Heymow - Lawnmower Racing Forum

Engine Help => Briggs Flathead => Topic started by: darksider61 on February 25, 2014, 03:05:28 pm

Title: 11 HP Flathead 25 CI or 14 HP OHV 28 CI
Post by: darksider61 on February 25, 2014, 03:05:28 pm: The class I'm building for at a local track allows a stock motor and a 31 CI limit.I have an 11 HP Flathead and a 14 HP OHV and just wondering if anyone could give me any advise which motor would be the best to use.I have also read brief topics on mixing parts between the two as some parts are better in each motor.Just looking for the best of both worlds want what will make power and hold up
Title: Re: 11 HP Flathead 25 CI or 14 HP OHV 28 CI
Post by: Tazz914 on February 25, 2014, 03:39:25 pm: The ohv will give you more tourqe and have more power but the flathead will hold up better
Title: Re: 11 HP Flathead 25 CI or 14 HP OHV 28 CI
Post by: BIG AL 202 on February 26, 2014, 09:11:12 am: THERE IS NO SUBSTITUTE FOR CUBIC INCHES. THE 11hp WHICH IS 25 ci IS NOT A GOOD ONE FOR RACING. ONLY THE HEAD AND COIL ARE WORTH KEEPING. GO WITH THE OHV.
Title: Re: 11 HP Flathead 25 CI or 14 HP OHV 28 CI
Post by: royalblu68f100 on February 26, 2014, 10:56:40 am: Is this an AVS OHV or a non-AVS (AVS uses a plastic flywheel shroud, non-AVS uses steel)? The non-AVS has a little more sturdy counter weight system attached to the crankshaft. On the local level we have used stock motors up to 4000-4500 RPMs and used them for many races.
Title: Re: 11 HP Flathead 25 CI or 14 HP OHV 28 CI
Post by: BIG AL 202 on February 26, 2014, 12:42:40 pm: AVS IS STILL BETTER THEN THE 11hp FOR POWER, TORQUE, AND RELIABILITY.
Title: Re: 11 HP Flathead 25 CI or 14 HP OHV 28 CI
Post by: Troybilt Pony on February 26, 2014, 07:56:29 pm: Not reliablity ^^ I've dumped kerosene in my work tractor on accident before and she ran like a top.. well.. not a top but she ran. She fires up every time.
Title: Re: 11 HP Flathead 25 CI or 14 HP OHV 28 CI
Post by: willenglish on February 26, 2014, 08:39:37 pm: I'd get rid of those counterweights....they are obscenely heavy and they are all troublesome. The brass counterweight setup works great and really simplifys the engine.
Title: Re: 11 HP Flathead 25 CI or 14 HP OHV 28 CI
Post by: darksider61 on March 01, 2014, 09:06:14 pm: Ok I'm really new to the Lawn Mower engines and keep reading people saying to get rid of the counter weights and use the brass counter weights.The problem is I have no idea what they are talking about,is there somewhere I can get the info on how to do this?I work on cars and have a good supply of tools and if I don't have it I will get it I just need to know what to get.
Title: Re: 11 HP Flathead 25 CI or 14 HP OHV 28 CI
Post by: birdman_express on March 01, 2014, 10:06:19 pm: Do a search for ARC brass weights.
Title: Re: 11 HP Flathead 25 CI or 14 HP OHV 28 CI
Post by: crazycraftsman on March 01, 2014, 10:16:01 pm: So does the ohv motor have a plastic or metal shroud over top of engine??? If it's metal and like you said has to be stock I would just get a billet dog bone. Ec / arc sells them. 25 bucks. This should work good for you if your motor inside is in good shape . If it's plastic ,if your rules allow get the crank balanced.

Owen