K or VX cam in a NA B230F? (2010 bump)

dl242gt said:

What I did for a street performance head is spend the money on improving the flow through the head with the existing valves. Cleaning up the flow path, a valve job, and stock size valves gave a good flowing head that still had plenty of low rpm torque. Great for a fun street engine.

Click to expand...

Yeah that is likely the way I will go based on the previous discussion between you and me. I just have to man up and pull out my wallet. That plus KG still doesn't have their 004 cam in stock so I'll probably end up with a K cam.

Speaking of which, if anyone has a K cam...

Fred Gwynne said:

My plan now is for just a valve grind in addition to the head being shaved down and the larger cam which will likely be a used K cam. I imagine that larger valves installed would cost considerably more than just having a re-grind but if bigger valves will add a large enough improvement in power, considering the price, then I may be interested.

I had a shop in CT recommended to me for this sort of work so I'll have to get in touch with them for a price. If the bigger valves cost more than an extra 500 bucks then I will likely pass. Any chance bigger valves may not be a great idea because I have an auto transmission? I think there is something about how more air can pass through a larger tube but if the tube is too large then the air may pass more slowly than is ideal.

Heck if my 240 rots away in a few years then the modified head could just be stuck onto my next 240.

I am completely fine using the 91 octane over here. My primary car is a late model VW with decent gas mileage while running 87 octane.

Click to expand...

Larger valves definitely cost more as you have to buy the parts, then there is the additional machining/porting time into opening up the seats and bowls under them to better match. I can't say for certain if the larger valves will hurt things off idle, but I will say that my car with the bigger valves and slightly shaved had a TON of torque at low rpm with only a B cam, and even the K cam when it was advanced. The more flow the head does, the smaller your camshaft needs to be for the same amount of total flow. A smaller camshaft behaves better at low rpm than a larger one, but bigger is not always better because you want the velocity to stay high.

If you're up for spending a little more on a camshaft, there is also AGAP.se, ENEM(V16 is likely an awesome DD camshaft), Kyrkmotorsport, Folkraceshop and more. But, the K cam is a good cam for a mild upgrade, for sure!

I think you might have read everything I've said recently already, but just in case you missed something, click my profile and take a look at my recent posts in the various threads I've recently brought back to life.

The next head setup I want to try is a 531 with a V16T in it. Will use the yoshifab beehive springs. I want to put that on a B21FT with plenty of boost. I do wish now that I would have bought a n/a version V16 as well.

dl242gt said:

The next head setup I want to try is a 531 with a V16T in it. Will use the yoshifab beehive springs. I want to put that on a B21FT with plenty of boost. I do wish now that I would have bought a n/a version V16 as well.

Click to expand...

I look forward to hearing about it! I think thelostartof used to run or still runs a V16T, but I?m not sure who else does. Don?t you already have a 405 head and V15T on your b21ft? Is it shaved any and with a thinner headgasket and/or decked block?

Here is a interesting comparison between an IPD and a VX3 cam. He even mentions cam wear.

http://people.physics.anu.edu.au/~amh110/Camshaft/volvo_camshafts.htm

klr142 said:

I look forward to hearing about it! I think thelostartof used to run or still runs a V16T, but I?m not sure who else does. Don?t you already have a 405 head and V15T on your b21ft? Is it shaved any and with a thinner headgasket and/or decked block?

Click to expand...

Good memory! It is only machined enough to clean the surface of the 405 because it's a big coolant passage head and I didn't want to warp it or damage it. So I haven't gone over about 14psi with it. Well I tried not to. lol.

The 531 has 38mm exhaust valves with all the same flow work as the 405 and it's scp. So should handle the boost better. But I will need efi for it since it's not machined for kjet injectors like the 405. So I have a bit of work to do yet.

Good afternoon,

This Sunday I plan to drop my '87 245 at a shop. They will remove the head and measure the piston height. Once they give me the height I will decide what compressed thickness head gasket to buy. The head will be brought down to a machinist who will do a 3 angle valve job and mill the head down a bit. 0.03" seems appropriate. Thoughts about that? I want a legitimate increase in power but I also don't want a ticking time bomb. Once it gets back to the shop a KG Trimming 004 camshaft (pretty much a k-cam) will be installed along with an adjustable cam gear. I have faith in the shop tuning the engine properly. My biggest concern is the piston height. Is there a good recommendation for how much piston squish clearance there should be? Thanks for your thoughts! I'll be sure to post the piston height when I know it. This is going to cost me a pretty penny so I don't want to blow it.

Thanks again!

I would go 0.040" mill (1mm), that and a thin head gasket will get you around 10.2:1 General rule for piston-to-head clearance is 0.035-0.040". If you can't precisely measure the piston depth at TDC get the 0.036" Cometic head gasket and call it done.

shoestring said:

I would go 0.040" mill (1mm), that and a thin head gasket will get you around 10.2:1 General rule for piston-to-head clearance is 0.035-0.040". If you can't precisely measure the piston depth at TDC get the 0.036" Cometic head gasket and call it done.

Click to expand...

Thanks for your thoughts! Very much appreciated. I've been tempted to just buy a "thinner than usual" cometic gasket simply because the shop may not want my car taking up space while we wait for a 0.xx" gasket.

Edit: Looking at the estimated shipping dates from jegs.com, summitracing.com and straight from Cometic I'm starting to think that I ought to just order the 0.036" gasket now.

I agree with the above. There will be nothing ticking time bomb about it and it should be a nice upgrade from stock without doing anything else. You probably won't need to run premium gas, either, but time will tell.

klr142 said:

I agree with the above. There will be nothing ticking time bomb about it and it should be a nice upgrade from stock without doing anything else. You probably won't need to run premium gas, either, but time will tell.

Click to expand...

Thanks, I'll go for it.

I'm at 9.8:1 with a V cam and run 87. Top Tier, of course. I still have enough headroom to do the +3 ign mod in the EZ116K, so you should be fine.

I've got the european b230k engine with 10.3:1, which also has a kg004 cam now, stock HG and converted to LH, I'm using a LH 951 ecu and the 169 EZK module both from a b230f. It's idle is a bit rough, but the setup has been reliable for many trackdays on euro95 (regular), and at elevation I've also used euro98 (premium) which improved the low end somewhat.

I would add the adjustable cam sprocket and I would suggest a set of chips from sbabbs. You'll want a fuel ecu and an ezk that are chipped. Probably some slightly larger injectors, too.

The factory ignition timing may actually be sufficient with the increased compression. The only way to really dial it in is to strap it down on a dyno and tune it yourself. The off the shelf chips that Simon(sbabbs) has, if I remember correctly, increase ignition timing across the board and may be too much in certain circumstances. I can't get away with more than stock levels of ignition advance on my current setup around 2000rpm(H cam with a .036" gasket and around .033 off the head, if I remember correctly).

The stock fueling is a bit wonky and could be improved with chips, but the factory stuff is actually ok once it's learned a bit for the most part. The high rpm stuff where it's super rich from the get go is hard to lean out unless you drive at really high rpm(4000-5500rpm) at light load so that it stays in closed loop. I've done it before, but it's a bit of a silly process.

An adjustable cam timing gear is definitely a good idea as you'll likely want to run it 4-6? advanced to bring some torque back under 3000rpm. This will put the camshaft timing back closer to straight up or advanced a little after accounting for the reduced distance between the camshaft and the crank which retards camshaft/valve timing about a degree per .010".

Hi folks,

The shop measured the piston height on the motor. All four pistons came up past the deck from .004" to .007" and the original head gasket compresses down to about .050".

I purchased a .036" compressed gasket so I think that the tightest squish will be .036" - .007" = .029" after the gasket is installed.

Is that pretty good? Or is that too short a distance? I had been assuming that the pistons would be below the deck at TDC but I guess not.

Does that still make .04" milled off the head seem alright? Valve interference? As always your thoughts are greatly appreciated!

I'm going to drive the head down to the machine shop this Wednesday.

It's a little snug but I wouldn't sweat it. I assume you've got new rod bearings? If not, I'd at least check them to make sure they're in spec.

You're still in the ballpark for 10.2-10.25:1 static compression ratio. Using the 10.25 number with the VX cam, I get a dynamic compression ratio of 7.55:1. With the K, it drops to 7.31:1. With this number on the VX and 87 octane gasoline, there may be certain circumstances where you experience detonation. I also think it would be a simple remedy by retarding timing a hair or maybe just switching gasolines, not necessarily grade but maybe just brand.

Unfortunately I did not get new rod bearings. I should have thought about that. I personally don't mind running a higher octane fuel if needed. My primary concern is a piston hitting a valve. Thanks for your help and comments. Very much appreciated.

You're pretty far from having a piston hitting a valve under normal operating conditions, even at max retard or advance on a timing gear. If you do have a timing belt break, there will be interference though.

I run a very similar setup, but with a B cam. It will run on regular without any signs of donation (audible or on spark plugs), but it gets better MPGs and more power with premium fuel.

It'll be just fine, as they say. I look forward to hearing how it goes when you get it back.

For reference, how much is shaved off of your race car's head that you're running with the K cam currently, shoestring?