why is my engine not powerful?

[bmw2101]

For the rallies i do , i have to either use the standard inlet manifold for injection for that engine type, or 2 barrels of carbs. So i cant use a pair of 48's but i can use one single 48. I cant turbo

My engine is the following spec;

B230A
3cc dish in pistons
standard head gasket
531 head ported roger upperton racing, not a volvo specialist but knows how not to kill power
solid valve shims
44/38 valves
kl racing t5 camshaft [advertised at 300 degs but its more like 280]
head is 45cc volume [3mm skim from head]
tubular exhaust manifold from norway, simular to the kl racing one, with 63mm exhaust
lh2.4 type inlet with 63mm throttle housing,
t5 injectors i think they are
microsquirt ecu

car has just been mapped again. with a home ported 531 with standard valves, t5 camshaft it did 160 bhp, today it made exactly the same power! I was expecting more like 180 bhp.

Where is the restriction, i have ported the inlet some, and fitted the bigger housing to it, but is it the manifold that is making the restriction? Or is that about right power for that spec?

What am i missing?


The only time it made more power was when i fitted the cast manifold to it and it did 166.

For a 2.3 engine , it dosnt feel right, mid range is a bit fluffy at times, but it does go ok when its reving.

thanks, any ideas?

[Matti johansson]

Is it highrevving for that cam?

Whats the lobecenterline? Normalt 104deg is around normal for Volvo.

What compression ratio do you have?

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[Matti johansson]

Can you use special manifold and 1 Weber 55?

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[Jens Gustavsson]

you shold make 220-230hp med en bra kamaxel och topp med ett custom 2 ports insug och en holley 2 ports förgasare.

men det kräver en del tid och tuning för att komma dit.

enklast är nog att skippa hela insprutnings systemet det insuget är inte bra för hög sugmotoreffekt.

vilket bränsle är godkänt i den klassen?

mvh jens

[bmw2101]

you shold make 220-230hp med en bra kamaxel och topp med ett custom 2 ports insug och en holley 2 ports förgasare.

men det kräver en del tid och tuning för att komma dit.

enklast är nog att skippa hela insprutnings systemet det insuget är inte bra för hög sugmotoreffekt.

vilket bränsle är godkänt i den klassen?

mvh jens

thankyou for the reply. With the inlet i have, will it restrict the engine to about 160 bhp? is that the problem i have? I want to stay with injection. as long as it look standard itll be ok, but the rules say either 2 barrels of cars so like 2x su or one side draft webber for example.


oh fuel wise i can use like 99 is the common one here. it has to be pump fuel as the rally is on the road at night. may do like 100 or more miles.

[bmw2101]

Is it highrevving for that cam?

Whats the lobecenterline? Normalt 104deg is around normal for Volvo.

What compression ratio do you have?

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i think static my compression is 11:1, but ill have to do the calcs again. cam center is 106 it says on the web site.

i can use a weber but i want to stay with injection if i can.

[Jens Gustavsson]

det är inte 100% insugets fel. hela konceptet måste lira ihop.

berätta mer om bromsningen ,lamda target, spridare, regulatorer, tändsystem och hur tändkurvan ser ut mm.

bild på diagramet på vrid och effekt mm.

mvh jens

[Matti johansson]

Compression will certainly bump up the numbers youre too low!

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[Hasse Bus]

Is it highrevving for that cam?

Whats the lobecenterline? Normalt 104deg is around normal for Volvo.

What compression ratio do you have?

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i think static my compression is 11:1, but ill have to do the calcs again. cam center is 106 it says on the web site.

i can use a weber but i want to stay with injection if i can.

Så här står det på KL: sida om kammen.
KLR T5 Passar vassare gatmotorer med högre komp utan Turbo och Turbomotorer med riktigt hög effekt och stor Turbo och prog sput/Tändning. Ej lämplig för för vardagsbilen till och från jobbet.
Kamaxlarna är slipade på nya ämnen (vi behöver Ej någon gammal kamaxel i byte)


Dur på körspel 300 grader
Kamlyft 12,9mm
Nockvinkel 108 grader
TDC lyft ca 4,5mm
Ventilspel 0,35mm
Fördelarspår på kamaxel: Ja
Behövs Laschcaps: Ja, 4mm rekomenderas
Passar till original ventiltryckare

TDC lyft är angivet med ventilspel och ställs in på följande vis.
Ställ motorn med kolven i toppläge (avgas håller på att stänga och insug håller på att öppna).
Insugningsventilen skall då öppna angivet värde.

Jag kan inte så mycket, men är inte lobseparationen 108gr avsedd för turbomotor snarare än sugmotor.
@Jens @Matti @Erland

[quattro]

I agree with Matti.
I used this site https://www.summitracing.com/newsandeve ... calculator to calculate your compression ratio based on standard B230 bore and stroke, plus the 3 cc in the pistons and 45 cc in the combustion chambers. I assumed a standard head gasket was 1,9 mm thick and that the pistons protrude 0,3 mm above the block surface. That came to 11.2:1

But the dynamic compression ratio will suffer from the numbers of the cam. Your inlet valve will close at 78 degrees after BDC, your exhaust valve will open 78 degrees before BDC and the overlap will be 80 degrees. That's a lot. It's a cam for high compression and high revs.

But your engine has breathing restrictions so it it will need higher compression than an engine with a full race head and/or a milder cam. It is starved on air. But it has lower compression ratio - not higher.

[bmw2101]

thankyou so much for the replies, this is gold info to me!


so what do i do? i need more power out of it really, in the uk to get parts from sweden its quite expensive now. Is it the camshaft all along and the inlet that is the problem? I could use a K jet type with injectors into it. I can get a H cam easily here in the uk though.

I need low pulling power, not so many revs, from say 3k-6500 would be ideal. It has a 5.0:1 diff, and a 6 speed is200 box in it. works well, just needs more power. Ideally like 180bhp

[quattro]

I do not have any experience with the Volvo 230 engine, but a lot with the older B20. I built and rallied them back in the late 70-ties.
The B230 is cross flow which the B20 isn't. That makes them a bit different, but drawing on my B20 experience (for what it's worth), I would say you should reduce both the lobe separation and the total duration. That means closing the inlet valve earlier which will increase the mid range grunt.
The KL Racing B230 H-cam has 272 degrees duration and 109 degree lobe separation. Inlet opens 27 degrees before TDC and closes 65 degrees after BDC. I expect your car with that cam would seem "mild mannered" and too weak.

With the B20, going from the K-cam (277 duration/111 lobe separation, same type of cam as the B230-H) to the R-cam (287 duration/100,5 lobe separation) turned a mild mannered street sports engine into a full blown race engine. A bit difficult to drive below 2500 but much stronger mid range and topping out at 7500. Worked well with both Webers and SUs but Weber 48s were the best for power. The engine sounded a lot different as well, compared to the wide lobe separation K-cam. With the R-cam the inlet opened at 42 degrees before TDC and closed 65 degrees after BDC. It's like the B230-T5 on the inlet opening and like the B230-H on the closing.

Did they test advancing the cam when you had it on the rolling road - or did they just check that the degrees corresponded with the install instructions?? Advancing the cam as Erland recommended normally increases mid range. If it has 300 degrees at ? what lift and 108 degrees of lobe separation it should probably put it in at 104 Intake and 112 exhaust. That is 4 degrees advanced.
It would be the easiest and cheapest change to try - if it hasn't been done.
Another thing to think about is that with restrictive carbs and inlet manifold you do not want too large inlet ports as that lowers the air speed which hurts the mid range.

[bmw2101]

thanks again. yes on the rolling road we moved the cam 4 degs forward and back to see if i had timed it in properly and it didnt make much difference, Chris the tuner said that the cam was in the right place.

The port size, the guy who did the head roger upperton isnt a volvo specialist but he does build bike engines, he has some world speed records!! He said, he didnt do that much to it really, blended in and put the bigger valves in. Im sure he said the exhaust port was big enough as is, what ever he did, he has good experience , but he said itll make good power. Im sure he said the cam to look at wasnt that aggressive, but maybe after looking at bike cams it isnt.

Before i had this head done, i had a 531 that i had the t5 cam in, standard valves, i ported it myself and did too much work on the exhaust side of it, Russ tyler here said i had messed it up ! lol But the thing is, this head made -1 bhp over what i have now.

So cam , and the inlet are the problem then? I think im going to try the k jet inlet too with some injectors in it, i know Kyle Eisenbach runs this type on manifold with a cast exhaust manifold and has 180+ bhp, which is where i want to be! I think he has a enem cam in it.







i should have posted these pics first time, this was the recent runs on the rolling road.

[quattro]

So cam, and the inlet are the problem then?
Probably - at least the head does not seem to be a problem at this stage.

I came across this short video showing start-up of Kyle Eisenbachs engine 2017, with his comments. https://www.youtube.com/shorts/0wGhKW_Pipk
He runs an Enem C2 camshaft which spec-wise is a significant step away from the T5 in the direction of the old B20 R-cam. The C2 has a duration of 292 degrees with inlet opening at 43 and closing at 69. Lobe separation is 103. Lift 13,9 (1 mm more than the T5). It will increase mid-range torque over the T5. The earlier closing of the inlet will also increase dynamic compression which would be beneficial to your engine. https://enem.se/produkter.asp Go to page 2 and scroll down half a page.
If it's installed in a slightly advanced position mid-range should increase still a little bit more.

The inlet looks like something you keep only due to regulations and because everything else is worse...

Here's another vid from Kyles YT channel with an incar view from Portland International Raceway 2021. https://www.youtube.com/watch?v=uknTW20Ea8g
Pit stop during a race https://www.youtube.com/watch?v=hVXRAsPa77w

[bmw2101]

right ok, ive been talking to a few people on facebook, one is Scimec motor in Norway. He spent a fair bit of time asking about my engine, and i remembered i had the flow for my head



the bottom two rows, test 6 is my standard head, and test 7 is my modded head. Now its not that much different from standard. So My head is not much good, my cam he says lacks low end punch which is what i want, and the inlet is no good either.

So i either buy a head done from someone more than likely Scimec, or leave it as it is. For that extra power its "a lot" of money. DOnt forget also in the uk i have to pay for postage, but i know its right then.

Dont know what to do!