The small "big block" project - The 1947 - Present Chevrolet & GMC Truck Message Board Network

NONHOG · 08-13-2010, 11:43 PM

So a trip to HF for some jackstands turned into an impulse buy on a 6.5 HP
"Greyhound" engine to replace the 2.8 HP factory "Doodlebug" engine.
After getting the new engine I have found on the internet that its a pretty popular swap.
I'm all for upgrades but this is fun because its my 13 yo sons minibike so he is on board this project (pushing and shoving)

NONHOG · 08-14-2010, 09:37 PM

Picked up the clutch today local $48 was $32 online plus $20 shipping.
Probably could have shopped around but happy its on now !
Still need to shorten the chain and figure out why it seems to idle so high ?
No test rides yet, sure sound powerful !

NONHOG · 08-14-2010, 09:38 PM

YouTube- 6.5 horse doodle bug

try this again.(going to need an easier kill switch !)

JohnC · 08-15-2010, 02:52 PM

Cool! Looks like a lot of fun!

**FRENCHBLUE72** · 08-23-2010, 10:03 AM

Sounds like she will be fast cant wait to see it go..

68C15 · 08-25-2010, 06:32 AM

I hope he is a safer driver than his Dad. LOL

nuke1 · 08-25-2010, 11:36 AM

Awesome!!!

NONHOG · 08-25-2010, 11:54 AM

Quote:

Originally Posted by JohnC

Cool! Looks like a lot of fun!

It has been so far, can't wait to have it working right.

Quote:

Originally Posted by FRENCHBLUE72

Sounds like she will be fast cant wait to see it go..

search youtube there are a# of people doing this swap.

Quote:

Originally Posted by 68C15

I hope he is a safer driver than his Dad. LOL

He already has a healthy respect for it. (see how long that lasts)

Quote:

Originally Posted by nuke1

Awesome!!!

Thanks !

Project has been on hold due to family issues. But we'll be back at it soon.
with updates(and vids I hope) !

884x4Sub · 08-26-2010, 06:15 PM

thats cool......!

NONHOG · 11-20-2010, 07:52 PM

Day 90 of the 90 day warranty I gave up on getting the Greyhound to run right. was a good call.
Today we installed greyhound #2 and it works great.
Too bad its 41 degree's out or we would still be riding it.
The things got some grunt!

red69ss · 11-20-2010, 11:29 PM

that looks cool!... looks like he's going to need a longer foot peg on the right side.

**Dieselwrencher** · 11-21-2010, 01:08 AM

Very cool! I was wondering how those greyhound engines really are.

NONHOG · 12-16-2013, 12:38 AM

Quote:

Originally Posted by red69ss

that looks cool!... looks like he's going to need a longer foot peg on the right side.

Thanks! must have missed this post. Yep always a work in progress. See story below.

Quote:

Originally Posted by Dieselwrencher

Very cool! I was wondering how those greyhound engines really are.

Thanks! Funny we had loads of fun with it then it sat just a bit and the fuel did the carb in. Tried pulling it apart a few times. Gave in and bought a new carb.
Just installed it today. Even though Jr. is driving now he still loves the silly little Doddlebug. So after I almost crashed it testing the new carb. Throttle was a bit sticky. We both rode it and enjoyed the few moments we had with it before I broke it.

We decided to make a header for it and tacked it up and needed to hear it before completing the welds. (of course!) It sounded pretty cool but while warming it up the chain which was a bit loose jumped off the sprockets and took out the tensioner. Dad was a hero for a short while.

I put a similar sized pipe within the "bad boy" pipe. Pics should tell the story.

NONHOG · 12-16-2013, 12:43 AM

I have a video but have to figure how to post it?
Getting low on gas but will try and finish welding the pipe up soon. Might add a baffle to quiet it down a tad?

NONHOG · 12-16-2013, 01:52 AM

Here we go....... https://www.youtube.com/watch?v=cHhbvWYF54U

alsriv2 · 12-16-2013, 12:41 PM

Very cool project. I had a bike like that many, many, many years ago. Did a huge upgrade from a 2.5hp Briggs to a 4hp Briggs. That thing would fly, but we had a hard time getting any parts up in Maine back then to keep it going.

68C15 · 12-18-2013, 07:38 PM

I had a similar bike in my early teens. It was a blast until I poured in some methanol. Cruising down the sidewalk I cracked the throttle. The cylinder head blew off and imprinted the seat base with bolt heads. That's what I get for shaving the head, relieving the valves, grinding the cam, and having a machinist weld the piston into a dome shape.

NONHOG · 12-22-2013, 11:07 PM

Quote:

Originally Posted by alsriv2

Very cool project. I had a bike like that many, many, many years ago. Did a huge upgrade from a 2.5hp Briggs to a 4hp Briggs. That thing would fly, but we had a hard time getting any parts up in Maine back then to keep it going.

Thanks! Its a knock off, but its a lot of fun. Funny how much speed parts are available for these HF 6.5 engines. Hope a tensioner is easy to find.

Quote:

Originally Posted by 68C15

I had a similar bike in my early teens. It was a blast until I poured in some methanol. Cruising down the sidewalk I cracked the throttle. The cylinder head blew off and imprinted the seat base with bolt heads. That's what I get for shaving the head, relieving the valves, grinding the cam, and having a machinist weld the piston into a dome shape.

I read that removing the governor takes the rpm from 3500 to 5000 (ish)
Its also has a good probability of blowing up.

For now it stays stock except air cleaner and header. Air cleaner yet to be figured out. K&N valve cover breather?

More progress on header till I ran out of gas. (MIG)

NONHOG · 12-22-2013, 11:11 PM

On the previous post, I nailed it on centering the pilot drill hole.

that never happens for me! Then used the step bit to get it the right size. Did some tacks to seal it up and hoping the offset hole will quiet it down a tiny bit?

08-13-2010, 11:43 PM	#1
NONHOG Registered User Join Date: Feb 2007 Location: Marana, Arizona Posts: 3,416	The small "big block" project So a trip to HF for some jackstands turned into an impulse buy on a 6.5 HP "Greyhound" engine to replace the 2.8 HP factory "Doodlebug" engine. After getting the new engine I have found on the internet that its a pretty popular swap. I'm all for upgrades but this is fun because its my 13 yo sons minibike so he is on board this project (pushing and shoving) Attached Images __________________ "I feel the need for speed!"... as soon as I am done with my nap.

08-15-2010, 02:52 PM	#4
JohnC Registered User Join Date: Feb 2009 Location: Oklahoma Posts: 7,461	Re: The small "big block" project Cool! Looks like a lot of fun!

08-23-2010, 10:03 AM	#5
FRENCHBLUE72 PROJECT 7DEUCE Join Date: Dec 2002 Location: GRANTS PASS OR Posts: 21,590	Re: The small "big block" project Sounds like she will be fast cant wait to see it go.. __________________ GO BIG GREEN GO DUCKS MEMBER #6377 72 k-5 daily driver 6'' lift 35'' 350-350-205 slowly getting rust free. Project "7DEUCE" check out my build http://67-72chevytrucks.com/vboard/s...d.php?t=267665 Tim Powell..R.I.P EastSideLowlife..... R.I.P..

08-25-2010, 06:32 AM	#6
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	Re: The small "big block" project I hope he is a safer driver than his Dad. LOL

08-25-2010, 11:36 AM	#7
nuke1 Registered User Join Date: Jun 2007 Location: Saskatoon, Saskatchewan,: Posts: 2,901	Re: The small "big block" project Awesome!!! __________________ James 1968 GMC "HAVOC" 1986 GMC "Frank" J.J.R.H. Design & Consulting My 68`Rebuild "HAVOC": http://67-72chevytrucks.com/vboard/s...d.php?t=316300 A 58' chev build thread: http://www.67-72chevytrucks.com/vboa...d.php?t=311238 1969 Camaro Pro Touring http://67-72chevytrucks.com/vboard/s...61#post3513361 Swiss Cheese: http://67-72chevytrucks.com/vboard/s...d.php?t=384390 Adjustable Trailing Arm How-To: http://67-72chevytrucks.com/vboard/s...d.php?t=321100 1968 Ford Farm Truck: http://67-72chevytrucks.com/vboard/s...=1#post6555587

08-14-2010, 09:37 PM	#2
NONHOG Registered User Join Date: Feb 2007 Location: Marana, Arizona Posts: 3,416	Re: The small "big block" project Picked up the clutch today local $48 was $32 online plus $20 shipping. Probably could have shopped around but happy its on now ! Still need to shorten the chain and figure out why it seems to idle so high ? No test rides yet, sure sound powerful ! Attached Images __________________ "I feel the need for speed!"... as soon as I am done with my nap.

08-26-2010, 06:15 PM	#9
884x4Sub p p pullin' Join Date: Apr 2008 Location: oshawa ontario Posts: 373	Re: The small "big block" project thats cool......! __________________ doug

11-20-2010, 07:52 PM	#10
NONHOG Registered User Join Date: Feb 2007 Location: Marana, Arizona Posts: 3,416	Re: The small "big block" project Day 90 of the 90 day warranty I gave up on getting the Greyhound to run right. was a good call. Today we installed greyhound #2 and it works great. Too bad its 41 degree's out or we would still be riding it. The things got some grunt! Attached Images __________________ "I feel the need for speed!"... as soon as I am done with my nap. Last edited by NONHOG; 11-20-2010 at 08:13 PM.

11-20-2010, 11:29 PM	#11
red69ss Burnouts are therapeutic Join Date: Jun 2007 Location: lancaster, south carolina Posts: 851	Re: The small "big block" project that looks cool!... looks like he's going to need a longer foot peg on the right side. __________________ 1969 CHEVELLE SS 1972 C10 ALMOST DAILY DRIVER 1968 C10 RUSTBUCKET (MISSION IMPOSSIBLE) 1972 PONTIAC LEMANS CONVERTIBLE (WIFE'S CAR) "My wife and I were happy for twenty years. Then we met." - Rodney Dangerfield "The difference between genius and stupidity is that genius has its limits." - Einstein

11-21-2010, 01:08 AM	#12
Dieselwrencher 6>8 Plugless........ Join Date: Sep 2007 Location: Prairie City, Ia Posts: 17,138	Re: The small "big block" project Very cool! I was wondering how those greyhound engines really are. __________________ Ryan 1972 Chevy Longhorn K30 Cheyenne Super, 359 Inline 6 cylinder, Auto Trans, Tilt, Diesel Tach/Vach, Buckets, Rare Rear 4-link and air ride option Build Thread 1972 GMC Sierra Grande Longhorn 4x4 1972 Chevy Cheyenne Super K20 Long Step side tilt, tach, tow hooks, AC, 350 4 speed 1972 C10 Suburban Custom Deluxe 1969 Chevy milk truck 1971 Camaro RS 5.3 BTR STG3 Cam Super T10 1940 Ford 354 Hemi 46RH Ford 9" on air ride huge project *Tired of spark plugs? Check this out.*

12-16-2013, 12:43 AM	#14
NONHOG Registered User Join Date: Feb 2007 Location: Marana, Arizona Posts: 3,416	Re: The small "big block" project I have a video but have to figure how to post it? Getting low on gas but will try and finish welding the pipe up soon. Might add a baffle to quiet it down a tad? Attached Images __________________ "I feel the need for speed!"... as soon as I am done with my nap.

12-16-2013, 01:52 AM	#15
NONHOG Registered User Join Date: Feb 2007 Location: Marana, Arizona Posts: 3,416	Re: The small "big block" project Here we go....... https://www.youtube.com/watch?v=cHhbvWYF54U __________________ "I feel the need for speed!"... as soon as I am done with my nap.

12-16-2013, 12:41 PM	#16
alsriv2 Registered User Join Date: Sep 2010 Location: Formerly MD and San Diego, now loving life in Arizona Posts: 1,636	Re: The small "big block" project Very cool project. I had a bike like that many, many, many years ago. Did a huge upgrade from a 2.5hp Briggs to a 4hp Briggs. That thing would fly, but we had a hard time getting any parts up in Maine back then to keep it going. __________________ Alan 2012 Ram 3500 Dually Crew Cab 6.7 Cummins 2014 Palomino Columbus 340RK 5th wheel '69 Chevy C10 396BB

12-18-2013, 07:38 PM	#17
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	Re: The small "big block" project I had a similar bike in my early teens. It was a blast until I poured in some methanol. Cruising down the sidewalk I cracked the throttle. The cylinder head blew off and imprinted the seat base with bolt heads. That's what I get for shaving the head, relieving the valves, grinding the cam, and having a machinist weld the piston into a dome shape. __________________ Man rule #77...if you own a 67 stepside with a caddy 472 you will never be in danger of loosing you man card

12-22-2013, 11:11 PM	#19
NONHOG Registered User Join Date: Feb 2007 Location: Marana, Arizona Posts: 3,416	Re: The small "big block" project On the previous post, I nailed it on centering the pilot drill hole. that never happens for me! Then used the step bit to get it the right size. Did some tacks to seal it up and hoping the offset hole will quiet it down a tiny bit? Attached Images __________________ "I feel the need for speed!"... as soon as I am done with my nap.



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