m20b25 best vaule for money

[FaragMan]

Hi everyone,
i run on stock m20b25 on my e30 325i and I want more power. but with minimum money.

I think about swap to 24v, turbo, iTb, stroker.. but I want to stay with the M20 atmo. and stroker or ITB is too expansive for me now.

So my plan is:

1. rebuilt the engine to stock (I must to do that, the engine is in a bad shape)
2. increase the compression ratio. (?! How do I know to do it right?)
3. replace camshaft 272 (or other?) + HD rockers
This camshaft is good? : is pretty cheap :)

http://www.iemotorsport.com/bmw/E30-valvetrain/m20cam272re.html

4. eBay china EXHAUST HEADER (Which one? or not?)
5. Miller ProStreet Induction Kit + w.a.r chip + new 19lb injector

How much horsepower do I get?
I would like to hear comments \ opinion\ Other ideas ...

Thanks !
Eden

[digitalcox]

A couple of quick questions:

1. What is your "minimum money" number you would be comfortable on spending
2. What more power do you expect?

[FaragMan]

1. 1500$ +- for upgrade..
2. the best I can with this money :)

:thankyou:

[FaragMan]

I have 6 Fuel Injector: Bosch BMW 0280150440 Pink Top 19lbs/hr EV1, 13641703819 from e39 528i.
Does they fit the m20?

Like this -

http://www.fiveomotorsport.com/bmw-0280150440-pink-top-13641703819

How is this setup?



Thinking if the oversize valve are necessary Or save the money for something else...?

Thanks

[jeffnhiscars]

I don't think you need oversize valves on a b25 and I think you are leaving out the cost of a machine shop to do head work

[digger]

cant rebuild much with that budget. i doubt you could do the head properly let alone an engine which is how i interpreted the OP.

i would use whatever injectors the miller chip called for to make for less headaches down the line.

i wouldn't bother with oversize valves, it takes some effort to get the best from them

[FaragMan]

I dont leave out the mahanice shop on the head, my budget (1500$ +-) is for upgrade parts only (Not including the overhaul oem parts)

digger, what please you suggest for me?

(I have 885 head)

How can I raise the compression ratio? And Is this advisable?

Thanks for comment!

[bmwmaster81]

Raising the compression is a good idea, just don't go to high.

It depends on which fuel you drive and wihich cam is or will be installed.

You should also check the valve clearance.



I would say put the money in the head and optimize it. Also optimize the intake and exhaust. Then get an chip which fits your optimized engine.



So you first have to decide which cam you want to drive. For Street something about 280° duration schould be fine.

Then measure all your clearences and see how much you can plan the head to raise CR.



But something between 10:1 or max. 10.5:1 when you have high octane fuel (and also the right pistons) should be the target.



Good working exhaust headers can help also.

[digger]

I dont leave out the mahanice shop on the head, my budget (1500$ +-) is for upgrade parts only (Not including the overhaul oem parts)

digger, what please you suggest for me?

(I have 885 head)

How can I raise the compression ratio? And Is this advisable?

Thanks for comment!

CR limit depends on the piston to valve clearance and piston to head clearance. you need to mock up to see how much clearance you will have in these areas and from there you can work out how much you can take off the block and head or use thinner gasket. i wouldnt go crazy here as there isnt a massive gain. you do want the head and piston to have about 0.035-0.040" clearance for best combustion.

are you going to do anything to the bottom end? is it a head rebuild or full rebuild?

[FaragMan]

CR limit depends on the piston to valve clearance and piston to head clearance. you need to mock up to see how much clearance you will have in these areas and from there you can work out how much you can take off the block and head or use thinner gasket. i wouldnt go crazy here as there isnt a massive gain. you do want the head and piston to have about 0.035-0.040" clearance for best combustion.

are you going to do anything to the bottom end? is it a head rebuild or full rebuild?

Thank you !
Im going to Stock new bottom end, (Rings, Bearings..)
and rebuild for upgrade the head, some Engine Management (new map on dayno), maf, 19lb injector, and camshaft+HD rocker. I also have M50 135mm rods, its ok? I must to replace the valve spring and retainers for new or it's ok to stay with my old? what more I must to know to do?

What is the best camshaft for me? :

1. bimmerheads 280/274 Duration - 415 lift

http://www.bimmerheads.com/catalog/m20-perfomance-regrind-camshaft/

2. SCHRICK Nockenwelle 284°/272°

http://www.ebay.com/itm/311561036761?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

3. IE NEWBILLET CAMSHAFT - 284°/280° - M20 ENGINE

https://www.iemotorsport.com/bmw/E30-valvetrain/IEm20cam284280.html

What s your recommendation for thinner gasket?

Thanks for everyone! :D


*(I have more Q on this post):

http://www.r3vlimited.com/board/showthread.php?t=381198

[digger]

Thank you !
Im going to Stock new bottom end, (Rings, Bearings..)
and rebuild for upgrade the head, some Engine Management (new map on dayno), maf, 19lb injector, and camshaft+HD rocker. I also have M50 135mm rods, its ok? I must to replace the valve spring and retainers for new or it's ok to stay with my old? what more I must to know to do?

What is the best camshaft for me? :

1. bimmerheads 280/274 Duration - 415 lift

http://www.bimmerheads.com/catalog/m20-perfomance-regrind-camshaft/

2. SCHRICK Nockenwelle 284°/272°

http://www.ebay.com/itm/311561036761?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

3. IE NEWBILLET CAMSHAFT - 284°/280° - M20 ENGINE

https://www.iemotorsport.com/bmw/E30-valvetrain/IEm20cam284280.html

What s your recommendation for thinner gasket?

Thanks for everyone! :D


*(I have more Q on this post):
http://www.r3vlimited.com/board/showthread.php?t=381198

bearings, rings, seals, gaskets

m50 rods are ok

depending what cam you could use new set of stock springs. stock retainers will be ok even if used as long as they check out ok

I’d look for schrick 272 or dbilas276 you don’t want too much duration as you never get the most out of it using the stock intake manifold because its too restrictive. For an extreme example ive seen 2.8L using dbilas 312 cam with bmw intake manifold make same hp as 2.8L with ITB and schrick 272. put the 312 with ITB and you get more out of it....

If you wanted to ignore my advice and go bigger the ENEM Z45 is a 280 cam which while not ideal it probably works ok with lower compression.

[FaragMan]

Thank you very much!
Really appreciate it!

[FaragMan]

I would like to help even the post above -

http://www.r3vlimited.com/board/showthread.php?t=381198