Flathead Briggs Race engine

[RustyRedneck]

Hey fellas, I'm working on a couple 5 hp flathead Briggs engines for my race kart. I've never raced these things before and I'm working on a shoe string budget. One of them is missing a head bolt but supposedly ran in the last couple years. I'm wondering what type if bolt I should get replace it. Would it be beneficial to get a grade 8 or should I stick with a grade 5 so the bolt can take more stretch. Also, I would like to pull the side covers and heads on both of them and just check out what secrets they hold. Will stock gaskets do for a racing application? Thanks in advance!

 

[65ShelbyClone]

The head fasteners are 5/16-18 flange bolts. I don't think grade 8 is of any benefit for them. Stock gaskets would be fine IMO.

 

[zbuck]

Grade 5's are fine. If those are stock engines you are barking up the wrong tree to run them on a race kart. As they are only 3600 rpm engine with a sheet metal oil slinger. They will be grenade engines with out some modifications.

 

[JTSpeedDemon]

Yeah, might do better with Predator 212s or something maybe more modern. I've got a 1985 5 HP flathead. How old are said engines?

 

[RustyRedneck]

Both engines have been run on racing karts before but it's been a few years for each. I would say these engines came out of the factory in the '80s but I haven't run numbers yet.

 

[JTSpeedDemon]

Serial number and other numbers are stamped on the blower housing near the carb. Here's a link to the B&S designation system:http://www.briggsandstratton.com/~/media/Files/BriggsandStratton/Engine%20Model%20Key%20Rev2-11.pdf. For serial number, first two digits are year, next two are month, next two are day, last two are mfg, plant and line(don't know what it means, but mine says 07). Got any pics of engines?