2110cc horsepower?

[catbox]

[Jimmy111]

Combustion chamber coatings are not a good Idea for most gasoline engines.
Again Ill say that the Autoignition temperature of gasoline is 496F. If you did not have the heat loss during compression you would have detonation and preignition problems at a 4-1 compression ratio.
These coatings claim that they keep the heat in the cylinder where it will provide more energy. But you need the heat loss to operate the motor properly. Because of the heat losses to the cylinder head you can have much higher compression ratios and so higher efficiency and power generation. Look closely at that video that I posted. It shows clearly that the cooler cylinder head does not ignite the F/A mixture. But the warmer piston does.
However if you had a diesel or a direct injection gasoline engine, these coatings would be great and allow for more efficiency and power generation.

And again Ill say that you just plain cant use 10-1 CR on a ACVW engine. I know that people do do it and claim that their engines run fine. But this is only because they are doing something else wrong like a pig rich F/A mixture or a high back pressure exhaust system causing too much reversion or some other similar mistake.

[mightymouse]

[EPETREA]

uh.. could the fact that type 4's are more aluminum than magneseum explain the fact that they are able to handle and like a higher temp?? Type 4s are not the same as type 1's obviously!!! apples and oranges.

Why is so much time being spent on the CR when there are plenty of other miscues in his engine combo. NOBODY is going to change their opinion on it so move on.

[Jimmy111]

[mightymouse]

[mightymouse]

[EPETREA]

well golly gee wiz beave!! I guess I did. Only thing I remember about his opinion on type 1's was the lack of quality parts in the aftermarket. I see he is back to selling kits so maybe he changed his mind.

[jeff68]

Well I thought I’d chime in with my engine combination, my experience and results with it. My engine is a 82 X 90.5 (2110cc). It has CNC / hand ported 42 X 37.5 CB 044 heads match ported intakes that were ported up to the carburetor flange. The engine uses a K10 cam, 48 Ida’s, 1 5/8 merged header, full flow oiling, 3 ½ qt. Sump, Stinger S4 ignition, all german cooling tin with compression set at 8:1. Yep 8:1. It runs fantastic, never overheats, is very responsive, no flat spots, no overheating in traffic or freeway, easy to start hot or cold, drive it anywhere on 92 Octane pump gas. My engine was built to be primarily street and hwy driven with occasional track trips and to be run on gas station pump gas.

My engine uses Carillo Porshe length rods, and a real forged 82mm crank. IMO if you use a quality crank and rods you will not have the piston side loading problems you hear some talk about. What you do get is an engine that will generate more torque throughout the rpm range if your induction system is matched and the engine is tuned properly.

The static compression is set at 8:1 and the engine runs fantastic. If my engine runs this good why do I need more compression. There is such a thing as a great running “Low Compression” Air Cooled VW performance engine. I thought about running more compression but after researching this I don’t think it’s a good idea. Do your research. Contact a fuel representative and discuss your application and ask what compression they recommend for a specific Octane. To get a little technical, any fuel has thermodynamic properties that are affected by temperature at a given pressure. Octane is a measure of a fuels resistance to burn at a given pressure and temperature. You can do things with the combustion shape and configuration to optimize the burning of the fuel but this DOES NOT have anything to do with the Octane of the fuel you are burning in that chamber. Think about that for a minute. Chamber shape and configuration DOES NOT change the thermodynamic properties of the fuel (Octane doesn’t change). Automotive engineers have been studying combustion chamber shape and configuration for a long time and if there was a magic combustion chamber design that allowed the use of lower Octane fuels with higher compression ratios believe me they would be using it as this would be FREE HORSEPOWER. If there is a head porter in a small VW shop that has found this shape / configuration they are severely short changing themselves and could be making millions working for an Automaker.

My $0.02. Do your research, talk to reputable, experienced VW engine builders about what you’re trying to do / achieve and make intelligent choices. Don’t just roll the dice and hope for the best, use your head.

[Stripped66]

[Jimmy111]

An LS7 is a totally different animal than a vw head. It has everything right going for it.
1. Spark plug in the right place and angle.
2. Well generated and directed swirl.
3. The exposed area of the combustion chamber is very small
4. Direct port fuel injection.(very important)
5. the way the intake port is designed it cools a good 50% of the exposed combustion chamber surface.
6. Exhaust port directly exits the head. very little heat gain.

And of course it is water cooled.

None of this applies to a VW head.

As Stripped66 said. The octane rating has little to do with the preignition problems. It is just an old antique cylinder head design that is not very efficient that causes all the problems.

[Stripped66]

[jeff68]

Stripped 66: I have a very thorough understanding of thermodynamics and of the chemical reaction that’s taking place in the combustion chamber. I did very well in these courses as well as applying what I learned in real world applications. Combustion chamber shape has NOTHING to do with the thermodynamic properties of a specific Octane of fuel. That’s the laws of physics talking not me. The Octane of the fuel doesn’t change in the combustion chamber. Re-read my comment(s), don’t misunderstand, and if you like, study the subject and re-educate yourself.

I worked for an automotive supplier who designed and manufactured sensors for modern automobiles, specifically, knock sensors, and we developed related engine monitoring and control technology. As previously stated, A computer controlled water cooled engine that is basically monitored and controlled by a programmed by an ECU to optimize fuel mixture & delivery, ignition timing, as well as knock sensing while running is a very different thing than a carbureted air cooled VW engine. It's is an Apples and Oranges comparison. If you want to discuss the design differences between the cylinder heads on the L89 and Chevy LS7’s and their design it might be better to do that on another forum. And really, In short even the L89 and LS7 in the Corvette are vastly different in more ways than the cylinder heads, again apples to oranges. The differences between the LS7 and the L89 go much further in depth than the cylinder heads so it’s difficult to do an apples to apples comparison by just swapping the heads. Why is it people like to bring in Chevy engine comparisons with a VW engine? I wonder what would happen if you started comparing an air-cooled VW with a small block Chevy on a Chevy performance forum, that would be interesting I'm sure.....

Don’t misunderstand my post. All I did was post my engine configuration and state that it runs fantastic with low compression. If you have success with your combination great for you, but please don’t take shots at me because you disagree. As far as my engine being cookie cutter, from what I read on this and other forums, most engines I see are running MORE compression and different cam timing so maybe they are cookie cutter combinations? I made my own decisions based on my own knowledge and experience and I have excellent results as a result of it. If it’s contrary to how you chose to do things, what’s wrong with that? I don’t know what this “grow a pair” comment is all about but I’m pretty sure I have a pair and I “know what’s going on”. I do what I think is best, am not afraid to make my own decisions, stand behind them, and voice my opinions for people to use as they may . My combination works and I’m proud of it. Is it ground breaking - no, has it been done before- sure, but it works really well and that was my other point.

[jeff68]

Stripped 66: Were you talking about the Chevy L89 head or L98? In one post you referenced the L89 and the other the L98.

[Stripped66]

[mightymouse]

[mightymouse]

[jeff68]

My engine already made 172 horsepower set up the way it is. Like I explained, it runs fantastic the way it is. I'm completely aware of the differences in dynamic and static compression. I'm sure your engine will or does run on 91 Octane and so does mine. Take care.

[mightymouse]

[Stripped66]