engine issues

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Gene-C
Posts: 2949
Joined: Fri Feb 12, 2010 6:00 am

engine issues

Post by Gene-C »

I have a 2275. or so i was told. I had it checked out and it is all high end products. But is seams like it just is not as powerful as i would think. It really gets up in 1 st 2 nd and 3rd but 4 th is ok top's out at about3500 rpm. Now it is a street pro trans and i am running 31'' tires and the gears are stock size. I have duel 44 idf's with 135 main jets and the plugs look good . does anyone have the same set up + or - I have to shift at a high rpm or it will bog down I was told i could lower the carbs to 40 idf's and this would give me more lower tork. at a loss for higher end. I am thinking of a turbo. but it may be better for a trans change with close 3 and 4. I would like to hear what you have to say as far as what you may have done. There is enough power for street but I would like to take it on the sand and have the ability to get out of 2nd
newmanx59
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Joined: Mon Mar 14, 2005 9:00 pm

Post by newmanx59 »

Do you have any other specs on the engine...IE: What cam, what heads, valve sizes, what size venturies you are running in the carbs, carb jetting, Ring and pinion ratio, and compression ratio? That engine should have all the power you need at low RPM and high RPM. The main jets seem awful small. Here is the jetting I'm running in my dual Webered 1914. Idle: 50 Emulsion tubes: F-11 Air correction: 200 Main gas: 150 Venturies: 36mm Granted, jetting all depends on the engine specs..but your jetting seems to be off.
Gene-C
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Joined: Fri Feb 12, 2010 6:00 am

Post by Gene-C »

also a turbo wouldn't help with the low end at all. Just because turbo's have to wind up and kink in at a higher rpm about 2000 RPM or so for most but it depends on the size of the turbo. I would suggest doing a compression test and seeing if your motor needs to be rebuilt. As well as going through and doing a complete tuning. Adjust the timing, valves, make sure all you plugs are good, fine tune the carbs, you know the basics.:laugh1:
Gene-C
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Joined: Fri Feb 12, 2010 6:00 am

Post by Gene-C »

Exhaust restricted maybe? My 1600 tops out at about 70 mph in 4th gear with 29" tires. I have the later higher geared (single side cover) tranny. It tops out about 70 in third also. It feels like I'm pulling a parachute. I would think a 2275 should overcome those issues. Personally I would stick with the 44 IDFs, I believe your problem lies elswhere. My :2cents: and that's what it may be worth. :hello:
Lee
Posts: 246
Joined: Tue Mar 15, 2005 9:00 pm

Post by Lee »

If you have stock gears for a later Bug transmission ('67 through '72), you most likely have the following: First = 3.8 Second = 2.06 Third = 1.26 Fourth = 0.89 Ring and Pinion = 4.125 The gears for the '73 and later Bug transmissions are a bit different: First = 3.78 Second = 2.06 Third = 1.26 Fourth = 0.93 Ring and Pinion = 3.875 According to the formula I have, if you run 31" tires on a transmission made between '67 and '72, you are taching 3,000 RPM at 75.4 MPH in fourth gear. You would be doing 59.6 MPH at that RPM with stock tires. At 3,500 RPM you should be running along at about 88 MPH. Keep in mind these numbers will vary, as the actual measured tire diameter is always different than the listed diameter. If your engine redlines at 5,000 RPM, you should be able to get to 125.7 MPH with your current setup, provided the engine has enough power. I would say that a lower fourth gear is in order, perhaps also a lower third gear if you wish to use it in the sand. Trying to pump more and more power out of the engine is only solving the problem from one end. Increasing the output of the engine while continuing to spin it at the lower RPMs also increases heat production without increasing the engine's ability to cool itself. VW engines like to live up higher in the RPM scale than V8 engines, both in respect to power and in cooling. Keep the engine within its power band, and it will be much happier. There really is a science to all this.
joemama
Posts: 119
Joined: Mon Mar 14, 2005 9:00 pm

Post by joemama »

Just some related thoughts. I would think that topping out at 3500rpm in 4th would be somewhat expected, what with the overdrive 4th gear, and the aerodynamics of a buggy. My buggy has a 1914, mild cam, single Zenith 32 2 barrel carb, 009. When in the sand, there is no problem cruising along in 3rd gear in the flats, other than the suspension can limit speed more so than the power of the engine. While duning, it is mainly 2nd gear, downshifting to 1st to crest over very steep dunes. I run 31" tires, prostreet trans like yours. Again, the thing that mostly limits my buggy on the sand is the suspension.
Gene-C
Posts: 2949
Joined: Fri Feb 12, 2010 6:00 am

Post by Gene-C »

thank you . the engine is a fairly new engine and it does run strong. i was just thinking it should have more power in 4th.. and the turbo would be for the higher end and maybe enough to push it in the sand in 3rd..?? it has just been tuned up . It seam's to be more likely than not the tire size and the gear size combo.. any one want to buy a new swing pro street trans? less than 100 miles on it... I think I need to get the close 3 and 4 th gear.. maybe even add a 5th for good measure.?? still a turbo sounds good with fuel injection. 3200.$
BuggyBob
Posts: 460
Joined: Sun Feb 14, 2010 6:00 am

Post by BuggyBob »

i thunk you might have been told wrong. to be sure, you will have to tear the motor down and look whats really inside
Gene-C
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Joined: Fri Feb 12, 2010 6:00 am

Post by Gene-C »

Well there is no reason to tear it down . it runs great. and has strong compression per the mechanic who tuned it up. he said it is a strong enging, the question that i cant prove is the size of the motor....
Gene-C
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Joined: Fri Feb 12, 2010 6:00 am

Post by Gene-C »

I had 140 main jets but it was running rich with a lot of soot. after putting a 135 in it ran good and the plugs look brown and not black. OK i just got my speedo calibrated. it will go about 75 to 80 . this seams slow. but it will hit 60mph in about 9 sec all gears jump to 5000rpm with no problem but 4th is 3000 to 3500 this is with no one in front of me. there were higher speeds o the freeway when others were sucking me in the back draft. [QUOTE=newmanx59]Do you have any other specs on the engine...IE: What cam, what heads, valve sizes, what size venturies you are running in the carbs, carb jetting, Ring and pinion ratio, and compression ratio? That engine should have all the power you need at low RPM and high RPM. The main jets seem awful small. Here is the jetting I'm running in my dual Webered 1914. Idle: 50 Emulsion tubes: F-11 Air correction: 200 Main gas: 150 Venturies: 36mm Granted, jetting all depends on the engine specs..but your jetting seems to be off.[/QUOTE]
Jim Ishmael
Posts: 11
Joined: Fri Aug 19, 2005 8:00 pm

the question that i cant prove is the size of the motor....

Post by Jim Ishmael »

"the question that i cant prove is the size of the motor...." Seems I recall in the old days we hooked up a manometer to a cylinder and turned the engine over to get one cylinders capacity then multiplied by the number of cylinders. unless it was a cheater at the drag races the cylinders are all the same cc's.
Gene-C
Posts: 2949
Joined: Fri Feb 12, 2010 6:00 am

Post by Gene-C »

you could always pour water in and see how meany cc's go into a cylender!:crazy:
newmanx59
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Joined: Mon Mar 14, 2005 9:00 pm

Post by newmanx59 »

The main jets only affect the mixture over 4000 rpm. Can you post what size jets you are using in the carbs?
Gene-C
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Joined: Fri Feb 12, 2010 6:00 am

Post by Gene-C »

the only jet size i know is the mail it is 135. it was 140 but i was blowing soot and fouling the plugs. on the other hand it was running crappy in the low end and better in the high end then sort of.. the carbs i have 44idf were used and were not on this engine how do i tell the size of jets i have? does anyone have a combo of jets they think i should get? I am only at 900ft about sea level. Maybe i need to buy a book too
Reverb
Posts: 203
Joined: Fri Mar 18, 2005 10:00 pm

Post by Reverb »

Are you using a stock, or a lightened flywheel?
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