stock 149 performs sweetly and is perfectly adequate. I guess I just didn't want anyone kidding themselves and wasting money trying to build something that would beat 2JZs, RB30s, LS1s or whatever and being disappointed when it didn't happen..
|
|
|
11
|
Technical Board / General Technical / Re: 12 port Alloy head
|
on: September 28, 2008, 04:59:12 PM
|
I wasn't aware the 12 port alloys were going to be re-released so I don't know if it's the same product as was available previously or if it has been reworked. Alloy heads have the advantages of lighter weight, a quicker warmup and slightly less tendency to detonate, plus they have the big benefit of being easy to weld for the purposes of repairs or modification. I have spent a lot of time playing with Holden 6 build ups, and there isn't a lot of good reliable information available. I tested some stock 12 port heads and also spent some time (too much!) modifying and testing a couple of 12 port EFI heads. From memory (and I'll drag my notes out to verify this later) the stock 12 port head flowed somewhere around 130cfm, and with a lot of work I ended up with about 160cfm from the VK one. All these flow figures are at 28"h2o and 0.45" lift by the way. So you can see that the scope for improvement with the 12 ports is nowhere near as big as what it is with the old 9 port heads. Mind you, the stock 9 port head is truly abysmal, and a typical 9 port YT head would be somewhere around 140-150 cfm. To put all this in perspective, I tested a (used and slightly crusty) stock standard EF Falcon head and got a smidgen over 200cfm. Yella Terra used to claim up to 35% better flow from their 12 port heads, so that would put them somewhere around 170 - 180 cfm. I gave up on the 12 port heads (and the Holden 6) eventually, the gains were getting smaller and smaller and the walls thinner and thinner. If you really are serious about getting the most from a Holden 6 - and to be honest they really are pathetic compared to modern engines - try talking to the guys that race Group NC. They are getting over 300hp from NA 9 port motors and if you must run a Holden motor they can point you in the right direction. You might also want to read these notes : http://www.bur.st/~oljohnno/holden.html. If I can find my flow test notes on the 12 ports I'll post them up.
|
|
|
13
|
Technical Board / General Technical / Re: heavy clutch pedal
|
on: January 14, 2008, 07:05:49 AM
|
Ken, To reduce the pedal effort wouldn't you want to use a bigger slave cylinder, and/or a smaller master? My take on it is that if the clutch doesn't start to engage until the pedal is at least halfway up you can afford to trade some of the excess clutch travel for a reduced effort. And you can do this by changing the leverage ratio at the pedal or throwout fork, or by changing the cylinder(s). If however the clutch engages when the pedal is not far from the floor there is nothing you can do short of putting in a lighter pressure plate. Or taking steroids.
|
|
|
14
|
General / Events, Shows etc / Re: WSID Nostalgia pics/videos
|
on: January 02, 2008, 06:13:26 PM
|
Both sets of pics are brilliant, some amazing looking cars there. The Rootes Racing bucket caught my eye, is that a Humber six? Not something you see every day at the drags, thats for sure..
|
|
|
16
|
Technical Board / General Technical / Re: gm superchargers
|
on: December 29, 2007, 09:29:16 PM
|
I should have added that the little 6:71 blowers are plenty big enough for a street small-block, so assuming the "14:71" is an big blower based on the 71 series unit it would probably be grossly oversized..
|
|
|
17
|
Technical Board / General Technical / Re: gm superchargers
|
on: December 29, 2007, 08:29:49 PM
|
I've been working on these old 2 stroke GMs for many years. They have been known as Detroit Diesels for a long time now, though many of the old timers still call them GMs and the basic design goes back to the late 30s. The modern Detroits are completely different 4 stroke engines. Stinky is right; the first number refers to the number of cylinders and the second the capacity of each cylinder. Common capacities are 53, 71 and 92 cu in/cyl. There is a bigger one too (149 cu in I think) though I've never worked on those. Common configurations are straight 3, 4 and 6cyls, and vee 6, 8, 12 16 and 24s. Some of the bigger motors are made by bolting two or more blocks/cranks together and use two individual blowers, often with two heads per bank as well. The 53, 71 and 92 engines all use different size blowers, and the inline blowers are different to the vee engine ones. I've heard hot rodders refer to 14:71 blowers too even though no such engine exists and suspect it may be a term coined by the US race blower builders. If you measure the rotor diameter and length I could probably work out what it came from. They aren't that hard to rebuild if you're careful, I could probably email scans of the relevant manual pages if you need them..
|
|
|
20
|
Technical Board / General Technical / Re: Combustion Chamber Volume 149/161 Head
|
on: December 02, 2007, 11:57:35 AM
|
You're welcome. The figures actually came from an old post of Dr Terrys. At the risk of teaching you how to suck eggs, here is the formula - maybe someone else will find it useful. (One cubic inch equals about 16.39cc)
CR=(D + V + DC + G + CC) / (V +DC + G + CC)
CR = Compression Ratio
D = Displacement of one cylinder
V = Piston Volume (will be a negative value with a domed piston)
DC = Deck Clearance Volume
G = Gasket Volume
CC = Combustion Chamber Volume
|
|
|
|