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Spark plug heat range?


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#1 Donyboom

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Posted 13 March 2018 - 01:04 PM

Hey guys,
Just wondering what your thoughts are on my spark plug colour. I have a 202 blue running aftermarket efi and cdi ignition and I am trying to reduce ping. I am running 11:1 compression mild cam, and I believe I may be getting high combustion temps. Running bp 98.

I was running bp6efs-13 as per pics. I swapped to bpr7efs-15 and it pinged worse, coloration has not changed. AF ratios look fine. I’m thinking of going to bp8efs and a colder thermostat.

The reason I’m going to a cooler thermostat is if I take temps from the head sensor it’s up around 100c. If I take it at thermostat it’s 84 so I’m thinking the combustion is way too hot.

Currently anything above 20degrees adv at 3000rpm is ping city. I have to wait until 4500 and by then it doesn’t need it...

3bd4a6177e38eaaf646c88021171069d.jpg

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This bottom one here you can see the earth strap starting to melt in the Center.

Cheers.


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#2 lawn bowls

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Posted 13 March 2018 - 10:18 PM

maybe 20 degreese is a bit to much timing try going down 1 degree at a time until detonation goes away.



#3 rodomo

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Posted 13 March 2018 - 11:39 PM

Have you checked that the balancer hasn't slipped? Also do you have the right timing cover to match your balancer?

#4 Donyboom

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Posted 14 March 2018 - 10:06 AM

Thanks for the replies!

I'm using a new red Romac balancer and red timing cover so all good.

I've read that timing should be all in by 3500rpm and that they like upwards of 28degrees so it's got me fd. Anyone out there know what a standard curve is in 500 rpm increments?




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#5 koalasprint

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Posted 14 March 2018 - 12:56 PM

A couple of things to try.

 

#1 Verify the timing mark yourself. Use a dial indicator or any other instrument/method to find TDC on #1 cylinder. Check the position of the timing mark. My 308 was 4 degrees out! Incorrect timing will cause temperature issues.

 

#2 Try some octane booster. You might find that the compression is too high for that camshaft. 11:1 compression for a camshaft duration over 240 degrees at 50 thou. If your combination is the problem you'd need to either drop compression(thicker head gasket), run octane booster, change camshafts, pull timing or a combination. Timing and octane booster being the easiest but maybe not the best.



#6 Donyboom

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Posted 14 March 2018 - 02:15 PM

I’ll double check but is a new Romac balancer. One other think I hadn’t considered however is that my timing light may be out. I suppose if it was off by 2 degrees I could be at 14degrees initial. But that still wouldn’t account for the other 6 degrees.

On another note if I use 98 from some independent stations it tends to ping.


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#7 koalasprint

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Posted 14 March 2018 - 03:17 PM

The timing mark relies on:-

                                             Crankshaft accuracy, machining of the key way in relation to the #1 journal.

                                             Harmonic balancer accuracy, machining of the matching key way in relation to the timing mark/s.

                                             Timing cover. Index markings in relation to both above.

 

Your timing light is probably ok unless it has the dial back feature that's up the creek.

 

To find exact true TDC wind over the engine until piston is at TDC. Reset dial gauge to zero. Turn over engine until piston is 50 thou below TDC. Mark the balancer position. Keep turning over engine until piston is back on the way up and back to 50 thou down. Mark balancer position once more. True TDC is in the middle of these two marks. Hard to explain, I hope it makes sense. Easy to do with the head off. Still possible with the head on though.



#8 lawn bowls

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Posted 14 March 2018 - 03:54 PM

white is lean,



#9 ozyozyozy

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Posted 14 March 2018 - 08:28 PM

Agree with others, def check for true TDC and having a good quality dial back style timing light are very helpful.

Due to cam and compression, even combustion chamber design your timing requirements could be completely different to other engines.
May need your dizzy advance to be recurved bring in advance slower.
Having a dizzy that you can adjust how fast and how much advance can be very helpful.
Some performance engines dont like alot of timing.
Usually on high strung engines if you can hear the ping by ear then its way too much and way too late.
Good tuners run a knock sensor to noise canceling headset, for very close monitoring of timing on a dyno.

#10 Donyboom

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Posted 15 March 2018 - 08:19 AM

white is lean,


According to Bosch colour chart whit is also too hot. If I wind up the fuel map by 10% the afs go through the roof however the plugs remain porcelain white like this!?

Regarding the dizzy. My dizzy is locked and I have full control of the curve through the ecu. I just can’t understand why I can only get 20 degrees out of this engine. My conclusion is heading towards to high compression. I’m going to check the timing mark shortly.

Thanks everyone!


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#11 Donyboom

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Posted 15 March 2018 - 08:49 AM

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Ummmmm yeah high compression me thinks lol.


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#12 koalasprint

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Posted 15 March 2018 - 11:43 AM

Try some octane booster. If that works you can keep doing that, look to change camshafts(bigger) or drop compression.

 

Is compression on all cylinders close to 190?



#13 lawn bowls

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Posted 15 March 2018 - 12:59 PM

if your going to try octane booster use nulon pro strenght its the best about $25 a bottle.cheap insurance.



#14 Donyboom

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Posted 15 March 2018 - 09:38 PM

Try some octane booster. If that works you can keep doing that, look to change camshafts(bigger) or drop compression.

Is compression on all cylinders close to 190?

Yep pretty much around 190.

I don't think octane boost is going to cool the combustion down enough. I'll just turn down the timing and think about a cam with big overlap. Clearly what it needs I think. I was considering a thick head gasket. Can anyone tell me what thickness gasket might lose a CR point?

Other option could be e85 but they sell it here for $1.40!

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Edited by Donyboom, 15 March 2018 - 09:40 PM.


#15 lawn bowls

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Posted 15 March 2018 - 09:57 PM

mix half 98 and half e85 and try it.it looks like detonation marks on the side of the strap on the spark plug in the second picture.



#16 S pack

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Posted 15 March 2018 - 10:05 PM

I reckon just try the Nulon Octane booster that lawn bowls recommended. Mixing half & half 98 with e85 may still be too much ethanol for your fuel system to handle unless you've set it up for e85.



#17 lawn bowls

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Posted 15 March 2018 - 10:30 PM

i think the octane booster will be a better option s pack,try using a 7 heat range donnyboom,



#18 koalasprint

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Posted 16 March 2018 - 10:37 AM

Yep pretty much around 190.

I don't think octane boost is going to cool the combustion down enough. I'll just turn down the timing and think about a cam with big overlap. Clearly what it needs I think. I was considering a thick head gasket. Can anyone tell me what thickness gasket might lose a CR point?

Other option could be e85 but they sell it here for $1.40!

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Good that all cylinders are the same.

 

I suggest the octane booster to reduce/stop pinging, then you can increase timing and that will reduce temperatures.

 

To work out gasket thickness i have to make assumptions. So here we go.

Bore size: 3.655 inch(30” over), Stroke: 3.25 inch, Combustion chamber volume: 48 cc, Piston to deck height:  .003 inch, Gasket thickness: .040 inch, Gasket bore diameter: 3.7 inch, Dome/Dish or Valve relief: 0 cc, Piston ring height: .250 inch, Piston crown diameter: 3.655 inch. This gives static comp ratio of 11.02. If we go to a .059(1.5mm) gasket the ratio changes to 10.44.

Precision sell a Durapro gasket. http://www.precision...&Stock=GSAG390D

 

To drop the full one point you'd need a gasket 0.075" (1.9mm) thick.

 

Try the octane booster first to make sure we are on the right track.



#19 Donyboom

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Posted 16 March 2018 - 10:14 PM

Good that all cylinders are the same.

I suggest the octane booster to reduce/stop pinging, then you can increase timing and that will reduce temperatures.

To work out gasket thickness i have to make assumptions. So here we go.
Bore size: 3.655 inch(30” over), Stroke: 3.25 inch, Combustion chamber volume: 48 cc, Piston to deck height: .003 inch, Gasket thickness: .040 inch, Gasket bore diameter: 3.7 inch, Dome/Dish or Valve relief: 0 cc, Piston ring height: .250 inch, Piston crown diameter: 3.655 inch. This gives static comp ratio of 11.02. If we go to a .059(1.5mm) gasket the ratio changes to 10.44.
Precision sell a Durapro gasket. http://www.precision...&Stock=GSAG390D

To drop the full one point you'd need a gasket 0.075" (1.9mm) thick.

Try the octane booster first to make sure we are on the right track.



Ho lee fark I thought Steven Hawkins died the other day! Thanks for the fairly accurate ballpark you gave me there I’ll give the octane boost a try next week and go from there. Much appreciated!


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#20 Donyboom

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Posted 16 March 2018 - 10:18 PM

mix half 98 and half e85 and try it.it looks like detonation marks on the side of the strap on the spark plug in the second picture.


I agree on detonation! Didn’t know about mixing half e85 and 98. I’ll try octane boost next week. Cheers.


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#21 LC-GTR-1969

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Posted 18 March 2018 - 07:28 AM

Is this a newish engine or something you bought from elsewhere and as is? 

 

You might want to have a look through the plug holes to check for excessive coking on the pistons- could cause pinking and contribute to the high heat. You AFR may be on the lean side too. You should be able to run 7s in that engine. Any colder and its a bandaid... Also, remember that AFR is an average of all cylinders- so its not a true indicator of what is actually happening in each pot. Also, what AFR are you running at idle, cruise and then under WOT full load?

 

As others said, confirm timing. Confirm possible air leaks etc... My engine made most power with 27 degrees timing in locked dizzy (200hp at the wheels)- but most would think to run, say 32 degrees and shes safe... not in my setup though. 



#22 Donyboom

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Posted 19 March 2018 - 01:12 PM

Is this a newish engine or something you bought from elsewhere and as is?

You might want to have a look through the plug holes to check for excessive coking on the pistons- could cause pinking and contribute to the high heat. You AFR may be on the lean side too. You should be able to run 7s in that engine. Any colder and its a bandaid... Also, remember that AFR is an average of all cylinders- so its not a true indicator of what is actually happening in each pot. Also, what AFR are you running at idle, cruise and then under WOT full load?

As others said, confirm timing. Confirm possible air leaks etc... My engine made most power with 27 degrees timing in locked dizzy (200hp at the wheels)- but most would think to run, say 32 degrees and shes safe... not in my setup though.


Idle is high 13s

Cruise is 13.5 : 14.5

Light accel in the 14s

Wot 11 : 12

Engine was purchased off eBay only done say 20k. I’ve done 5k.
I’m going to get a bore scope and check the cylinders.

It’s a great runner I just think there is something strange about lack of timing and head temps.

Cheers


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Edited by Donyboom, 19 March 2018 - 01:17 PM.


#23 I'm a Red Motor fiend

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Posted 19 March 2018 - 02:39 PM

Lack of timing = higher temps tho?
How do you know static comp is 11:1 and not say 11.5:1? Do you know your cam specs at all? If it is only a mild cam then of course it's going to ping with higher comp.
if it's a good runner with nice bits on it, I would pull the head and the cam. Verify your static comp properly and your cam specs and inspect the bores. Then put it back together to suit. It's not a huge amount of work really......

#24 LC-GTR-1969

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Posted 19 March 2018 - 03:03 PM

Idle is high 13s

Cruise is 13.5 : 14.5

Light accel in the 14s

Wot 11 : 12

Engine was purchased off eBay only done say 20k. I’ve done 5k.
I’m going to get a bore scope and check the cylinders.

It’s a great runner I just think there is something strange about lack of timing and head temps.

Cheers


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The AFR all look fine from here but as mentioned, they are only an average between cylinders so this needs to be kept in perspective. 

 

When you say lack of timing, what is your timing at total? You said 20 initial/ idle, which is fairly high with the level of cylinder pressure/ compression you have.. I run 27 locked but this is with a cam running about 115 degrees of overlap, where as a mild cam will not need anywhere near that level of timing. 

 

I would imagine a good setup with good dynamic comp with mildish cam, say 40/60 or thereabouts to want about 12-16 initial and about 30-32 total. 16- 20 advance in the curve should be close to ok. If your dizzy hasn't been recurved, or not done correctly, then you will find your total timing could be real high. This has happened to me when I had a dizzy recurved- it was suppose to have 10 degrees advance in it- but they actually, mistakenly, put 16 degrees in it- so when I set my timing at 20 degrees I was actually running 36ish total, which was WAY too much for my engine. 

 

If I were you I would check all the basics, confirm TDC, confirm advance actually in the dizzy.

 

BTW there is a reasonably good octane boost called OCTANIUM- its from VP fuels and can genuinely add quite a lot of octane to your fuel if needed. Might be worth a try.. from memory it was $27 per can when I bought it. Half a bottle will turn 40 litres of 98 into 102 octane. Just be mindful that its not safe for 02 sensors in high concentration (dont use a full can if you plan on running your 02 sensor).

 

Also, what induction you running? Do all 6 plugs look the same when pulled?


Edited by LC-GTR-1969, 19 March 2018 - 03:05 PM.


#25 Donyboom

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Posted 19 March 2018 - 05:44 PM

The AFR all look fine from here but as mentioned, they are only an average between cylinders so this needs to be kept in perspective. 

 

When you say lack of timing, what is your timing at total? You said 20 initial/ idle, which is fairly high with the level of cylinder pressure/ compression you have.. I run 27 locked but this is with a cam running about 115 degrees of overlap, where as a mild cam will not need anywhere near that level of timing. 

 

I would imagine a good setup with good dynamic comp with mildish cam, say 40/60 or thereabouts to want about 12-16 initial and about 30-32 total. 16- 20 advance in the curve should be close to ok. If your dizzy hasn't been recurved, or not done correctly, then you will find your total timing could be real high. This has happened to me when I had a dizzy recurved- it was suppose to have 10 degrees advance in it- but they actually, mistakenly, put 16 degrees in it- so when I set my timing at 20 degrees I was actually running 36ish total, which was WAY too much for my engine. 

 

If I were you I would check all the basics, confirm TDC, confirm advance actually in the dizzy.

 

BTW there is a reasonably good octane boost called OCTANIUM- its from VP fuels and can genuinely add quite a lot of octane to your fuel if needed. Might be worth a try.. from memory it was $27 per can when I bought it. Half a bottle will turn 40 litres of 98 into 102 octane. Just be mindful that its not safe for 02 sensors in high concentration (dont use a full can if you plan on running your 02 sensor).

 

Also, what induction you running? Do all 6 plugs look the same when pulled?

 

Its ecu controlled timing. I use 12 initial and cant go past 20 total degrees all in by 3500 or it will ping at 3500rpm. distributor mech advance is locked.

 

 

As for the specs no i dont have the exact info on the cam but i was told xu1 cam and 11:1 comp ratio. It doesnt have a very lump idle so i think its a mild grind tbh. 

 

Bit of a prick taking cams out when the engine is in the car on lc toranas. Almost easier taking the engine out. 

 

lack of timing would make high temps but the pinging stops me from going too far. chicken or the egg?

 

All plugs look identical. I am using vk efi manifold with vn commodore throttle body and ford ba falcon injectors.

 

if i set the timing below it doesnt ping

 

idle:12

1000: 13

1500:14

2000:15

2500:16

3000:18

3500:19

4000:20

4500:21

5000:23

5500:24

6000:24

 head temps around 100c

thermostat temps 84c : 86c

 

anymore timing after 3000 = ping






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