Javascript Disabled Detected

You currently have javascript disabled. Several functions may not work. Please re-enable javascript to access full functionality.

Engine Dyno 202

Started by _Bluejinx202_ , Mar 19 2013 06:41 PM

Please log in to reply

24 replies to this topic

#1 _Bluejinx202_

Guests

Posted 19 March 2013 - 06:41 PM

So it looks like I'm off to the Dyno again, last time wasn't very successful because (I think) the tuner at the time wasn't willing to put the ign timing into it that it needed and I pretty much wasted alot of time and money. I'm going to re ring the old engine and put the new comp cam in bump up the compression to 12:1 or so and see what happens. I'm using a different dyno this time so hopefully the ignition will be tuned properly rather than guessed what is ok like last time.

Any suggestions as to what to try and what to spend the time on. I'd like to work out the cam timing but changing the position of a crank gear is a big job when I'm paying by the hour. I'm thinking of investing in getting a vernier gear made up for the day?

Back to top

#2 _Bomber Watson_

Guests

Posted 19 March 2013 - 06:55 PM

Would that be any faster? You still need to pull the belt, the balancer, the timing cover (to do this properly the sump as well) and then adjust the vernier gear, NOt much extra effort and probably an extra minute each time to pull the gear off, warm it up and slide it back on....

Cheers.

Back to top

#3 _Bluejinx202_

Guests

Posted 19 March 2013 - 07:07 PM

I'd be cutting a timing case up to make access easier. I wouldn't be taking the balancer off with what I have in mind.

Back to top

#4 _Bomber Watson_

Guests

Posted 19 March 2013 - 08:01 PM

OK, so adjustable cam gear with a hole in the timing case, stop the oil coming out via some form of magic....

I like your thinking, fill in the blanks and it could be cool....

Cheers.

Back to top

#5 _oldjohnno_

Guests

Posted 19 March 2013 - 08:18 PM

FWIW I wouldn't be worrying about changing the cam timing, I'd just install it at 4 - 5deg advanced. Once it's tuned I'd try a couple of runs with looser/tighter lash just to see what the engine wants cam-wise. If it really responds well to changes in lash I'd be more inclined to get another cam than to advance or retard it any more than a degree or two.

When you build it pay particular attention to piston-to-head clearance (35 to 40thou) and to making sure you have an appropriate CR. While it's on the dyno it'd be interesting to check the individual EGTs (if you're using the carb rather than the EFI that is).

Back to top

#6 _Bluejinx202_

Guests

Posted 20 March 2013 - 02:57 PM

When you build it pay particular attention to piston-to-head clearance (35 to 40thou) and to making sure you have an appropriate CR. While it's on the dyno it'd be interesting to check the individual EGTs (if you're using the carb rather than the EFI that is).

Is it a problem if I don't have that 35-40 thou? It's a bit of a long story, but when I first built this engine years ago, the head I had at the time had chambers to suit a 186 and I had to lose some comp. I had to use a standard acl with a dish and then decked the block 40 thou to get the piston in the right spot. Next time around I used a freshly ported head and acl race flat tops that were hanging out of the bores 40 thou so I had them put in a piston vice and milled to get them down. I thought it had enough clearance, but if you remember a post on "noisy rocker/lifter/valve" it turned out to be piston to head contact at high revs. The head has been off a couple of times and I've die ground the edges of the piston where the contact was. I now have slightly arrowed shaped pistons and if I want to change it I think I need to change blocks and start again. In the end I think the pistons are up about 20 thou with the edges ground to deck height.

If I go to extractors instead of the x2 headers I can probe all the pipes in the dyno but at the moment all the middle cyls exhaust in the same pipe. The x2 headers work for me because my engine runs backwards and it's easy to turn the pipes back around to go towards the timing case. If I make a set of extractors it would face the wrong way on dyno so probably couldn't use them anyway..

Back to top

#7 _oldjohnno_

Guests

Posted 20 March 2013 - 06:57 PM

Is it a problem if I don't have that 35-40 thou?

I don't see any problems with having less clearance, so long as there is no contact. And so long as the ground-down areas of the piston aren't any lower than the block deck you should be fine.

Re the exhaust I was just curious to see what the distribution is like with the Holley. I have a sneaking suspicion it isn't all that flash and that the EGT's might provide some clues on how to improve things. I guess if you wanted to you could throw on an old set of conventional extractors just for the EGT measurement, and it'd be interesting to see how they compare to the X2 manifolds.

Back to top

#8 _Agent 34_

Guests

Posted 20 March 2013 - 07:06 PM

Old johho,

can you explain the " lash " that you talk about in the cam timing area please.

looser/tighter lash just to see what the engine wants cam-wise

thanks in advance grant

Edited by Agent 34, 20 March 2013 - 07:06 PM.

Back to top

#9 _Bomber Watson_

Guests

Posted 20 March 2013 - 07:37 PM

Should wait for Johnno, but i'll take a punt, so he can correct me so i konw what he's on about to.

I assume he means the valve lash, and heres my assumption as to why this lets you see whats happening.

Loosening the valve lash would make the valve start moving later in relation to the cam lobes operation, thus making the engine think the cam is retarded.

Tightening it would make the valve start moving sooner in relation to the cam lobes operation, thus making the engine think the cam is advanced.

Considering the opening and closing ramps are fairly shallow on most cams, a couple of thou valve lash would be equal to a couple of degrees moving the cam, or thereabouts.....

Now i sit back and wait to be told how much of a retard i am

Cheers.

Back to top

#10 _oldjohnno_

Guests

Posted 20 March 2013 - 07:47 PM

You got it Bomber, I'd say you're no more retarded than I am. Though that's not really much of a compliment...

Here's how Harvey Crane describes running "lash loops":

1. Set the lash COLD at the specs furnished with the cam. Test and record ALL the numbers.

2. Tighten the INTAKE only lash .004 thousands (0.1 MM) and see if the recorded numbers are better (OVERALL) or worse. Use a GRAPH of these numbers for a better view of overall data.

3. If the numbers are BETTER continue TIGHTENING the lash in .004 increments and record all the numbers.

4. If the numbers are WORSE LOOSEN the lash in .004 increments and
record all the numbers.

5. Find the BEST OVERALL GRAPH and use this lash to run this same procedure on the EXHAUST LASH.

6. After finding the best lash for the exhaust, rerun the INTAKE "LASH LOOP" for any possible improvement.

This LASH LOOP method will also tell you if the engine needs a different PROFILE on the INTAKE or EXHAUST lobes. A MUCH TIGHTER intake lash indicates you might request an intake profile with MORE DURATION AT FIFTY THOUSANDS CAM LIFT. Request at least FOUR or FIVE degrees !

Of course, if the LASH LOOP says more lash was better, you need LESS DURATION in these same size steps.

Back to top

#11 Heath

I like cars.

Administrators
18,314 posts

Name:Heath
Location:Eastern Suburbs, Melbourne
Car:Heavily Modified UC Sunbird Hatchback
Joined: 07-November 05

View Garage

Posted 23 March 2013 - 03:28 PM

Loosening the valve lash would make the valve start moving later in relation to the cam lobes operation, thus making the engine think the cam is retarded.

Tightening it would make the valve start moving sooner in relation to the cam lobes operation, thus making the engine think the cam is advanced.

Considering the opening and closing ramps are fairly shallow on most cams, a couple of thou valve lash would be equal to a couple of degrees moving the cam, or thereabouts.....

Yeah... but you're not moving the centre of the lobe in relation to the crank though, you're just lengthening or shortening the duration.

They are definitely different adjustments.

Back to top

#12 _Bomber Watson_

Guests

Posted 23 March 2013 - 03:44 PM

Its a guide, i didnt mention the (to me atleast) obvious change in duration because that wasnt the subject matter....

Back to top

#13 _oldjohnno_

Guests

Posted 23 March 2013 - 05:55 PM

Yeah... but you're not moving the centre of the lobe in relation to the crank though, you're just lengthening or shortening the duration.

They are definitely different adjustments.

Agreed. Given enough available dyno time you'd probably test different centrelines and lash loops. The reason I suggested testing different lash settings is simply because it's something that can be done quickly and easily. Plus it allows small changes to be done to the intake and exhaust sides independantly in an attempt to get a rough idea of what the engine wants on either or both sides.

Back to top

#14 xu1kid

Forum Fan

Members
364 posts

Name:anthony
Location:Albury
Car:lj gtr xu1
Joined: 30-December 08

Posted 28 March 2013 - 09:00 PM

to realy tune it u should run your full efi setup and like old johnno says run 6 egt sensors then u can see what cylinders are running lean or rich via temps also timing shouldnt be hard for a good tuner , depending on what ecu u have u might not be able to tune in full sequential (eg) the ability to richen or lean specific injectors , if not and u are running batch fire ul have to find a happy medium, good luck

what figures did the engine make previously

Back to top

#15 _Ned Loh_

Guests

Posted 24 April 2013 - 12:58 PM

So it looks like I'm off to the Dyno again, last time wasn't very successful because (I think) the tuner at the time wasn't willing to put the ign timing into it that it needed and I pretty much wasted alot of time and money. I'm going to re ring the old engine and put the new comp cam in bump up the compression to 12:1 or so and see what happens. I'm using a different dyno this time so hopefully the ignition will be tuned properly rather than guessed what is ok like last time.

Any suggestions as to what to try and what to spend the time on. I'd like to work out the cam timing but changing the position of a crank gear is a big job when I'm paying by the hour. I'm thinking of investing in getting a vernier gear made up for the day?

Have been under a rock for last few months so only just reading this now.

Have you had run on the dyno yet?

Given this thread http://www.gmh-toran...e-4#entry732950 what dynamic compression will you have with this combo?

Back to top

#16 _Bluejinx202_

Guests

Posted 07 May 2013 - 07:17 PM

First of all, I would like to give something back to forum members by showing how a ba falcon crank scraper fits amazingly well onto a 202. All main cap bolts line up with the holes in scraper and the clearance on counterweights and big end bolts are freakishly close.

On other matters... The engine is coming along. A set of stainless 6 into 1 extractors have been sourced, just need the collector and the last 8"s or so replaced as that part is not stainless and has rusted away.

A new flex plate/ flywheel is getting manafactured complete with dry sump gilmer drive gear for 2 stage scavenge on a half wet half dry sump (baffle in middle with oil pulled out of low shallow end of sump and side covers put back into deep half with ba falcon windage tray over the top) compression ratio selected, (thanks OJ)

Now the next thing is, fuel. I will run this engine on 98 during social outings and holidays, but for race days am considering methanol for this engine. I understand that I need new needle and seats, and metering blocks for the 570. I'm told my edelbrock SBC fuel pump should be ok aswell (it's the higher flow model) any tip or advice on the fuel. And also the collector for the 6 into 1's I have to remake. Should it just be a funnel with the 6 pipes with a 3" outlet like it was before or some sort of megaphone merge setup?

Edited by Bluejinx202, 07 May 2013 - 07:23 PM.

Back to top

#17 warrenm

Forum Fixture

Members
2,107 posts

Location:Central West NSW
Car:1972 LJ Torana
Joined: 08-November 05

View Garage

Posted 08 May 2013 - 07:19 AM

That windage tray looks good.

Whilst I use methanol as a fuel, look at E85 as it gives some the properties that methanol has without being as harsh on the fuel system & you could leave it in all the time for social events as well as racing.

The collector needs to be longer than the one you have pictured, what length are the pipes from the flange to the start of the collector?

Back to top

#18 _Bluejinx202_

Guests

Posted 08 May 2013 - 01:30 PM

what length are the pipes from the flange to the start of the collector?

They are about 1100 long or 43.5"

Back to top

#19 warrenm

Forum Fixture

Members
2,107 posts

Location:Central West NSW
Car:1972 LJ Torana
Joined: 08-November 05

View Garage

Posted 09 May 2013 - 07:16 AM

If your using the cam in you other thread, I'd be aiming at 34-37"(865-940mm) for the primary pipes. The merge is a bit short, probably should be around 6"(150mm) long taper down to 2.75" or 2.5" with a total of 19" then to a muffler or open pipe.

Back to top

#20 _oldjohnno_

Guests

Posted 09 May 2013 - 07:37 AM

If it was me I'd pick one fuel and stick to it. And unless I really needed the bit of extra power from methanol I'd stick to petrol. Methanol has only a small power advantage over a well tuned petrol setup and its other advantages like cooling are going to be a non-issue in a boat.

I tend to think that once you've built the engine and dropped it into place you're only about halfway there, if that. The next step is to tune it and optimise it, and this usually involves trial and error testing of things like exhausts, advance curves, fuel curves, valve lash, rocker ratios etc etc. All this takes time (it never really ends), but it's worth it and I'm sure many races have been won by inferior combos that have been more thoroughly set up and tuned than the competition. Different fuels will want different things, and the last thing I'd want would be the distraction of working with two different combos.

I agree with Warren's comments on the exhaust. It'll be hard to get a nice transition with a 6>1 collector though I think Burns sell them. Alternatively you could split it into two 3>1s. And thanks for the windage tray tip; it's a beauty.

Back to top

#21 _Bluejinx202_

Guests

Posted 17 May 2013 - 10:43 AM

If your using the cam in you other thread, I'd be aiming at 34-37"(865-940mm) for the primary pipes. The merge is a bit short, probably should be around 6"(150mm) long taper down to 2.75" or 2.5" with a total of 19" then to a muffler or open pipe.

I've been playing aroun with the pipes, they are I bit odd in length so just fiddling to get to equal lengths. I think I an get the 34-37" ok and I understand the 6" long collector, should be able to make that, what's the total 19" though? I've got a 3" pipe with no muffler so I could make the collector taper to 2-3/4 and out again to 3".

Back to top

#22 warrenm

Forum Fixture

Members
2,107 posts

Location:Central West NSW
Car:1972 LJ Torana
Joined: 08-November 05

View Garage

Posted 18 May 2013 - 06:34 AM

The 19" refers to the total collector length, from the end of the primary pipes to the open end of the

collector or start of the muffler.

The pic may make it clearer.

Headers 1(600 x 436).jpg 32.5K 4 downloads

Back to top

#23 N/A-PWR

CABIN ENGINE CONTROLS GALORE

Members
9,595 posts

Name:Dave I
Location:Wooroloo, 65km's East of Perth
Car:'1969' LC RAT TORANA
Joined: 08-December 12

Posted 11 July 2015 - 04:57 PM

First of all, I would like to give something back to forum members by showing how a ba falcon crank scraper fits amazingly well onto a 202. All main cap bolts line up with the holes in scraper and the clearance on counterweights and big end bolts are freakishly close.

Hi James,

Just checking, is the way you have the Windage tray,

the correct way around for the oil scraper scoop/fins ( what ever they are called)?

As I can imagine the tray going on 180 degrees to the way you have.

Like Button for you. :spoton: