1911 build (need advice)

[evernon]

Hi all,

I have a TIV torn down & intend to build it for use in a Baja. So far I have rebuilt stock rods, stock bus heads with smaller valves that may need some work, AA piston & cylinders, 36 Dellortos & DTM conversion shroud. I have read several posts by owners who regretted not installing a performance cam upon rebuild. My question is: Will this engine benefit from a performance cam with the existing heads & carb setup? Would enlarging the valves help and what would costs be to perform headwork?

I had originally intended to build a stock lower end but I also don't want to hang out at the bottom of the dunes due to lack of power!

Thanks for your suggestions.

[craigvwdude]

ANY stock type 4 will benifit from a cam change. The stock cam is nasty..
The type 4 will make a good off road motor!

[GARRICK.CLARK]

Hi there.i'm doing a 1911cc build and am going with the web 86a cam.Not as good as jakes cams but not far off.If you need to spend some dollar on ya heads put some 42x36mm valves in.

[craigvwdude]

Just to let you know, Jakes cams are Web's. He just has them ground a little different.
Also EMW and CB make some good type 4 cams.
Good luck on your build!

[fasty67]

Sound like there is a few 1911cc Builds going on right now... Including mine. I'm a little suprised you spent the money on the DTM cooling for a Baja . You will always benefit from bigger/better cams and larger valves assuming you don't over/under do one or the other. Sounds like you knew that though. If you are going to put good money in the heads do the valve upgrades by a type 4 pro here. Then match your cam to your intended driving style and your head work....

[evernon]

Thanks for the replys,

I bought the DTM kit as I didn't like the stock fan shroud hanging way out back. Maybe it is cosmetic but it must shift weight a little forward of the stock setup. I also plan to pull air from the oil cooler to help get some heat in the interior. I am not sure how effective this will be but maybe coupled with heated seat covers it might buy me a few extra months of fall / winter use.

I am trying to put together a combination for the 1911 that will work for my application. The engine will see wide open, full throttle use in the dunes (St. Anthonies @ 5,000' elev.) but will also be a commuter around town 3,200' - 4,000'. I don't anticipate extended highway trips as we typically take the camper with a trailer for toys. I intend to have my 2ltr heads gone over & maybe have 42 x 36mm valves installed. The guys at Rimco said that the stock valves would run OK with a mild cam - probably be very torquey & good MPG. I have stock exhaust stubs I intend to fabricate a merged header, maybe buying a Tri-Mil later on. Carbs will be Dellorto 36's which I have been told should work well with this engine.

I have never had to design an engine for intended use, only used what I had or could afford on a limited budget. This time around though I would like to build something that I won't regret and am willing to get larger valves if it means the difference between having somewhat of a top end or not. My engine building experience is limited to top end replacement, maintenance etc. so this will be my 1st total rebuild.

What charactoristics should I be looking for in a cam for off road use? After reading through the cam selection at RAT, it appears that I have a few options but there is no mention of off-road use. The 9130 sounds like it would work and would allow higher rpm's than the 9550 or 9530. I am not sure that high revs are mandatory though as I rarely exceed 5000rpm in my rail (I may be subconciously terrified that the thing will blow up after 20 years of abuse). The 9550 sounds like it produces great low to mid range torque but it also says not to operate it continuously above 4,000 feet. The 9530 boasts a flat torque curve but says that it promotes great drivability. I like the idea of buying a kit (cam + all required valvetrain related upgrades) and Jake's prices seem compeditive though I am open to all options.

I have read a lot of posts from people building 1911s but very few from people who have found a combination of parts that work really well together & are happy to pass on the the winning combination.

Thanks

[evernon]

Has anyone utilized Jake,s 9530? I am leaning tords this kit but only because it sounds like it might work from the description on his web page. You have to pay a consulting fee to question the man concerning the product he sells.

It is frustrating that after days of searching forums I have not found postings from owner/builders with similar builds passing on the outcome.

[jim.fernish]

Has anyone utilized Jake,s 9530? You have to pay a consulting fee to question the man concerning the product he sells..

I believe Jake will help you select the proper cam, after you purchase has complete cam kit. Shoot him an email and ask, I read his forums and it's my option that he will give advise to the folks that buy his products. I could be wrong but I would ask.

[supaninja]

I got the 9530 in my street car and it is a nice flat tq curve that is very drivable. I bought the cam and lifters new from someone who ended up getting out of the VW scene and pieced together my own cam kit just like Jake's. I don't see why it wouldn't be great in a offroad vehicle, my redline is 6000 and rarely need to rev past 5000 on the street.

[evernon]

Hi all,

The guy that is going to re-do my heads suggested that the webcam 73 should work nicely for my application. He also is going to assemble the short block for me for a very reasonable price so things are proceeding! I now have to figure out what compression ratio I should have the heads set up to run. My builder suggested 8:1 to 9:1 but he sounded a little worried about overheating at the higher number. Remember that this engine will be primarily run at 3200' to 5000' but I may make the occasional trip to coastal dunes or desert at lower elevation.

If we set this up a 9:1, will it melt or explode if it is run at sea level?

[dstar5000]

9 sounds good, even if you go a couple thou over, don't sweat it.

[evernon]

Do I need to worry about valves contacting pistons? I have seen some flat top pistons that have a pocket for valve clearance. The AA's I have are completely flat on top. With a more aggresive cam than stock (web 73) do the valves open further than the face of the combustion chamber?

[Piledriver]

With a Web73 it should not be a concern, but it's easy to test when mocking up the engine.
You should test it anyway.

With long duration/high lift cams etc things start to interfere.

A web73 isn't one of those.

Expect to run premium and have to adjust your timing down some at sea level.
You will likely need a touch more than stock at altitude.

[evernon]

Got the heads & short block! I cant belive after sitting in a pile in my garage for years, this thing will hopefully roar to life soon. I started looking at the the jets in my Dells & according to the reccomendations in the Super Performance book, I think the Jets I have are too small. For a 1911 that should rev to 6000rpm, the worksheet says I should have:

36 venturi, 144 main, 180 main air correction & 60 idle jet

My carbs have:

30 venturi, 122 main, 180 main air correction & 55 idle jet

The book says to increase the air correction jet by two sizes for operation @ 7000'. Should I increase by one size for 3000' - 5000'?

Also, after reading posts at the 914 forum, the consensus was that smaller sized venturies than the recomended 36mm size work well with smaller displacement TIVs. I don't know how large of venturi I can fit in a 36 DRLA. New valve sizes are 36 & 42mm. I hope CB still sells this stuff!

All good advice appreciated!

[Clatter]

You got 42 x 36 valves and a Web 73 at 9:1 CR?

Be ready to have some fun.
That sounds like a really good combo for what you want to do.

Be sure to post your ongoing results.
Don't deny the next guy who wants to build a 1911 for his rail!

Dell 36s have a 36 vent by leaving the vent out.
You might get some 34s to help make them behave better down low.

The Superformance book specs are known to be pretty rich.
Only your tuning will tell you what your motor really wants.
I would be inclined to try those idles you already have, too.
Maybe just buy some mains, and see what you get?
It might give you an idea where you need to go...