Building a 10,000 rpm NA engine.

[oab_au]

Originally Posted by Dessertrunner

When I look at the curves the rate of acceration is constant as the bulk of the distance travels is a straight line in the image you posted.

Please Harvey bear in mind that I haven't got a clue about what I am talking about, its just the tooth fairy side of my brain telling me this.

Also would say that I don't agree that the cam profile is the best because the closing is just a basic mirror of opening. Lost time because the start of closing could be a lot steeper and the final stage a lot flatter.
I am going to sound like a smart ass here but the dynamics of a cam are a lot different to the way they are thinking. Everyone is treating it wrong,

The load on a cam and valve opening is harder because the cam is fighting the spring as well as enerita.
When the cam closes the spring works with you there for acceration should be faster. So why don't they do this well I can only suggest that as the valve closes they need to reduce the volicity of the valve right down before it hits the seat. For some reason that escapes me they seem to think a fast closing valve will have issues.

Sorry Harvey but like I said I don't have a clue about what I am talking about other then to relate what my strange brain sees and what it currently is seeing is wrong.

So Harvey you got to enjoy a good discussion.
Tony

I can see what you are saying, but the spring load is insignificant compared to the load of the valve train itself. The Desmo cams don't use springs, but still use that profile cam, its just that the valve is forced to follow the cam profile, that does not have to conform to the harmonic action of a valve spring.

Harvey.

[Dessertrunner]

Originally Posted by oab_au

I can see what you are saying, but the spring load is insignificant compared to the load of the valve train itself. The Desmo cams don't use springs, but still use that profile cam, its just that the valve is forced to follow the cam profile, that does not have to conform to the harmonic action of a valve spring.

Harvey.

Your point is correct, if there is no spring. On a SVX with a spring we can take advantage of that spring and every spring bounchs if you let it so we can use that bouch to help speed up the closing stroke if we want. Just by pulling it closed the moment it reachs fully open.

[Dessertrunner]

Kind of disagree about the spring load as I see it, it is significant on a SVX other wises the valve doesn't close.

[Dessertrunner]

Have pulled the intake manifold off and installed the new top pipe thermostate housing on to the motor and now putting it all back together. On my last trip to the desert I stuck a hole in the condensor for the AC so I have pulled it out short term and I will run some tests on airflow throught the radiator with and with out the unit in place. I personally feel the SVX unit blocks the airflow to the radiator to much.

The current thermstate that is in the top housing is a 61C (140F) the aim here is to find out if we can keep the engine temp down around 71 - 77C which is in line with what they do on the V8 super cars in Australia.

Seem to remember that the Nissan GTR that I was in a couple of years back had a engine temp of 65C.

Will post photos and performance details as it becomes avialable.

Tony

[Dessertrunner]

Okay,
New thermostat housing fitted and job completed see attached photo. The way the final install work out was far better then I expected.
Testing to start now.




Tony

[Dessertrunner]

Well fired it up and what do you know the engine boiled but the radiator was stone cold. Head guages showed 110C and the radiator 40C it occured exactly like Bazza suggested and that is with still having the two smaller bypass pipes connected. I know what the problem is so I will fix it in the morning and run the next trial.
Tony

[icingdeath88]

Originally Posted by Dessertrunner

Well fired it up and what do you know the engine boiled but the radiator was stone cold. Head guages showed 110C and the radiator 40C it occured exactly like Bazza suggested and that is with still having the two smaller bypass pipes connected. I know what the problem is so I will fix it in the morning and run the next trial.
Tony

I was actually just looking at the engine in my storage last night to get a better understanding of how the cooling system is setup, and I had an idea that I think will fix that. What I think you need to do is move one of the bypass outlets from the back of the coolant crossover pipe to the front, as close as possible to where your top t-stat is now. That way it will get heated as the water does, and open when it should. Might be better also to delete whichever one doesn't get moved.

(bonus points if you can make the t-stat close the bypass as it opens)

I am at work, but if I can get a chance I will draw up a diagram in mspaint.

[SVXRide]

Originally Posted by Dessertrunner

Okay,
New thermostat housing fitted and job completed see attached photo. The way the final install work out was far better then I expected.
Testing to start now.




Tony

Tony,

Very clean! You wouldn't even know it's there unless someone pointed it out to you. Think you could take a pic or two of the bottom rad hose and how it attaches to the modified thermostat cover and modified lower radiator outlet?
Thanks.

Bill

[Dessertrunner]

Originally Posted by icingdeath88

I was actually just looking at the engine in my storage last night to get a better understanding of how the cooling system is setup, and I had an idea that I think will fix that. What I think you need to do is move one of the bypass outlets from the back of the coolant crossover pipe to the front, as close as possible to where your top t-stat is now. That way it will get heated as the water does, and open when it should. Might be better also to delete whichever one doesn't get moved.

(bonus points if you can make the t-stat close the bypass as it opens)

I am at work, but if I can get a chance I will draw up a diagram in mspaint.

Don't bother drawing it I understand what you mean. Have spent months trying to get the bypass to shut down when the thermstate opens and haven't had any luck as there is not much room. Also in our case it would have to be the heater pipe as its on the same side other wies the oppositte head would cook from lack of flow.

The solution to my issue is that I just need to drill a hole in the side of the thermostat, about 3 mm and that will be enough to open the thermostate. I will get that done and come back to you in the next hour..
Will also get the photo Bill.

Tony

[TomsSVX]

Mmight want to look into a failsafe stat like the one i used in dans car

Tom

[TomsSVX]

http://www.wilsonmanifolds.com/produ...ermostats.html

Tom

[SVXRide]

Originally Posted by TomsSVX

http://www.wilsonmanifolds.com/produ...ermostats.html

Tom

Tom,

Thanks for the info. I didn't realize that Chevy thermostats were the same size as ours.

Bill

[Dessertrunner]

Problem solved drilled a 4 mm hole in the thermostate and the problem has gone away. Opens correctly and due to the low temp state 61C the engine sits around 65c to 75 C. The day is due to be hotter around 34c so I will report back tonight on how the new set up behaves.

Tom that is a good idea would still need to drill it as the coolant does not get to the stat get it to open in the start. I think its smart the way it locks open.
One benfit of this new approach is the fan are never on other then when the AC is on.

Bill photos attached.
Tony

[TomsSVX]

Originally Posted by SVXRide

Tom,

Thanks for the info. I didn't realize that Chevy thermostats were the same size as ours.

Bill

Originally Posted by Dessertrunner

Problem solved drilled a 4 mm hole in the thermostate and the problem has gone away. Opens correctly and due to the low temp state 61C the engine sits around 65c to 75 C. The day is due to be hotter around 34c so I will report back tonight on how the new set up behaves.

Tom that is a good idea would still need to drill it as the coolant does not get to the stat get it to open in the start. I think its smart the way it locks open.
One benfit of this new approach is the fan are never on other then when the AC is on.

Bill photos attached.
Tony

Bill... its not... i used ut in their stat housing... which is why i recomend them.

Tony.... it works just fine... you could say "trust me"

Tom

[SVXRide]

Originally Posted by TomsSVX

Bill... its not... i used ut in their stat housing... which is why i recomend them.

Tony.... it works just fine... you could say "trust me"

Tom

Tom,
Thanks for the clarification!!
B