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low power output? b230a rally motor

A

Avtovaz

New member
Joined
Nov 12, 2010
I have a volvo b230A engine in my bmw compact. It has rebuilt bottom end, standard pistons etc. It has a 531 head, not modded apart from a skim, and a cometic head gasket, i think in all we took off 1.8mm. It has lh2.4, cast exhaust manifold [cant get any other in easily as its right hand drive car!], down pipes are 50mm then 63mm. The camshaft is a KL racing camshaft, its this one its 300 deg, 12.9mm lift.It has microsquirt ecu.

click here

thats the map done recently.


Now ive been told a few things, KL racing camshafts are useless, the cast manifold isnt restricting it, the lh2.4 isnt restricting it, the exhaust isnt restricting it.

So, what do i do? the cam is it too long duration for it to make good compression? is the cam just not good, or is there something im missing?


thanks
 
I may be punching above my weight, but I believe the intake could be a restriction. Are you running the stock B230F / FB / FT intake?
 
What you are missing is that the stock head won't move enough air to make any more power than what the engine is making. 160 whp is about as good as you could ever hope for with that setup. Next up the intake manifold is not that great either. Once you get a cylinder head that flows more than 160 cfm and an intake manifold that isn't a choke point you will begin seeing improvement.
 
I think it is the stock inlet, , but ive been told itll do 200 bhp ok?

That is the flywheel power, so its much less at the wheels. I cant use anything but the standard inlet, its part of the rules of the rallying i do.

The rules are along the lines of has to be 4 cylinder, for 8v can be twin choke carb or injection that was fitted to that engine as standard. ECU is free,

I thought that the 531 was this awesome head that can do all sorts? Or is it not as good as i believe?

thankls for the replies, its really hard to get good info.
 
You need like 11:1-12:1 CR to take advantage of that cam, and you can probably get away with more.
The unmodified head is a huge bottle beck, especially on the exhaust port.
The stock intake manifold is a huge bottle neck as well.

Kyles (klr142) makes like 155whp (solid torque curve!) using a b21 k-jet manifold, a very modified head, 12:1 CR, and a much larger cam than the KLR T5. The issue is the intake manifold...

A modified head , 45mm DCOEs, and a similar cam spec has been shown (time and time again) to net close to 240 crank HP.
 
Maybe you can port the head and get or port you intake manifold. I worked with a guy that had a flow bench. He would tested intake manifolds for me. It wasnt Volvo but think the same principle applies. The intake will flow at percentage of head. I ended up with a 80 percent intake flow compared with the head intake flow. So if you can get the head to flow more and get a good intake I bet it will make a huge difference. Culberro did my head on my new motor, he knows what hes talking about and does outstanding work. I would be pm him if I was you. Good luck.
 
right ok, i thought the 531 was a really good flowing head over the 530. Everyone goes on about the 531 as if it makes the massive power as it is.

my friend had a boat motor 2.5, 531 head, skimmed it right up, v cam i think he said it was, on split 50 carbs, dizzy. It was doing 156 bhp at the wheels on his escort, so when i was looking to do my engine i was expecting more as it had the cam etc. He had the cast exhaust manifold too.


I havnt said this before but my inlet is modified, its 59mm, and slightly opened up, i cant do this but no one will know.



So what shall i do? Is there more power there easily gotten?
 
The 531 has better intake ports, but the same crappy exhaust ports (that's where the major restriction is), and larger combustion chambers so the compression is lower.
A stock 531 CAN make more power than a stock 530, but a ported 531 and ported 530 are nearly identical.
 
click here

page 14 is that links right, basically its on the road at night, it says you have to keep a standard looking car, but can mod it apart from that in certain ways.

so;


18.2.Vehicle engines must have:
18.2.1.A maximum of four cylinders.
18.2.2.A maximum of two carburettor chokes (two single or one double).
18.2.3.A maximum of one camshaft per bank of cylinders.
18.2.4.Engines with more than one camshaft per bank of cylinders may be used providing that they were originally fittedwith fuel injection and that the fuel injection system complete with plenum chamber and throttle body is retained unmodified.
18.2.5.For diesel and petrol engines under 1500cc actual capacity, forced induction is permitted providing that thecomplete original induction system is retained unmodified,other than the replacement of the air filter element.
18.3.1.Fuel injection may be fitted where it was standard equipment by the manufacturer for that engine type and wherethe original plenum chamber and throttle body is retained for that engine type.



right ok the ports make sense then, adn im only at like 11:1 compression. maybe i should get another head and try again but use a 530 and go from there.
 
im in the uk, i dont think there is many of those heads here? Also, the 8v is in the car running, ts not bad as it is, just expected more and if there is more easily gotten, then ill have another go. The dcoe, you have to split them, and use only one choke, so itll cost like ?1500! i could use 2 bike cars, but again, i now think its the head not the induction
 
It's a combo of the head and induction. Sad that you can only have 1x DCOE on the engine.

The stock intake manifold is good for ~180 crank hp, that's it. The rules state you must have the same throttle body and plenum, can you replace the runners in the intake manifold with larger tubes? Can you replace the b230 intake with a k-jet intake? Can you port the intake?

The head you have is fine, it just needs the exhaust worked over, the exhaust side of the chamber unshrouded, and the head milled for 12:1+ CR.
 
If you don’t want to pull the head. Get a smaller cam with more duration on exhaust side. If your stock compression then your cam is way to big.
 
A 300? cam is not a good thing on a relatively stock motor. It is going to need a healthy boost in compression to work at all, but then the RPM range it works at is way above normal street use.
 
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