Valves

Guest · Post by **Guest** » Fri Mar 07, 2003 11:14 pm

first thank you all for the information I've been gathering for months now. I need to revisit the subject of valves one more time though. I decided on 42/36 size for a little old 1911. You convinced me to open the cases so new bearings, web 86a and lifters. This is going into a dune buggy that will see street and offroad use. Some sand but mostly woods and rocky slow stuff near the Rubicon. I don't want to give up too much low end. I liked the 1.7 until it sucked a valve. Aircooled doesn't have valves this size.So the question is would I be better to go 46.5/38 or stock 1.8 size? I can get a set of 1.8 heads but wanted to put new seats in the 1.7s and use stainless valves. Is there a different source for valves someone would recommend? One other thing. Kadrons or weber/dells. Only about $125 difference but which will run better under ALL conditions? Sea level to 6000', Uphill/downhill? I'd rather drive than play with carbs to try to make it run right. Thanks, Larry

Guest · Post by **Guest** » Fri Mar 07, 2003 11:28 pm

If I use stock 1.8 size they won't be stainless. Are these any better than 1.7s in their material?

maf 914 · Post by **maf 914** » Sat Mar 08, 2003 5:48 am

For performance go with Webers/Dells. I've used Webers for years and they have always been smooth. Unfortunately I can't comment on their off-road ability or their ability to tolerate major altitude changes since I drive in the relatively flat southeastern coastal area.

Mike

Post by **Piledriver** » Sat Mar 08, 2003 7:12 am

This will sound insane, but for your application, a CIS conversion may absolutely blow away any carb setup.

(LH-Jet might be ideal, but more if a project, it would't care if you were upside down. CIS is "understandable" for most folks)

I forget, but if you are still running the pancake cooling, seriously consider it--- It isn't rocket science, and if you havent dropped the dime for the carbs, will probably cost less, esp if you have good scrounge skills, perhaps almost free.

Remember, CIS is purely mechanical, and they just added an O2 feedback tweak in the later versions to jack the fuel pressure a bit for emissions. (A good thing) It compensates for altitude,temp all by the mass of the air, measured mechanically--No brain. Nice simple system, and lots of help to be found.

Think about it...

BTW, Jake was getting like 100 lbs/ft of torque near idle RPM using CIS on one motor... not having search is a pain.

If you are building a motor strictly with off roading in mind, a Web 73 or (or 73/86) might be more in order.

Smaller/stock size valves may also be a good thing, available in one piece SS.

DO get the seats done with the reverse interlock taper.
(Are you doing them yourself?)

ciao

[This message has been edited by Piledriver (edited 03-08-2003).]

raygreenwood · Post by **raygreenwood** » Sat Mar 08, 2003 7:27 am

The 46.5 valves are too large. The stock 1.8 isfine on the intake...could be just a little larger on th exhaust. Be picky on the valve sizing. 42x37 would be good. The stock 1.8's will be stellite tips probably. Unless you get the very best stainless you can find..go with the stock 1.8's. Less stretch and harder tips.
I agreee with piledriver...cis would be nice. Ray

Guest · Post by **Guest** » Sat Mar 08, 2003 8:31 am

I am having a local machinist put in the seats. I told him about the reverse interlock. He had never used it but thinks its a good idea. He has been doing vw work for 25 years and is held in high regard in our area. The car is about 60% street driven. It looks fast but the hills around here just beat the 1600 down. Gearing is pretty close to stock with an early bus transaxle and 31" tires. I hoped the 86a would put some teeth into its bite. Would cis require less cam and how is the pump driven and timed?

Guest · Post by **Guest** » Sat Mar 08, 2003 8:39 am

Lawrence,

your order went out, BUT...The valves you ordered are T-1 valves. We only have 46.5 and 48mm intake, and 38mm exhaust for the T-4.

I am holding off on sending the valves or seats until I hear from you.

John
Aircooled.Net INc.
heres the problem on the valve order. I am glad John caught the mistake instead of just shipping what I ordered. Weren't the 2.0 914 heads 42/36? seems like someone should have those sizes.

Guest · Post by **Guest** » Sat Mar 08, 2003 12:45 pm

So I can get 38 exhaust but only 41 stock 1.8 intakes. You think 41/38 is good? For the exhaust I am planning on using the outlets from type4 heater boxes, switching #1 and 3 so the outlet is to the front of the car and splicing to a 4 into 2 type 1 glasspack setup. The one everyone sells for baja's. It seems to be pretty free flowing. To use cis could it be adapted to the djet intake? Thanks, Larry

raygreenwood · Post by **raygreenwood** » Sat Mar 08, 2003 3:18 pm

41x 38 will probably be OK. But..Look around for stock 914 2.0 intake valves. They will be 42mm. The 38mm exhaust is juuust pushing the edge of being a little large if no extensive porting or exhaust work is done. Being too large may lose a little velocity. I would consider it immediately if you had just slightly larger intake valves for better flow. Of course I have to go with what I know works well in certain situations. The 42x38 worked well in my injected 1.7 with an exhaust that flows about 10-15% better than stock..but was still stock configuration. If you can't get the 42's..use the 41's with 37 if you can get them. The 38 probably will matter very little since you probably are not using a stock exhaust...so don't worry too much if you can't get 37's. Ray

Mark the canuck · Post by **Mark the canuck** » Sat Mar 08, 2003 3:56 pm

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Piledriver:
<B>DO get the seats done with the reverse interlock taper.
(Are you doing them yourself?)

ciao

[This message has been edited by Piledriver (edited 03-08-2003).]</B><HR></BLOCKQUOTE>

Do you have a pic of these seats or a source?

Does it install different than a std. seat?

Thanks Mark

Guest · Post by **Guest** » Sat Mar 08, 2003 6:11 pm

I tried getting them from aircooled.net. I accidently ordered type1 stuff but John caught my error. He's waiting on me to decide what I want. I didn't think it would be this tough since this seemed a popular combo over the last few months of posts. How do you like the seats he sells? Are type 1 valves longer or shorter, could they be cut down and a single groove used? Larry

raygreenwood · Post by **raygreenwood** » Sat Mar 08, 2003 11:34 pm

Larry..I have used 42x38 valves..thats not bad at all. The cis uses an eletric pump. There is no timing. Cam will only affect you if you have significant valve overlap, but it can be tuned around that. CIS means continuous injecton. It injects in a constant flow. That causes two things. one great...one not so great..but not a real problem.
(1) having a constant spray...means that atomized fuel is available through the entire intake valve opening/closing cycle.Thats excellent! The minor drawback, is that it is also injecting when the valves are closed. What keeps this thing from running rich is that fact that what is being delivered while the valve is open...is really about 50% less than what would be required to be delivered on pulsed injection. The balance is drawn from what is hanging around from the out of cycle injection period.
Considerng that almost all Electronic injections finish their pulses before the valve cycle is finished...or inject right before...or out of sequence in the case of non-sequential injection, the amount of properly atomized fuel that enters the cylinder on the open valve cycle when CIS is properly tuned....is very close to what you get on electronic. There are also a huge # of parts variations to choose from. Except for a few puely electrical..and not electronic hook-ups...its all mechanical. I suggest using the models that use the Lambda box hook up for the oxygen sensor to control acceleration enrichment. Ray

regis101 · Post by **regis101** » Sun Mar 09, 2003 4:48 pm

My chime is now only worth 1 cent. You seem to be after more of a torque motor . Maybe keeping the valve size a little smaller might be better for low rpm velocity. If the valves get too big, there is more of a chance of head cracks at the spark plug hole. the rpm band may only need to peak at 5500 or so. Using the low gears in your tranny is going to get you over the rocks. Maybe a winch, too. You'd still be able to go 60+ down the fire roads. I dunno. This is just my opinion.

regis101 · Post by **regis101** » Sun Mar 09, 2003 4:49 pm

I also agree with the CIS if you can affort it. Stalling out on high center because of a carb can be a drag. That's where the winch comes in handy.

Guest · Post by **Guest** » Sun Mar 09, 2003 5:13 pm

we drive it around town to. Some uphill freeway onramps and people really in a hurry so I would like it to acelerate well too:-) I found manley can make valves but they don't have anything on the shelf those sizes. I guess I need to just go stock 1.8 sizes but that seems to be a shame since I'm getting seats done. Doesn't high center too bad, short wheelbase and 17 inch ground clearance in the rear with the bus tranny.