New engine build 2165 (with pics) - compression questions

srfndoc · Last edited by srfndoc on Fri Nov 11, 2011 12:13 pm; edited 1 time in total

Motor is almost finished now, here are the specs:

AS41 case - lifter bores sleeved (pic), full flowed
78 DPR crank
AA 94 P&C's
CB H-Beam 5.4" Rods
CB 044 42x37.5 Ported/Polished heads (see pics)
Web 109 cam
Scat Pro Comp 1.25 Forged Rockers (changing to 1:1 rockers)
Udo Lifters
HPMX 44's - Intakes port matched to heads
Everything balanced by Berg

Deck is .055 with 58cc chambers giving me 9:1 compression.

This is going in a 68 bus and will be a weekend driver only. Should I have gone with a lower compression ratio (I don't mind running premium) as I'm concerned about running hot in this configuration. What exhaust size would you recommend for this setup?

Image may have been reduced in size. Click image to view fullscreen.

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RPM=(MPH*336* (R&P*4th*1.26))/Tire Diameter in inches

mark tucker · Posted: Fri Nov 11, 2011 9:27 am Post subject:

I would bring the pistons .040 head clearance.and do a little chamber work if you want the cr a bit lower,or some piston profiling.9-9.5 cr should be fine,butI dont know the specs of that cam. with those ports in a bus I would not have more than .040 piston to head clearance. and throw away that split ring spacer,get a racer spacer.($10.00)and if you can have the bearings coated.

srfndoc · Posted: Fri Nov 11, 2011 9:55 am Post subject:

Here are the specs of the cam:

The split ring spacer was tossed.
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RPM=(MPH*336* (R&P*4th*1.26))/Tire Diameter in inches

ALB · Posted: Fri Nov 11, 2011 10:38 am Post subject:

Most cams designed for 1.1 rockers that can be used safely with 1.25's have approx a 40' spread between the advertised duration and @ 0.050" figures. The 109 has only 27', which leads me to believe it has fairly fast ramps. While this is a good thing (lifts the valve up quickly, establishing flow earlier and creating more torque), I would check with Webcam if it is safe to use with the 1.25's. If it is anything like Engle's VZ series cams, with 1.25's the ramps would so harsh no conventional spring could properly control them.
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srfndoc · Posted: Fri Nov 11, 2011 10:48 am Post subject:

Yeah, I checked with them previously and they said you can but it's right on the border. They said if I do to definitely run dual springs and I also had the lifter bores sleeved for added protection.
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RPM=(MPH*336* (R&P*4th*1.26))/Tire Diameter in inches

baked beetle · Posted: Fri Nov 11, 2011 11:26 am Post subject:

that is going to be an amazing engine for your bus and you will not regret the compression ratio........at all. Cool

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57' Theirs
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srfndoc · Posted: Fri Nov 11, 2011 12:07 pm Post subject:

Yeah, I'm pretty excited about it. After thinking thru the ratio rockers further I think I'm going to switch out to 1:1 rockers (solid shafts, german VW rockers and elephant feet adjusters) to keep things on the safe side.
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RPM=(MPH*336* (R&P*4th*1.26))/Tire Diameter in inches

jfats808 · Posted: Fri Nov 11, 2011 12:41 pm Post subject:

Bravo on running 94s for a bus engine. Nice cam choice too. Going to be a bad lil bitch. Post your experience with the ( what I assume your going with) forged version of the AA piston set. I have a 2165 complete engine kit on my shelves and would like to know if the AA forged 94s work well or not. The last 1776 i assembled with AA 90.5s I found 2 out of 4 cylinders were tighter in the register and needed some light coaxing to slip in. Nice build.
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baked beetle · Posted: Fri Nov 11, 2011 1:25 pm Post subject:

I would run the good quality scat rocker assemblys with those dual spring heads. the change doesn't make it any 'safer' imo. don't worry the valves won't hit the piston. Wink

_________________
These days people like me are hard to find- we don't give a damn what you think, about what we think. - JR
____________________
66' His
57' Theirs
63' Hers
62' Drag Bug - Theirs 13.1 @ 101 mph (GONE)

ALB · Posted: Fri Nov 11, 2011 1:30 pm Post subject:

srfndoc · Posted: Fri Nov 11, 2011 2:26 pm Post subject:

srfndoc · Posted: Thu Nov 08, 2012 12:09 pm Post subject:

1 year follow up post:

Motor has about 800 miles on it (yes, I don't drive much) and has been everything I thought it would be. Very happy with the setup.
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RPM=(MPH*336* (R&P*4th*1.26))/Tire Diameter in inches

mark tucker · Posted: Thu Nov 08, 2012 12:45 pm Post subject:

I would also bring the deck clearance up to .040, or 0 with a .040 copper head gadget.then if needed do some chamber work to lower it to between 9.0&9.5. use a 1.625 header(1 5/8") I think a 1.5" would be to small & the chambers run to hot.use a good free flowing muffler,no it dosent have to be loud. I should be a nice ride.

RailBoy · Posted: Thu Nov 08, 2012 12:53 pm Post subject:

Think the motor is already in Mark, good effort though,lol.... Wink

RB
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[quote="smitty24"]"HELP, I ported my own heads and now have fire coming out my ass" .[/quote]
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modok · Posted: Thu Nov 08, 2012 7:28 pm Post subject:

NICE!
What's the top speed now? Very Happy

KopfenJager · Samba Member Joined: December 09, 2011 Posts: 582

sweet!


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