CHT

 Thanks for that Bruce. At least l know I'm not alone, was wondering if l had a faulty sender or gauge for a moment...

So the new gauges are in and working a treat. Only problem... they don't look right. Dakota have been really good and sent me some chrome bezels they also offer. Just getting round to fitting them after a few tweeks.

Tweeks all done... 

Dakota gauges with a face lift. Old school meets digital. 

WOW! That looks awesome, Rich! Nice job! 

Great improvement. Please describe how you did the facelift.

Richard,

Wow!  That is one terrific looking dash.  I like your steering wheel too.

 I love the gauges. . . and the more the merrier. Wish I had your mechanical skills and patience.

Who made your car?

 

 

terrific!!!

So, those are digital gauges with fake analog faces?  I've never seen that before.....I like it.

I still think that you must have had your heart in your mouth while cutting those two holes in the dash......   

Gordon Nichols posted:

I still think that you must have had your heart in your mouth while cutting those two holes in the dash......   

Richard is my new hero. That took some serious 'nads.

Yup.

Thanks for the feedback guys...

Michael McKelvey posted:

Great improvement. Please describe how you did the facelift.

Michael once you remove the bezel and the 3mm lense, you end up with this.

 

 

 

Gordon Nichols posted:

I still think that you must have had your heart in your mouth while cutting those two holes in the dash......   

Gordon, you must of heard the saying "measure twice cut once" if it didn't work then  what the hell, I'd of had to practise the glass fibre skills ;-)

That does look good.

Just so I've got it right, the analog part of the gauge is fake?

Not that I'm against it, our cars are fakes, I just wanted to be sure.

nice work!  those look great

Great idea.  Old look, new display.

Carlos G posted:

That does look good.

Just so I've got it right, the analog part of the gauge is fake?

Not that I'm against it, our cars are fakes, I just wanted to be sure.

100% fake anolog. Purely for when it's parked up at a show etc it'll look kinda correct. Rather than a black screen.

 

Hello guys, is anybody that monitors all 4 cylinders can share the rough temperature difference that should be normal between cylinders 1,2 & 4 versus 3 ?

 

I just finished installing my sensors and while at idle (its winter up here) I can see a big difference between 1 & 4 (about 100F).  Can't wait to have a drive and properly test my setup.

 

Thanks

jc

to alb, is that an old e production scca race car? and do you know the history of it? bill

 

They're just pics I've stolen from this great, big, interweb thing, Bucky. It's a road race car and I'm guessing they were trying to ensure a good supply of ambient air to pressurize the engine compartment enough so that not only could the carburetors and fan function as intended, the airflow through the engine compartment carried away most of the radiated heat coming off the engine so it wasn't all recycled and sucked up into the carbs and fan. I'd also be willing to bet that with the engine's radical state of tune (sky-high compression and 7500 or 8,000 rpm redline) they noticeably extended it's life between rebuilds by reducing operating temps. 356/912 engines are very expensive to build, so you can see the benefits! I remember Mr. Berg once saying that the difference in life between engines that normally ran at the upper and lower ends of normal operating temp parameters was in the neighborhood of 10-20,000 miles (or more). 

I've mentioned the aquarium tubing air pressure test before and Aircooled Bruce's oil temp observations were invaluable-

 https://www.speedsterowners.co...3#456308404198448633

https://www.speedsterowners.co...8#456449141718495878

Another way to check what's happening in the engine compartment is with a remote thermometer; with the probe on the middle of the fan shroud (near the throttle cable tube/coil area) you can get a reasonable idea of carb and fan intake temp. Someone on the Samba (who's info I trust) determined that getting more air into the engine compartment (of his 11 second street Beetle) to the point where underhood temps were only a few degrees above ambient made a significant difference in operating temps and how the car ran. He pulled the front breastplate (goes on top of the bellhousing) off and other than having to watch that he didn't run anything over (rags and plastic bags) that would get sucked into and block the fan, found it to greatly benefit.

Someone on here (sorry, can't for the life of me remember who you are at the moment) found that even at lower city speeds (driving around the beach area?) that a piece of pool noodle holding the engine lid ajar made a noticeable difference in oil temps- another indication of not enough airflow into the engine compartment. 

Ok- I'm done now. Yoda out (for now, but back you know I will be!)

Krusty posted:

Hello guys, is anybody that monitors all 4 cylinders can share the rough temperature difference that should be normal between cylinders 1,2 & 4 versus 3 ?

As far as I know, I’m the only one here that monitors all four cylinders besides Richard. I have analog gauges, so my readings are not as precise as his. If you are monitoring all four, that makes three of us. 

 Anyhow, to answer your questions –  here are my observations. The largest temperature gradation on my engine between cylinders is during warm-up. If your engine isn’t reaching full operating temperature, you are likely to experience the same thing.

By the time I’m fully warmed up, all four cylinders are within a few degrees of each other- certainly no more than 25°F of delta.

I’m also one of the few guys running a type-1 Raby DTM. I’m not 100% convinced that the $600 chunk of fiberglass I’m using is really that much better than the 36 hp copy everybody else is running, but I am sure the delta between my cylinders is a lot better than yours. 

Generally, when I get notice a lot of differential between the cylinder temperatures, I have something wrong in my carburetors. I know when an idle jet is starting to plug long before it’s a complete misfire by watching the gauges. This alone is worth the price of admission when I am out on the road.

I was around when Jake Raby was posting during the development of the DTM. His opinion (which makes a lot of sense to me) is that if you are going to have a delta between cylinders, you’d like to have it be as small as possible on the same head. In other words, temperature gradation side to side is nowhere near as important as front to back. If 3 and 4 run hotter than 1 and 2, it’s not really that big of a deal. But if 1 runs quite a bit hotter than 2, etc. – that’s something that will give you problems.  

What I’m doing is probably overkill, but I’ve been told “knowledge is power.” I don’t know if that’s true or not, but I do know I don’t regret having the information except when it’s time to change the spark plugs.

@Stan Galat I really like the idea of monitoring all four and plan to add 3 more in the future. Did you notch both heads for the 4 sensor rings? I'm totally blanking and can't remember notching #3 but I must of as the motor was out at the time. Sad when the mind starts to go...

Bill

I’m using sparkplug rings, which is why changing plugs is zero fun. 

i was wondering, it looked like my old scca  race car from the 70s and 80s bill
 Bill and Jean Demeter

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They're just pics I've stolen from this great, big, interweb thing, Bucky. It's a road race car and I'm guessing they were trying to ensure a good supply of ambient air to pressurize the engine compartment enough so that not only could the carburetors and fan function as intended, the airflow through the engine compartment carried away most of the radiated heat coming off the engine so it wasn't all recycled and sucked up into the carbs and fan. I'd also be willing to bet that with the engine's radical state of tune (sky-high compression and 7500 or 8,000 rpm redline) they noticeably extended it's life between rebuilds by reducing operating temps. 356/912 engines are very expensive to build, so you can see the benefits! I remember Mr. Berg once saying that the difference in life between engines that normally ran at the upper and lower ends of normal operating temp parameters was in the neighborhood of 10-20,000 miles (or more). I've mentioned the aquarium tubing air pressure test before and Aircooled Bruce's oil temp observations were invaluable- https://www.speedsterowners.co...9141718495878Another way to check what's happening in the engine compartment is with a remote thermometer; with the probe on the middle of the fan shroud (near the throttle cable tube/coil area) you can get a reasonable idea of carb and fan intake temp. Someone on the Samba (who's info I trust) determined that getting more air into the engine compartment (of his 11 second street Beetle) to the point where underhood temps were only a few degrees above ambient made a significant difference in operating temps and how the car ran. He pulled the front breastplate (goes on top of the bellhousing) off and other than having to watch that he didn't run anything over (rags and plastic bags) that would get sucked into and block the fan, found it to greatly benefit.Someone on here (sorry, can't for the life of me remember who you are at the moment) found that even at lower city speeds (driving around the beach area?) that a piece of pool noodle holding the engine lid ajar made a noticeable difference in oil temps- another indication of not enough airflow into the engine compartment. Ok- I'm done now. Yoda out (for now, but back you know I will be!)   View This Reply
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Stan Galat posted:

Bill

I’m using sparkplug rings, which is why changing plugs is zero fun. 

Yes, they say to notch the head for the rings (wire portion) to sit into. That way the ring won't turn when installing and removing the plugs.

@Stan Galat

After I notch the head, what should I do to hold the ring in the notch?

Michael, I'm not notching my head for spark plug rings. I bought these small K-type thermocouples that will get a self-tapping screw very NEAR the spark plug in the head fins.

I got them from Aerovee conversions(the people that make Sonex VW powered airplanes. They were $70 for all 4. I'll be installing them soon, I need to remove my shroud to change the voltage regulator anyway.

I promise to post pics when I install them, and I'll be monitoring ALL 4 cylinders.

http://www.sonexaircraft.com/e...&category_id=330

And yes, Richard, that took balls to cut your finished dash. I had to drill some holes for small switches, not a big deal. I bow to you!

Danny....I'm just guessing at this but I would think cooling fin temps are going to be much different than actual cyl head temps,  such as at the action center, the spark plugs. Did that company , Sonex,  give you any info on what the actual cyl. head temp is compared to the cooling fin temps at the recommended location of their sensors ? Also do they use a VW fan shroud to cool the engine in an airplane. The ones I have seen didn't. They relied on prop. wash and forward air flow. This may have a very significant/ different effect on cyl. head cooling compared to an engine in a car.  I don't know anything about this but my logic buzzer goes off on this one. Surely Sonex has done some testing on this and should be able to provide you with some useful info......Just trying to help.......Bruce

Bruce,

The difference between under the plug and slightly offset(did you look at the picture in the link?) was a few degrees to zero. My only source on this is Sonex. 

And yes, the ductwork they use is ram air/propwash from the front and the rear cylinders do get warmer than the front. However, my goal is differential between cylinders as I think that is more important than ultimate temp, adding in the convenience of not futzing with the plug sealing and changing procedure.

The thermocouple is installed in the top of the cylinder head less than an inch from the plug. I'm willing to bet this is fine for our purposes. If I really wanted to be that anal about it I could install EGT gauges........

Now if I was going to put the sensor farther away, say where the factory warmup sensor went, I'd agree with you Bruce.

I'd say we all wait until I get it installed and see results. As you know, there isn't a lot of solid metal in the heads. I even bought a bottom tap to do this thinking I'd be threading the holes. But the thermocouples come with self-tapping hex head screws and call for a number drill bit to properly clearance the hole.

@DannyP, did you buy the first of 4 listed?

I wonder if this would be compatible with my Dakota Digital gauge.

Thanks for the reply Danny. Yes...Please let us know what temps you get. Some of us here have the data from all 4 at the plugs. I also use a Dakota Digital gauge....bruce

I, too, am watching with great interest.

Michael, I bought 4 K-type for Aerovee(which is a VW engine). If the Dakota digital uses K-type thermocouples, then yes. They are only 4 feet long though so not enough for you.

Thanks, Bruce. I run a modified 911 shroud with vanes(part came off an SC I believe) on the back of the Porsche early(2.4) alternator. So I'm really interested to see the temps as well. I ran a sensor on #4 before, which is supposed run the hottest.

@DannyP, maybe I could mount my current sensor there with a big washer. Someone on thesamba suggested cutting the ring off the under-plug sensor and embedding it in a hole drilled in the head, perhaps in the same location.

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That's what I planned to do since I will be pulling my engine. Then that Danny guy planted ideas in my head.

He is a pretty good gardener...

Michael McKelvey posted:

That's what I planned to do since I will be pulling my engine. Then that Danny guy planted ideas in my head.

Sorry about that Michael.....

I thought I may be able to put the existing ring under a screw but in the photo above it doesn't look like there is enough room. I may try cutting the ring off and sticking what's left in a hole.