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2.0L 914 engine build recommendation spec's for street use

Posted: Fri Aug 14, 2015 10:26 am
by mcdragracer
Building a 2.0L 914 with 2.0L bus heads, going into a street buggy.
Crank will be counter weighted with a lightened flywheel, brothers is doing the head rebuild with just a mild
port job with one step up bigger size intake and exh valves, using solid shaft rockers (1.7L) with 911 adjusters, chromolly
push rods/solid spacers, straight cuts, about 9:1 compression, need recommendation on cam and would i need a HP pressure plate? I don't think I would need one.
It's for my friend, he won't be drag racing it around but will put his foot into it when he wants to, which could be often, also will be running 45 Dells,
looking for just a real good street cam with a good idle and all around performance from idle to high RPM and or maybe from mid
to high RPM.

Re: 2.0L 914 engine build recommendation spec's for street u

Posted: Fri Aug 14, 2015 2:44 pm
by Piledriver
The 2L Bus head castings do not flow well without a lot of port work.
If you are using a 228mm FW/pressure plate and a 091 trans, you can probably get away with the std pressure plate.

Web 86a or 494 works well in that CR range, tighter lobe centers bring it "on the cam" sooner and harder, and makes for higher dynamic CR. A good exhaust is required for the rest of the setup to work.
A counterweighted crank is not required on a T4, just a good balance job.

If you want higher RPMs, a Web 163/86b is a great all round choice, get 102-104LC for ~9:1 CR.
Dual springs required for 163/86b, and recommended for the 494.

Use it with the proper SLR reground (new) coated lifters, aircooled.net sells the combo, strongly suggested.

The lifters from webcam are pot luck (brand and quality varies)

Use with a high zddp/zero detergent break in oil like brad penns break in oil or valvoline VR1 "not street legal".
(many shops that build a lot of engines filter and reuse break in oil)
After, regular Brad Penn racing oil, Rotella T6 syn (or even HD30 or HD40) or Valvoline VR1 are commonly available high zddp choices.

I have successfully used Rotella HD30 and std VR1 for break in on milder profiles with dual springs. YMMV.
The 494 is a more aggressive profile, as is the 163.

Re: 2.0L 914 engine build recommendation spec's for street u

Posted: Fri Aug 14, 2015 5:36 pm
by sideshow
The web 86, standard aftermarket cam gear, stock crank is great, and what trans axle is in the buggy?
You may have to go to a HD cover if you are not using the normal 210-215-228 they came with, but with heavy covers driving enjoyment generally decreases. Stock covers offer great feel and enough clamping for 1 ton truck.

Re: 2.0L 914 engine build recommendation spec's for street u

Posted: Sat Aug 15, 2015 3:32 am
by mcdragracer
Great information, I measured the flywheel at 8 3/4 in should be right at the 228, I suggested he use the stock crank,
but he really wants the counter weight and the flywheel lightened, i was thinking of the 86a and I will look into the SLR lifters,
I've heard good things about them, yes everything is gonna be balanced.
And I believe he is running the 6 rib stock bus trans, the motor he bought came with the bus heads, so were stuck with them,
sending them to brothers to have them done with there 1st stage port and over size valve job.
I have the brad penn break in oil, also anyone know the ratio on the rockers from the 1.7L to the 2.0L if they are the same
and where i might be able to find some and I'm thinking the time and money we will have in the rockers if were better off to go ratio roller tippped rockers? and one other thing, could i reuse the stock oil pump or is it recommended to go with the T.1 with the conversion that I've seen.
I hate to sound like a newby, but I'm not, I've built 100's of stock and HP T.1, a few turbo's, and a bunch of stock T.4/914 and water cooled vanagon motor's, worked at an old aircooled shop for years, just never delt with the HP end of the T.4

Re: 2.0L 914 engine build recommendation spec's for street u

Posted: Sat Aug 15, 2015 7:17 am
by sideshow
You can't lighten that flywheel, not that it matter much. Rockers are the same ratio, and I just used the nicest stock pump sourced from random cores. Unless you wanted to change the outlet side of the pump or didn't have one I don't see the point of a type-1 pump.

Re: 2.0L 914 engine build recommendation spec's for street u

Posted: Sat Aug 15, 2015 10:18 am
by mcdragracer
Gotcha, I have the stock pump, I'll just take it apart, clean it and change the o-ring, any kind of guess on HP
range for this set up?

Re: 2.0L 914 engine build recommendation spec's for street u

Posted: Sat Aug 15, 2015 1:41 pm
by Piledriver
The 228 is pretty much all clutch with a ring gear, its typically ~14 lbs already.

Some of the Vanagon units have a thick ring behind the ring gear that can be turned off w/o weakening the flywheel, and that's the most important place to lose weight. Do not turn it down past the root of the teeth on the ring gear.
(Would be best left alone, really)

Do not thin out the area behind the friction surface, it matters for strength and doesn't matter much for rotating inertia.

Too many variables to guess HP beyond a WAG, but 130-140 is probably reasonable.

Re: 2.0L 914 engine build recommendation spec's for street u

Posted: Sat Aug 15, 2015 3:13 pm
by mcdragracer
Yeah, I think I'll leave the flywheel alone and use a stock sach's clutch kit,the HP power I was thinking the same around in that range. One other thing, it was missing the windage tray, having a hard time finding one, is it nesassary in this build, I've read some different things on using it or not, were not circle track racing and not drag racing it.

Re: 2.0L 914 engine build recommendation spec's for street u

Posted: Sat Aug 15, 2015 7:49 pm
by Piledriver
Skip the windage tray, it doesn't work well without mods.

Do consider going dry sump if you plan on carving down canyons.