High Revving B16 Advice


forestfighter

forestfighter

ZR-TEC RALLY TEAM
Joined
Jun 13, 2008
Messages
315
Evening folks,

I'm having a B16 engine built for my rally car. Current spec is:-

B16A block all balanced with polished crank, Eagle rods, 81.5mmWossner high comp pistons (estimate 13.5:1 ish depending on HG). Genuine oil pump and belts. I'm using a standard but ported B16B cylinder head with Titan ITB's. Here's my question....

With the high compression, throttle bodies and fully balanced bottom end i was aiming to rev it hard and have been told the B16B cams would be good to do so with... Trouble is, what are the B16B springs and retainers good for rev wise or am i best upgrading them? In an ideal world i would put some beefier cams in it but budget is getting tight with all the purchases i've already made... Plus i wanted to retain some decent driveability with the B cams... What's best to go for if it's crucial i do so?

I heard the B16 could rev to 10k easily enough with a strong bottom end. Revs isn't everything i'm aiming for but all the better with rallying really...

Advice would be great please!

Thank you.

John
 
Are you sure about the compression ratio? Have you the specs of those pistons?

B16B cams are not going to carry power past 9000rpm! With all that compression and those cams you will probably peak power around 8000rpm! If your calculations on static compression are correct you could run Pro 2 cams on that engine.

Your right revs isn't everything, a fat torque curve will be much more useful for rallying.
 
Sorry, typo... 12.5:1 compression yield for the pistons. Head has been skimmed quite far and a thin gasket will be used. So say if 9k is the limit for those cams, what about the springs and retainers? 9k too?

At the end of the day, we'll stop once she stops making good power, even if it's still at 8600rpm - we're not just trying to hit a rev figure. The engine has to be dry built once more for clearance so this was the last thing to look at before it's sealed. If it's an obvious upgrade to make, i'll make it.

Thanks again!
 
For b16b cams? Stock type r valve springs will be fine. For Skunk2 Pro 2 cams you will want to use there Pro series valve springs and retainers.
 
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Kind of hard to get good torque numbers from a b16 dont you think..
 
forestfighter said:
Thank you. I'm guessing with this sort of spec, 200hp would be achievable?
Click to expand...

With b16b cams, probably not unless it is a "happy" dyno. With Pro 2's yes it should make +200bhp. What kind of piston to head clearance are you ending up with?
 
oscarsayco said:
Kind of hard to get good torque numbers from a b16 dont you think..
Click to expand...

Depends what you classify as "good torque" We've seen better than average b18 torque figures from some built b16 engines.
 
Consider buying a close gear kit / final drive, that would benefit a lot your build.

As @Vtec6000 said, 200 hp is achievable with skunk2 pro cams, considering you find a good tuner and you're going to run a fully programmable ecu.
 
I'm not sure on the piston to valve clearance. The head has been skimmed quite far to raise things as much as possible - as i say i have a chap building it for me.

The car uses Hondata S300 so will be mapped on our dyno at work. I have a full Gear-X gear kit with KAAZ plate diff in it. Everything is fairly well sorted, video below for you with a near standard B16A last year.

 
Vtec6000 said:
Your right revs isn't everything, a fat torque curve will be much more useful for rallying.
Click to expand...

It's a 1600cc engine, it's never going to do better than about 140lbft, revs is definitely the way to go on this engine. Revs and short gearing to keep it in the power band. :agree:
 
Kozy said:
It's a 1600cc engine, it's never going to do better than about 140lbft, revs is definitely the way to go on this engine. Revs and short gearing to keep it in the power band. :agree:
Click to expand...

Lets keep things relative here! Obviously its never going to make 200 ftlb's torque but if you can produce a engine that delivers a decent overall spread of torque with a nice "fat" midrange(140-150 ftlb's) it will be more suitable for rallying than a engine that is all about top end power and not a lot going on in the midrange, that kind of engine is ideal for drag racing but for rallying not so much.
 
@forestfighter What brand ITB's are you using and do you have the specs of those? If your budget is tight I would try locate a set of used Pro series cams, even Pro 1's would produce a lot more power over the b16b cams on your engine.
 
I have some buddyclub spec4 cams, aem pulleys and supertech valve springs and retainers here I will be parting with if you're interested. All the stuff has done 180 miles in my b20, but I'm sick of it smoking so I'm parting it all out now. Everything was bought brand new.

At 12.5:1 and with itb a lad made 218hp iirc with bc4's in a b16a1.

And I'm only in Bradford too.
 
I'd second what vtec6000 said about getting even a used set of pro1's I'm useing pro1's in my engine, and it's making 145lbft at 4500 rpm, although that's b18c, the diferance in low down torque compared to oem type r cams is really noticeable pulling out of corners
 
The power band of the standard cams will effectively limit your max revs so you can stay with the existing springs. For higher revs and more power you'll want to upgrade to (say) stg2 cams at some point and it is then essential you upgrade the springs & retainers. I recommend you keep with the same manufacturer or if you want to mix & match choose your cams and use Supertech valve train parts.
 
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