7000rpm

If they are d dish, looks like this one http://www.precisionintl.com/Engine.aspx?ID=1730&EID=13086 oh and try source a rollmaster adjustable cam gear set. It pays to have the cam dialed in the right spot

The link i sent you has the pistons. Look at the first two listings. Shows STD , 20 thou oversize and 40 thou oversize

This is what my knife edged 4k crank looks like. Not sure if its the ideal thing for a regular road car though. I managed to get hold of an ACL brand kit of gumtree, as they went out of business a few years ago pistons and rings can be found here (and lots of other stuff...as ive just discovered :) ) http://www.precisionintl.com/Engine.aspx?ID=1730&EID=13086

Cool man Pushrods are pretty durable. Measure the lengths are consitant, roll test them on the bench. It's likely they are still ok. Might want to ask your cam grinder if they can overhaul your hydraulic lifters. They can definitely re-surface them (about $88). I managed to get VRS (valve regrind set) gasket kits easily enough. That's everything you need for the top end. It's likely you can get full kit that includes the bottom end also, being gaskets and seals. Crank and big end bearings are generally bought separately. Wait till you get your machine work done, as if they grind the crank, you will need undersize bearings and not standard ones. I recently bought ARP flywheel bolts as my engine is for racing. Rocket industries matched them up to a 4age set (yet to fit them). Take note of the welsh plugs sizes before you throw them out. Will need to know this info later on.

Do you happen to know what the respective 5k head combustion chamber volumes are for the 6cc and 25cc variants? My 4k bottom end with 3k head build, had to have the head decked a significant amount to obtain 26cc head combustion chamber.

I suggested the solid lifter conversion as I built a 5k once with a decent cam, power would fall over just before 6000rpm. I suspected lifter "pump up", but it could have also been lack of carburation on that setup. I also didn't like that the fixed rockers could mean rocker geometry could have been out if you deck the head and block etc, but i was lucky. Its nice to know you guys have pushed the limits without issues on my current build, i sent my cam to auckland cams in new zealand. Henry has 250 grinds in his computer for a k series. Haven't fired it up yet, so time will tell

Well, essentially you have a 4k with 80.5mm oversized pistons...a 5k. If i were in your shoes, I would try find some flat top pistons for the 5k, use the same cam, carbs, rods, etc out of your current engine. Convert the 5k to solid cam and use your 4k head and rocker gear.That should get the compression over 10.5:1 which is nice :) You should have a torquey little k series then

The thing is that you build a motor with changes to increase performance, there is no off the shelf carb(s) that are going to be the perfect solution. You need to have the right venturis and jets fitted to match what the new engine specs want. Only real way is to take the newly fitted carb on your new engine to a dyno tuner that knows carbs, and there aren't too many competent carby dyno tuners around anymore. The cam you have is fairly aggressive (good) so to get the gains throughout the rev range, this is necessary. I have a 40mm solex (twin barrel) on my internally stock 4k currently. Have gone through the jet amd choke change with my dyno guy and it runs well for a stocker. Will be going through the whole process again soon with twin 45mm webers on my race 4k (currently close to completeting my rebuild). Yes they are fun little builds these cars. :)

If you are using the 4k head, the ports are really small. If you use the 3k big port head, they are more ideal. Either way, Id be porting both or at least having 3k BP size. Its not the jetting, its the overall carb throat sizes that are likely to be restrictive. I would run a single 40mm sidedraght weber, or quad bike carbies if you want more upright carbs. If you want to maintain the downdrafts, maybe a pair of 34ICH webers?

Nice project Kyle. Glad you are going with the worked 4k option. Are you going to port the head? What valve lift is the cam? I think those carbies are going to restrict the other mods you are doing.

I like it. As long as you run the right chokes, jets and linkages, should br nice

Hey Dylan, Another thing that is quickly overlooked is working with the 4k engine. You may be surprised how much can be gained from these old motors. As above, you are likely to go through the rebuilding process anyway, so machinging and rebuilding costs are neutralised

Hi Guys Does anyone know what size the welsh plugs are on a 4k? I am referring to the 3 larger one on one side, not the 3 smaller ones Thanks

Thanks Gavin, I like the sound of your setup

Yes you should In the rear, you can use kyb's from a specific commodore wagon (covered on these forums). While your at it, best get an adjustable panhard rod as your diff will move off centre. Will need a wheel alignment to sort.

Hi Guys, I am wondering what type of ignition systems have found to be good for k series engines. I gather many would have nippon denso electronic dizzys, converted from points. Has anyone tried the Pertronix Australia conversion kit? Or used an MSD system to increase spark and have a rev limiter option? I'm building a 4k with 11.5:1 compression and twin sideraughts for mostly track racing. Am curious of the electronic ignition options of what has proven to be reliable and perform well

Has anyone experimented with oils on a k series for track racing use, where the engine is under constant stress?

Can build you a fresh 4k, stock or modified if you need?

Far out, those rods would be nice for the 4k I'm building.

I like where you are going with this...keep the updates coming

Did you try dropping a few squirts of oil down the spark plug hole, and comp test again? I would also turn the cams to base circle on both sides or TDC, and check the valves are returning all the way home. Might need a very light tap to see if they are siezed open. Call me if you need a better explanation

Wow......I love it!!

Maybe leaking valves on number 1 Hayden?

Around 3-5 kilos I'd say. Its comforting to know you didnt have a problem, though that is exactly what I am worried about. I have seen one let go along time ago and never forgotten lol! On another note, can you share some info about your engine? 9000rpm must have had a big cam and great bottom end balance. What power at *rpm? Cheers

Hey guys I'm looking for a lightened flywheel for our track car. By this I mean an original lightened unit, not a standard one that has been machined down. Does anyone know where I can buy one?