It is currently Tue Dec 18, 2018 2:31 am

All times are UTC + 10 hours




Post new topic Reply to topic  [ 861 posts ]  Go to page Previous  1 ... 34, 35, 36, 37, 38, 39, 40 ... 44  Next
Author Message
 Post subject: Re: Our little cultus racer
PostPosted: Tue Oct 09, 2018 6:56 pm 
Offline
User avatar

Joined: Mon Oct 12, 2015 11:30 am
Posts: 286
Location: Napier
Ooooh yes that would be nice. Weight saving is my thing for my car, where I can. Stainless has a nice ring to it too. I would much prefer the original 4-2-1 perhaps with larger secondaries? Then again, I should just by the turbo kit that is on here.

Sad thing is, the parts fund is empty. It might be able to recover soon but I am putting the van back on the road so all my $$$ is going there.

_________________
A Kiwi learning to fly in a Mk1.


Top
 Profile  
 
 Post subject: Re: Our little cultus racer
PostPosted: Wed Oct 10, 2018 10:50 am 
Offline
User avatar

Joined: Tue Feb 23, 2016 5:38 am
Posts: 354
Location: Amberley
Like all these things, there never as easy as first seems. Autobend can't digitise extractors without taking them apart. The tool they use would require the flange cut off and the primaries separated to record the shapes. The alternative is to take the existing extractor as an example and create a design in a CAD tool, like SolidEdge, that can then be used for the CNC bender. The only drawback of this approach will be the cost. They're guess is at least 3-4 hours or around $250 but it could be more.

They're estimates to supply the pipe and do the bending are as follows:
Primaries - 4 @ $107
Flange - 1 @ $208
Collectors - 1 @ $164

so around $800 plus gst in 304 stainless. The per item production cost saving for multiple sets is minimal but obviously the design cost is a one-off and becomes less significant with more sets. I guess it does also mean that while we can use the Janspeed extractor to measure fit we don't have to follow it in terms of primary length and diameter.
Attachment:
IMG_4973.JPG
IMG_4973.JPG [ 1.31 MiB | Viewed 14 times ]


Top
 Profile  
 
 Post subject: Re: Our little cultus racer
PostPosted: Wed Oct 10, 2018 4:16 pm 
Offline

Joined: Mon Dec 19, 2016 10:40 am
Posts: 665
Location: NZ
ouchies Sam :? ...but i guess thats the price for building cars that are not Honduhs. lol.

Looks like i might have to stick with the cast manifold for a while yet. or make my own at some stage. 8-[
even getting ones from aussie that are still being made for the barina might only be $500. But thank you very much for the effort and trouble to check it all out.

on another note i have some details re the cams...I am told to set the intake at 106 degrees before TDC using the intake centreline method which is the ideal position with 110 degrees of overlap. at least I can check the correct position accounting for the planing of the head and block.


Top
 Profile  
 
 Post subject: Re: Our little cultus racer
PostPosted: Wed Oct 10, 2018 7:02 pm 
Offline
User avatar

Joined: Tue Feb 23, 2016 5:38 am
Posts: 354
Location: Amberley
Yeah, obviously building them in stainless is always going to be considerably more expensive than mild steel. From memory the tube is something like 5x the price of mild steel. I don't mind the price of the materials and bending, as it's really the only way to make a professional job, but I certainly don't want to cut my existing extractor to digitise the pipes and I'm not so sure about the design cost. Really need to learn to use SolidEdge or something similar.


Top
 Profile  
 
 Post subject: Re: Our little cultus racer
PostPosted: Thu Oct 11, 2018 12:52 am 
Offline

Joined: Mon Dec 19, 2016 10:40 am
Posts: 665
Location: NZ
Definately don't want to cut ya pipes! #-o
Fairly hard to guess it and use bends and straights as well. It's always an option I suppose.
I wonder if my cams suggest a four into one might be better......given the strong midrange to upper mike says they work in.

Have to make a piston stop tool today. I'll use an old head with valve springs off so I can check for clearance with the edges of the valves....dunno how close they will get.

I have to find TDC anyway as it's not marked on my trigger wheel.
Decreeing the cams will be difficult. I have to use a solid lifter and I don't have one...also not keen to remove the cam :twisted: always trickier than it first seems.


Top
 Profile  
 
 Post subject: Re: Our little cultus racer
PostPosted: Fri Oct 12, 2018 8:08 pm 
Offline

Joined: Mon Dec 19, 2016 10:40 am
Posts: 665
Location: NZ
I made a part today that fits into the centre of the pulley. I printed a crank degree wheel and pasted it onto a stiff bit of cardboard. Then attached it to the plastic bit I made. Bent up a bit of tig filler rod. Made a piston stop. Found TDC. Marked the trigger wheel. Then looked at the cam pulley settings. As expected....both retarded by a little. I guess the surfacing of the head and block may have something to do with it. Now I need to degree the cams.

One problem is the hydraulic lifters. I don't want to remove the cams....and I don't have any solid lifters. The inlet centreline method requires the position of maximum lift....hydraulic lifters will bleed down screwing up the measurements....bugger it.


Attachments:
IMG_5651.JPG
IMG_5651.JPG [ 681.17 KiB | Viewed 16 times ]
IMG_5650.JPG
IMG_5650.JPG [ 680.44 KiB | Viewed 16 times ]
Top
 Profile  
 
 Post subject: Re: Our little cultus racer
PostPosted: Mon Oct 15, 2018 1:04 am 
Offline

Joined: Mon Dec 19, 2016 10:40 am
Posts: 665
Location: NZ
Hey Sam what size is your header tubing mate? And where is your four into one collector? Also....it seems if I go too big in pipe size I’ll lose performance. If I were to make a set of mild steel headers to test do you think with our dog box and reasonably aggressive cams of 222 duration and 365 thou lift which are more a high RPM cam that it may be advantageous to try a four into one....??? It’s just easier to make!

I realise a few key things. 1. The pipe diameter is critical, 2. The length of all header tubes must be equal (volume I guess) and the overall length of the header until the four into one collector impacts upon performance.

Ok...I have checked my manifold....it’s the only one I have....if it cracks and leaks the worst case scenario is the mixture riches out? (No onboard lambda to change mixture)?

If I fit a header later I’ll have to retune?

So far the four into two into one on the stock manifold worked bloody well. Thanks to Blake’s input. The reason to try a header is twofold. 1. The stock is HEAVY. 2. They crack and no spares. So....making a four into two into one is harder than a four into one. The first one helps torque....the second high rpm power. We know we are low on torque. That begs for the first type. However it’s a high rpm performing camshaft that pulls well from midrange to top. Is it worth trying the four into one?? On a stock box everyone would say no....but we have a dogbox with a max speed of 195kmph at 8300 rpm and 30kmph between changes after 1st gear. So if we learn to drive like those awesome drives (Harris etc) and keep it in the power then it may work.

Comments both positive and negative welcome....especially those that have been there are done that! 8-[
Thanks guys.


Top
 Profile  
 
 Post subject: Re: Our little cultus racer
PostPosted: Mon Oct 15, 2018 7:12 am 
Offline
User avatar

Joined: Fri Sep 03, 2010 10:41 am
Posts: 1369
Location: Bunya QLD 4055
Once made the 4/1 is difficult to modify for tuned length but the 4/2/1 requires the modification of only two pipes. I think my solution will be to order a set of SS 1600 pipes from SuzukiRD in Florida which will be around AU$535 delivered and then mod them. They have none and will not be making anymore of the G13b pipes so the 1600s should be cost a effective solution. When is your next Florida hiatus?

_________________
If "X" is an Unknown quantity, and a Spurt is a drip under pressure, then an "EXPERT" is an "Unknown Drip Under Pressure".
Why dont they just call it "Womenapause" instead.


Last edited by pictureshowman on Mon Oct 15, 2018 11:57 am, edited 3 times in total.

Top
 Profile  
 
 Post subject: Re: Our little cultus racer
PostPosted: Mon Oct 15, 2018 8:08 am 
Offline

Joined: Mon Dec 19, 2016 10:40 am
Posts: 665
Location: NZ
Cheers Picture.
They use 1/34" pipe for the 1.3 and 1.6 16 valve engines. Is that too big? I wonder what the difference in the centreline of the exhaust ports is between the 1600 and our g13b engines is? Anyone know?


Top
 Profile  
 
 Post subject: Re: Our little cultus racer
PostPosted: Mon Oct 15, 2018 8:20 am 
Offline
User avatar

Joined: Tue Feb 23, 2016 5:38 am
Posts: 354
Location: Amberley
The primaries are 38.1mm od. The collector is directly under the sump, it starts just behind the gearbox brace and ends at about the rear edge of the sump. I think 4 into 1 is the way to go. For the type of use you should be able to stay on cam. If anything a 4-2-1 would work better for what I do but I'm not about to change.

They're hard to make accurately. Yes, you'll be able to make a neat and tidy manifold that doesn't leak but it's unlikely to be equal length if you're building it from u-bends. This sort of problem is what computers are made for. Get something designed in a CAD tool where the primaries are calculated to be equal effective length and then get the tubes made in a CNC bender. There should be no reason for it not to be correct first time and if you do decide that smaller/larger primaries or shorter/longer might work better then you have the design that you can tweak. It will cost to get the design done but it will be cheaper than having several goes at building them from u-bends.


Top
 Profile  
 
 Post subject: Re: Our little cultus racer
PostPosted: Mon Oct 15, 2018 8:30 am 
Offline

Joined: Mon Dec 19, 2016 10:40 am
Posts: 665
Location: NZ
Ok...looks like the 1.5" tube should be the go. Yes I agree it will be hard to make accurately. I wish we could just buy them ready to go!
Getting them designed....wouldn't know where to start....seems a shame as others have done it all before. Maybe just stick with the cast boat anchor and buy a Chinese spare I guess. :?


Top
 Profile  
 
 Post subject: Re: Our little cultus racer
PostPosted: Mon Oct 15, 2018 8:48 am 
Offline
User avatar

Joined: Tue Feb 23, 2016 5:38 am
Posts: 354
Location: Amberley
Why not flick Janspeed an email and see if they will still make one to order. I'm guessing they'll have digital designs for all their previous products so making a one off of an old design might not be a big deal.


Top
 Profile  
 
 Post subject: Re: Our little cultus racer
PostPosted: Mon Oct 15, 2018 9:28 am 
Offline

Joined: Mon Dec 19, 2016 10:40 am
Posts: 665
Location: NZ
https://www.deaperformance.com.au/p/Ext ... R/HU283STM

Have a look guys. DEA will get me a ship price. They have 4 into 2 into 1 as well as these???


Top
 Profile  
 
 Post subject: Re: Our little cultus racer
PostPosted: Mon Oct 15, 2018 12:34 pm 
Offline
User avatar

Joined: Tue Feb 23, 2016 5:38 am
Posts: 354
Location: Amberley
Can't say I've ever seen Hurricane headers on this side of the ditch. Might be all right, looks like the correct size primaries. Bit hard to tell regarding the length or collector. Shipping wouldn't be cheap so the total would probably trigger GST so I'm guessing the all up cost would be around 600nzd.


Top
 Profile  
 
 Post subject: Re: Our little cultus racer
PostPosted: Mon Oct 15, 2018 12:54 pm 
Offline

Joined: Mon Dec 19, 2016 10:40 am
Posts: 665
Location: NZ
Ok I've decided to at least try to build a header. I'm going with the simple looks of the suzukird type setup. Not being 4 into 2 into 1 I guess there is no issue with what tube is mated anywhere.

The hurricane headers have no1 and 4 on the top and 2,3 on the bottom. I'll have 1 and 2 on the top and 3,4 on the bottom. 1 and 2 have a greater angle whereas 3 and 4 will be longer out of the head and into the collector. I'll make sure all header tubes hold the same amount of fluid before welding.

I have bought a collector (well 2 as they come in pairs) for 1.5" tube. 4 into 1. Exit is 2.5".
My exhaust pipe is 2.25" so I have a bit of tweaking there.

I have a cultus pipe that has been cut up to use the flange off it (tks Blake)

I'm going mild steel and I'll high temp paint and cure it. Cheapest way to do it and try it. Around $220 I reckon.

I have two bungs and two caps for OXY sensors from amazon.

I'll post progress and of course results.

I'll start the collector just below the sump to just behind it.


Top
 Profile  
 
 Post subject: Re: Our little cultus racer
PostPosted: Mon Oct 15, 2018 7:11 pm 
Offline
User avatar

Joined: Mon Oct 12, 2015 11:30 am
Posts: 286
Location: Napier
Why not follow their design and use 1+ 4 on the top, that way you will have 2 fewer angles to work out with 2+3. They can just run straight.

_________________
A Kiwi learning to fly in a Mk1.


Top
 Profile  
 
 Post subject: Re: Our little cultus racer
PostPosted: Tue Oct 16, 2018 5:01 am 
Offline

Joined: Mon Dec 19, 2016 10:40 am
Posts: 665
Location: NZ
Which one are you talking about Michael?

If I want to do mandrel bends....and it's just one bend on each end like the suzukird ones (wish they still made them be a darn site easier) I need to account for the angle the engine sits. I can go 90 degrees out of the head but it would need to be less....I'm estimating 83 degrees or something like that. If I get bends it's a lot more shagging about. And won't be smooth.

Picture....I have no idea how much modding the 1600 suzukird headers would need....maybe easier just to start fresh?

Of course I'll mock up a spare motor.....I have a block, head and sump I'll pop on the engine stand soon as I get home. Then I can set my merge collector under the sump and tack weld some bits to hold it in place exactly where I want it. Then I'll use tig wire to run the centres of the tube....two equal length pieces of wire bent differently to fit. Then I'll measure angles etc....and talk to autobend.

I have hedged my bets by buying two collectors. One from NZ which is a simple mild steel collector relatively short for standard bent 1.5" mild steel tubes to fit on my mild steel flange....and a very sweet looking 304 stainless steel merge collector. If I go with that I'll need a stainless flange and tubes. Then there will only be two lengths of mild steel tube in the exhaust system....the rest would be stainless. Lachie can bend the 1.5" mild steel but it's not mandrel bent. Probably not much of an issue as it's not over 90 degrees. If I go that way I can sell off the merge collector. Have you seen the price of them in NZ!

Having said all that. It's about $200 difference between the stainless setup and a high temp coated mild steel setup. I can do the stainless setup for $400-450
I'd honestly leave it all alone if the manifold was ok....but with hairline cracks and no spare 8-[ 8-[ 8-[ 8-[


Top
 Profile  
 
 Post subject: Re: Our little cultus racer
PostPosted: Tue Oct 16, 2018 5:19 am 
Offline
User avatar

Joined: Tue Feb 23, 2016 5:38 am
Posts: 354
Location: Amberley
The order into the collector isn't accidental. It will have been worked out to be diagonally opposite for firing order. The actual position in the collector probably won't matter but the order should have an affect.

With your primaries, being equal volume will help but you need to consider the affect of the amount of curve. Gas will flow faster down a straight pipe than around a curve so a slightly shorter pipe with more bends will have the same tuned length as a slightly longer straighter pipe. You also need to consider where the outlet should be. It would normally be directly under a line between pots 3 & 4 so primaries 1 & 2 can't be the same length( will need to be longer ). You'd expect 3 & 4 to be the shortest with a little extra bend to achieve the same tuned length. Whether they're in the top or the bottom of the collector will also be a factor. Hope you were paying attention in maths.

This would be ideal long haul reading ( after you've pressed the auto pilot button ) https://www.amazon.com/Four-Stroke-Performance-Tuning-Graham-Bell/dp/0857331256.


Top
 Profile  
 
 Post subject: Re: Our little cultus racer
PostPosted: Tue Oct 16, 2018 6:14 am 
Offline

Joined: Mon Dec 19, 2016 10:40 am
Posts: 665
Location: NZ
Interesting. Both the hurricane headers and the suzukird headers approach the same 4 into 1 concept differently Sam. Suzukird has 1 and 2 on the top of the collector. Hurricane has 1 and 4. Now I get that on a 4-2-1 system 1 and 4 compliment each other as do two and three to create a vacumn in their partners pipe to help scavenging during valve overlap.

But I fail to see how all four heading into one collector can make a difference. Perhaps opposite tubes firing or adjacent tubes firing....on a merge collector there is a diamond shape in the middle to aid in gas flow. I get the curve diff required to ensure equal lengths. Do you think the suzukird header is an ok design? Cheers g


Attachments:
IMG_5656.PNG
IMG_5656.PNG [ 2.68 MiB | Viewed 13 times ]
Top
 Profile  
 
 Post subject: Re: Our little cultus racer
PostPosted: Tue Oct 16, 2018 6:39 am 
Offline
User avatar

Joined: Tue Feb 23, 2016 5:38 am
Posts: 354
Location: Amberley
I guess we're talking very small gains. The primaries into the collectors are either arranged diagonally opposite or in firing order sequence around the collector. Have a look at few other examples and you'll see the pattern. Almost all 4's have the same firing order so looking at extractors from other engines will give you an idea. I'd say look at something known to work and copy.

It's a bit hard to tell looking at the picture of the Suzuki RD extractors. Looks like they've arranged it to suit the lengths. The collector is closer than the port spacing so ideally primary 2 would want to be slightly tighter than 1 but really hard to tell if it is. If you believe what you read very few are equal tuned length.

Are there any other fwd's with the same port spacing? That is, cut off the flange and weld on the G13B flange.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 861 posts ]  Go to page Previous  1 ... 34, 35, 36, 37, 38, 39, 40 ... 44  Next

All times are UTC + 10 hours


Who is online

Users browsing this forum: No registered users and 9 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © phpBB Group