Wafler

Stock B20Z bottom end
Stock B16A head
Possibly my old Skunk2 Stage1 cams
ITR valvetrain(with valves)
AEBS intake manifold, J's intake, Vibrant 4-2-1 Jpec race header, 2.5" custom exhaust, no cat...

- Highest recommended revving?

It will hit around 10:1 compression with stock pistons and the B16A head or possibly up to 10.4:1 with a -thin- headgasket. Anyway, how disappointed will I get, building this budget setup for starters? (Hondata tuning on the road is likely to happen...)

Yes, I know this isn't the professional way of doing things but I am wondering what I might expect with this setup. The reason I am asking is that I don't have a shitload of money and was wondering if this "budget" setup would be fine - I'm sure others would consider this if the cost can be held at a minimum!

Post comments or suggestions to setup please.


Modified by Wafler at 12:02 PM 7/8/2005

jfranknbeans

Unless you have the intake manifold and custom header and exhaust, forget that and focus on the important parts... the engine. You are planning to mount a b16 head on a b20 block.
1. vtec wants the higher rpms. Buy a set of probe pistons and rods. $650 ?
2. a b20=84mm bore b16=81mm bore; Have DPR do some headwork and open up the chamber so the chamber will match the bore. I got a stage 5 and it is beautiful !
The horsepower you will gain from the rods, pistons, and headwork will more than make up for the gains from an intake manifold, intake, and header. Then you can buy that stuff later.
This way you will have a GOOD budget engine that will be strong and powerful. If your worried about the cost, do what I did, live off ramen noodles for a couple months. lol

Wafler

Thanks for the interest

I have everything but the block you see. The materials for exhaust will cost me $0 and I will do the work myself. Header and im is in house.

1. <U>rpms </U> : how much rpm will the B20 take over an extended period of time?
<U>rods/pistons </U> : what compression to use with my Skunk2Stage1's?

2. This obviously seems important as the head and block will not match. How important
is it? Having someone do headwork seems to be budget-unfriendly...

zman

well my buddy has (i should more say had) a stock b20 with ITR cams, mugen header and 2.5" exhaust (no cat) tuned with hondata making 205whp and 150tq. Mind you he doesn't rev past 7500rpm b/c he's not using arp rod bolts. But it pulls like hell, he's never run it on the track and he's using crappy all-season tires on 14" steelies so he can't launch it for ****. And he just spun a rod bearing, but he didn't use a vtec oil pump or water pump for that matter.
I would say bare minimum get a vtec water pump it has 22 teeth so it spins slower. But if you use a vtec water pump you need a gsr/itr timing belt.
You will also need to machine the dowel pin holes in the head to fit the larger b20 dowel pins, or get the trick GE conversion ones that are smaller on the top than bottom. You will need to get a vtec oil feed line, plug the vtec solenoid oil feed hole in the head, and mod the headgasket.....might as well get ARP head studs (gsr/itr ones) while you are at it...you need new head bolts anyways so you might as well spring for the studs....its worth it.

mmuller

weak link are stock rod bolts.

non-VTEC

7500rpm max would be alright..........8000rpm would be OK once and a while but it will deffinatly be pushing the limits of those rod bolts.

Wafler

Thanks for the good answers

Now, I got the dowels under control and the oil feed so this seems worthwhile!

Use the ITR timing belt you say? Does the B18 and the B20 have the same deck height then? I will also be using both water pump and oil pump from ITR.

The thing concerning me most is the difference in the bore of the B20 block and the B16 head. I am fully capable of machining this out myself - though I'm uncertain of the importance of this operation. And this will increase cc in the combustion chamber yes? Which again leads to a lower compression. How much will this decrease in compression compare to not doing the machining on the head(pros and cons)?

Keep these good comments coming guys, this thread seems to become really informative


Modified by Wafler at 3:04 AM 7/9/2005


Modified by Wafler at 3:06 AM 7/9/2005

Professor15

i say leave the block internals stock and just replace the rodbolts, oil pump and water pump and anything else that you feel you want to replace in order to make the car safe. But it makes no sense to get rods and pistons when you will have stock sleeves. I say get valvetrain with buddyclub 3+ which are none to make more mid-range power, a GOOD quality header, DTR,smsp, rmf, anr an exhaust and strap it on a dyno and tune. If you have any more money get a valvejob.

Wafler

Bare in mind I am trying to keep this a budget buildup so if we stick to the rod bolts and vtec pump gear we'll be good right? Perhaps upping the compression while we're at with reasonably priced pistons? How high in comp are we thinking?

Any comments on using ITR/GSR timing belt? B18/B20 = same height block?

Then there is the compression issue and the bowl work? I suppose a motor with compression in the 9.x:1 range won't make great power?

mmuller

keep in mind that when you install the arp rod bolts they will require different torque settings; wich will cause the rod end to egg shape.

zman

also keep in mind that you have to take your rods to a machine shop to have them put in your rod bolts.
Yes the b20 and b18 have the same deck height...the pretty much have the same everything except pistons....b20 is 84mm and b18 is 81mm....the crank, rods, block are all the same.
If you wanna up the compression a bit get your head milled....its cheaper than gettin new pistons. But be careful with how much you mill b/c the valve reliefs on b20's aren't the deepest.
If you use the ITR/GSR water pump (which you say you are) use the GSR/ITR timing belt. But if you are using the b18/b20 water pump then you have to use the b18/b20 timing belt.
My buddy's stock block, stock head with ITR cams, tuned with hondata made 205whp....so stock compression will still make good power....but imagine what he would have made with say a 11.5:1 CR....this is the CR i wish to obtain on my b20vtec build (in the process of rebuilding my buddy's block).

mmuller

i would think about claying the motor before milling the head at all...valve reliefs are small

Verbal Intercourse

iTrader: (1)

Don't the BC 3's start to drop off after 7500 rpm?

jfranknbeans

Ok. For rpms. Three things to consider.
a. stock = low c.r.
b. 84 bore compared to 81 bore of b18 = heavier pistons = more stress on rod bolts at high rpms
c. forged pistons (with hollow dome)= much lighter than stock = less stress on rod bolts at high rpm
Yes chamber work will lower cc's, but pistons with higher c.r. will make up for it.
Since you are only using S2 stage 1 c.r. is not as important than if you were going with bigger cams

Wafler

So fixing the chambers, buying pistons which gives say 11:1 cr and new rodbolts would give me a good starting point right? This can be done without using a shitload of money I guess...

jdmotorsports

hey, what timing belt you use? the b20 or a b18c/b16a-b?

Wafler

ITR(B18C5/6) because of the use of ITR pumpgear


Modified by Wafler at 12:58 PM 7/19/2005

iakona

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mmuller &raquo;</TD></TR><TR><TD CLASS="quote">keep in mind that when you install the arp rod bolts they will require different torque settings; wich will cause the rod end to egg shape.
</TD></TR></TABLE>
so how would you put arp rod bolts on a stock rod?

(p.s. -- i'm not hijacking, i'm doing the same build you are except b18a)

jdmotorsports

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Wafler &raquo;</TD></TR><TR><TD CLASS="quote">ITR(B18C5/6) because of the use of ITR pumpgear
</TD></TR></TABLE>

the itr waterpump is a different gear then a b20 waterpump? hmmm.

goforbroke

With skunk2 stage 1's you shouldn't be revving to like 8000-8200rpm. Considering you already had the cams in your car before you know where they stop making power. Theirs no need to rev the **** out of the motor if stops making power way a lot earlier in the powerband. Anything around 10.1 to 11.1 compression is "great" for those cams. You don't need any crazy high compression for those cams to make power.