Difference between a 2.0L out of a bus or 914 |
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Difference between a 2.0L out of a bus or 914 |
carnitasboy |
Feb 10 2011, 09:42 AM
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#1
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Newbie Group: Members Posts: 2 Joined: 8-March 10 From: San Diego Member No.: 11,444 Region Association: Southwest Region |
Is there a difference in a 2.0L out of a bus as opposed to a 2.0L out of a 914? I was under the assumption that a bus engine had different heads. I don't know where I heard that. Maybe I just made that up.
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hot_shoe914 |
Feb 10 2011, 09:46 AM
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#2
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on ramp passer Group: Members Posts: 3,802 Joined: 20-November 07 From: Earle, Ar. Member No.: 8,354 Region Association: None |
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Root_Werks |
Feb 10 2011, 09:56 AM
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#3
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Village Idiot Group: Members Posts: 8,338 Joined: 25-May 04 From: About 5NM from Canada Member No.: 2,105 Region Association: Pacific Northwest |
There are a number of differences between the two. Just a few I know of (Depends on the year of the bus vs 914):
Bus: 4 bolt intake heads with smaller valves No windage tray Different cam Used L-Jet for I think all versions 78-79 came in a carb'd version that had a mechanical fuel pump Bus engines are lower reving torque monsters compared to 914 2.0s There are tons more differences I'm sure. That's what's off the top of my little head. |
Cap'n Krusty |
Feb 10 2011, 10:01 AM
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#4
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Cap'n Krusty Group: Members Posts: 10,794 Joined: 24-June 04 From: Santa Maria, CA Member No.: 2,246 Region Association: Central California |
There are a number of differences between the two. Just a few I know of (Depends on the year of the bus vs 914): Bus: 4 bolt intake heads with smaller valves No windage tray Different cam Used L-Jet for I think all versions 78-79 came in a carb'd version that had a mechanical fuel pump Bus engines are lower reving torque monsters compared to 914 2.0s There are tons more differences I'm sure. That's what's off the top of my little head. Many of the few differences you 'know" are wrong. The carbed versions were 1972-1974, all the others had L-jet. The cam was the same until 1977, AFIK, when they changed to hydraulic lifters. They'll rev the same as 2.0 914 engines, but the power is somewhat reduced by the head design, the hydraulic cam, and the L-jet EFI. The Cap'n |
SirAndy |
Feb 10 2011, 12:11 PM
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#5
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Resident German Group: Admin Posts: 41,688 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
Doesn't the bus engine also have lower compression? I recall seeing deep dished bus pistons before ...
(IMG:style_emoticons/default/idea.gif) |
orange914 |
Feb 10 2011, 12:32 PM
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#6
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http://5starmediaworks.com/index.html Group: Members Posts: 3,371 Joined: 26-March 05 From: Ceres, California Member No.: 3,818 Region Association: Northern California |
Doesn't the bus engine also have lower compression? I recall seeing deep dished bus pistons before ... (IMG:style_emoticons/default/idea.gif) yes |
Root_Werks |
Feb 10 2011, 01:00 PM
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#7
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Village Idiot Group: Members Posts: 8,338 Joined: 25-May 04 From: About 5NM from Canada Member No.: 2,105 Region Association: Pacific Northwest |
There are a number of differences between the two. Just a few I know of (Depends on the year of the bus vs 914): Bus: 4 bolt intake heads with smaller valves No windage tray Different cam Used L-Jet for I think all versions 78-79 came in a carb'd version that had a mechanical fuel pump Bus engines are lower reving torque monsters compared to 914 2.0s There are tons more differences I'm sure. That's what's off the top of my little head. Many of the few differences you 'know" are wrong. The carbed versions were 1972-1974, all the others had L-jet. The cam was the same until 1977, AFIK, when they changed to hydraulic lifters. They'll rev the same as 2.0 914 engines, but the power is somewhat reduced by the head design, the hydraulic cam, and the L-jet EFI. The Cap'n Frig an egg, goes to show how much I DON'T know. (IMG:style_emoticons/default/rolleyes.gif) I have to remember to keep my mouth shut, some poor idiot might actually listen one of these days. |
Sleepin |
Feb 10 2011, 01:21 PM
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#8
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Advanced Member Group: Members Posts: 3,647 Joined: 20-November 07 From: Grand Junction, Co. Member No.: 8,357 Region Association: Rocky Mountains |
Bus pistons....yes in a 914. :disgust:
(IMG:http://www.914world.com/bbs2/uploads_offsite/i171.photobucket.com-8357-1297365711.1.jpg) |
carnitasboy |
Feb 10 2011, 01:22 PM
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#9
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Newbie Group: Members Posts: 2 Joined: 8-March 10 From: San Diego Member No.: 11,444 Region Association: Southwest Region |
So, has anyone put a bus engine in their 914? Is it good? Bad? Why would you want to?
The reason I ask is I have access to one. I would like to get 120+ HP and I wanted to know what kind of mods I would have to make to a bus 2.0L. Probably not worth it. |
VaccaRabite |
Feb 10 2011, 01:46 PM
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#10
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En Garde! Group: Admin Posts: 13,465 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region |
There is a "bus" engine in my 914.
At least, it was a bus engine at one point. It was built into a 120Hp 2056, probably similar to what you have in mind. There are a few differences from 914 cases. 1) the dipstick is different for a bus. I carefully pulled the dipstick tube out and put in a 914 tube. 2) no taco plate oil temp sender. I scavenged one off another engine I had. The location is there, but the taco plate on the bus is just flat, it does not have the sender mounting location on it. 3) you can not use the oil temp sender off the 914. There is a big hunk of case in the way. You CAN use the short modern VDO sender, but then HAVE to use the 2 1/16 inch VDO oil temp gauge, not the big one from the 914. Other option is to hog out the case for the 914 sender to clear. I did not go that route. 4) Bus engine cases tended to warp around the registers. Mine has to be surfaced in order for the cylinders to sit in the case and be flush. This can happen to all T4 cases, but bus cases are especially prone as they were pushing big assed buses instead of little sports cars. 5) there is an oil gallery at the front of a bus case that needs to be plugged. I forget what its for in a bus. mine had a simple block off plate made from scrap aluminum. I used the bus case as the journals were std. The 2.0 914 case I had was bored out and I was having a hard time finding bearings. Also, the oil galleries on my bus case had been tapped, and the 914 case still had freeze plugs. Zach |
type47 |
Feb 10 2011, 02:18 PM
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#11
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Viermeister Group: Members Posts: 4,254 Joined: 7-August 03 From: Vienna, VA Member No.: 994 Region Association: MidAtlantic Region |
5) there is an oil gallery at the front of a bus case that needs to be plugged. I forget what its for in a bus. mine had a simple block off plate made from scrap aluminum. If the oil galley is at the bottom of the case (cooling fan end of engine, opposite side from the oil cooler) then it's possibly for an oil fill. My Vanagon has an oil filler that is accessed by a door behind the license plate. That's where the dipstick is and the cap over the oil filler. |
Bleyseng |
Feb 10 2011, 02:22 PM
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#12
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Aircooled Baby! Group: Members Posts: 13,035 Joined: 27-December 02 From: Seattle, Washington (for now) Member No.: 24 Region Association: Pacific Northwest |
(IMG:style_emoticons/default/agree.gif) to what Zach says plus
Totally different flywheels Low CR 7.3 to one Tiny 37x33 valves in the heads 78 and later came with the crappy hydro lifters and cam usually the cases are warped and need work Heads are shot by 100k and drop valve seats, toss em With lots of work a bus case can work as the crank, rods are the same but you have to put that little sleeve in the end of the crank |
Cap'n Krusty |
Feb 10 2011, 03:39 PM
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#13
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Cap'n Krusty Group: Members Posts: 10,794 Joined: 24-June 04 From: Santa Maria, CA Member No.: 2,246 Region Association: Central California |
Bus crankshafts have the pilot bearing (same part as the one used in a 914) installed in the crank because the mainshaft is longer. Bus cranks for use with an auto trans don't have the bearing. 914s have the bearing in the flywheel. The bearing in the bus crank doesn't interfere with anything in the 914 application, so it can be left in place.
The Cap'n |
underthetire |
Feb 10 2011, 04:25 PM
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#14
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914 Guru Group: Members Posts: 5,062 Joined: 7-October 08 From: Brentwood Member No.: 9,623 Region Association: Northern California |
Since I am currently running a 2.0 bus engine...They work once modified to fit a 914 (dipstick). The hydro lifters do work, but will limit the extreme high RPM. They have torque, but fade quick over 4500. For a temporary engine, go for it. For a 100+ hp engine, forget about it. The heads would never work.
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Al Meredith |
Feb 10 2011, 07:47 PM
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#15
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Senior Member Group: Members Posts: 961 Joined: 4-November 04 From: Atlanta, ga Member No.: 3,061 |
In addition to the big dish in the piston ( lower compression) the connecting rods are more robust at the large end and weigh much more than a 914.
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Bleyseng |
Feb 11 2011, 03:32 AM
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#16
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Aircooled Baby! Group: Members Posts: 13,035 Joined: 27-December 02 From: Seattle, Washington (for now) Member No.: 24 Region Association: Pacific Northwest |
Bus crankshafts have the pilot bearing (same part as the one used in a 914) installed in the crank because the mainshaft is longer. Bus cranks for use with an auto trans don't have the bearing. 914s have the bearing in the flywheel. The bearing in the bus crank doesn't interfere with anything in the 914 application, so it can be left in place. The Cap'n True, but when I have had the cranks worked on they pull the bearing so "IF" you are going to use a crank without the bearing put a bearing in or that stop. Otherwise the bearing on your 914 flywheel will move around into the crank and the pilot shaft will flop around. Nah, the rods and crank are the same, even have a 039 part number as Porsche figured out how to built the 2.0L as VW thought you could only go to 1800 with a 66mm stroke. |
nathansnathan |
Feb 11 2011, 07:53 AM
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#17
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Senior Member Group: Members Posts: 1,052 Joined: 31-May 10 From: Laguna Beach, CA Member No.: 11,782 Region Association: None |
Another difference, the bus cases for the carb'd engines have a bronze sleeve that goes 'through' one of the oil galley holes by the flywheel end, for the mechanical fuel pump pushrod. When you plug those holes in the case, you have to leave that one alone as going through it will screw up your oil pressure.
Besides blocking up the pulley end flange for the oil fill, you have to block the flange for the fuel pump also. The finish on a bus case isn't as nice, also, like more casting marks, burrs, not as shiny. Some bus cases don't have the slots to put in a windage tray, even, but some do. The hardest part I would think would be making the hole for the tube to check the oil level, as bus cases don't have that steel tube coming out the top. |
HAM Inc |
Feb 11 2011, 08:50 AM
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#18
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Senior Member Group: Members Posts: 846 Joined: 24-July 06 From: Watkinsville,GA Member No.: 6,499 Region Association: None |
The 2.0 bus heads are worth scrap $ and nothing more. Only because they have been so heat soaked and used up pushing the big box around that the aluminum casting is fatiqued.
I quit working withused bus heads ~4 years ago. New (or even slightly used) AMC 2.0 bus heads can be worked into great heads for a 2056 (or a 2316 for that matter). The busses have a 15cc dish in the piston, but the 2.0 bus heads have ~49cc chambers compared to the ~58cc 2.0 914 heads which also have smaller dish pistons, ~7cc's in the U.S. IIRC |
Cap'n Krusty |
Feb 11 2011, 09:04 AM
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#19
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Cap'n Krusty Group: Members Posts: 10,794 Joined: 24-June 04 From: Santa Maria, CA Member No.: 2,246 Region Association: Central California |
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Cap'n Krusty |
Feb 11 2011, 09:10 AM
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#20
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Cap'n Krusty Group: Members Posts: 10,794 Joined: 24-June 04 From: Santa Maria, CA Member No.: 2,246 Region Association: Central California |
Bus crankshafts have the pilot bearing (same part as the one used in a 914) installed in the crank because the mainshaft is longer. Bus cranks for use with an auto trans don't have the bearing. 914s have the bearing in the flywheel. The bearing in the bus crank doesn't interfere with anything in the 914 application, so it can be left in place. The Cap'n True, but when I have had the cranks worked on they pull the bearing so "IF" you are going to use a crank without the bearing put a bearing in or that stop. Otherwise the bearing on your 914 flywheel will move around into the crank and the pilot shaft will flop around. Nah, the rods and crank are the same, even have a 039 part number as Porsche figured out how to built the 2.0L as VW thought you could only go to 1800 with a 66mm stroke. Do you guys just sit around making this shit up? The needle bearing is pressed into the flywheel. If it moves, there's something wrong with the flywheel. The Cap'n |
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