ikon_idol

Hi. My 7k crank looks similar (but stronger/thicker here and there) to a 4k/5k in that its balanced in the same way. Its counter weighted and balance drilled in the same way a 4k/5k crank is. It has a longer stroke than the 5k and the actual crankcase and oil pan is a little wider for this reason. By the look of it very little drilling and grinding was needed to re-balance.

What he said! :) Also, I don't think a 7K crank can be be put into one of the smaller K blocks. It's longer stroke crank looks like it would hit the sides of the smaller block. This is why the 7K block is wider.

Hi. Geez, never had one burst into flames! A cheap solution maybe the paper element "pancake" style filters used on some of the old Triumph Spitfires that had HS4 carbs. The used to cost about $28 each.

Hi. I used Ramflow filters made in Australia. Search "Ramflow" and you can (or could) order on line. They work and fit very well and the replacement filter elements are cheap. The air filter bodies are made with a range of different mounting off sets to suit any clearance problems. Its a while back but I think they cost about $40 each. There is an ebay seller that stocks them too. Look under MG in the car section.

Hi. I ran a pair of 1.5" Hitachi SUs (off a Datsun 1600) which look like a copy of the HS4 1.5" SUs used on MGBs etc. on my 5K engined race car for a while. I put rebuild kits into them and left the standard needles in place. I used an electric pump and regulator set to 2.5 psi. They ran very well after road tuning and balancing them, a little rich in the mid range but no flat spots and good throttle response. I used 10W30 oil in the dampers. I'm sure I could have got them better on a dyno and exhaust sniffer Cold starts were not as easy as with the old webers. When I put the rebuilt Webers back on there was a performance gain but not that much. I'd be happy with a well tuned set of 1.5" SUs on a warm 5K.

Yep. I don't know what kind of 7k people are talking about but 3,4,5K sumps don't fit. The 7K block is about 10mm wider so the studs just don't line up with the holes in the oil pan. This wider block is also the reason why the engine mounts don't line up perfectly. How do I know this? I've got 5K and 7k motors and I've had them in and out of my race car.

Nice welding.

Hi. Different pistons to the ones in my 7k. Mine have a "D" shaped dish like 5k pistons. Are these standard? How did you convert to solid lifters? I left the hydraulic ones in my 7k and used solids in the 5k. I converted them by pressing a hardened steel push rod seat into the bottom of a gutted 5k lifter. Paul

Hi. Good work I notice you are using a Stromberg CD carb. Is it using the standard metering needle and jet or did you have to modify them to get the A/F mixture right? Paul

The 7k I'm building is finished only to the short block stage. Its on the back burner for a while. I've recently finished a 5k engine build to replace the one in my sports car. That engine is going in first, lots of work has gone into that one. I never planed on building a 7k but this one come up by chance after I was well into the 5k rebuild. I didn't need it but you know what its like. The car is very light, about 580kg, so it should fly. Paul

Sorry Nick, I missed your point. Yes the standard, +0.25 and +0.50 bore sizes are the same as the 5k and I known for a fact that the 5k rings fit my 7k pistons. I'll try to take a photo of the pistons side by side and post them. My 7k came from an engine exchange place and appeared to be well stuffed. So much so that they didn't even want to rebuild it. They installed a low km import for $2,200. The owner of the Town Ace had not changed the oil even once after the first service, only topped it up! 120,000km later it was drinking oil and making clunk, clunk noises. There wes no compression but it turned over ok and the clunk sounded like the cam chain. I took the chance and paid $400 for it as is. When I pulled it down it was so sludged up it was hard to believe. It was like a thick coat of tar gone solid on everything and it smelled really disgusting. Main problem was blocked oil return holes in the pistons and rings so badly stuck with hard sludge I had to break some of them out. The cam chain tensioner had worn through and was seized, the chain left to bang around. Hard to believe it ran at all. Crank, bores and pistons were fine after a clean up. The engine shop that hot dip cleaned the block prior to light honing it said they had never seen such a filthy sludged up block in 30 years of engine reconditioning! Tough little engines. Paul

No, pistons don't interchange with 5k type. Different pin height, pin diameter and dish volume. Only the rings interchange, same ring grooves but for oil return holes instead of slots. Paul

Hi. I've got some piston info for you. Pin height is 33.8mm. Pin diameter is 20mm and pressed into rod. Piston "D" dish volume is 23.5ml. Piston rings interchange with 5K ring sets. Hope this helps. Paul

Hi. I'm building a 7k at the moment. You can't use 5k pistons because the 7k pistons have a different pin height and a larger pin diameter. Also, it has a larger dish volume. If you find a non Toyota piston that fits let me know. The thrust bearings in the ACL catalogue are wrong. They specified the same p/n as the 5k thrusts which don't fit. The ones that fit are the same as the 7A engines. They may have fixed this by now. I went for a Wade hydraulic cam profile with about 1.5mm higher valve lift and 20/60 60/20 timing. You may need to machine the valve pockets in the pistons deeper to clear the higher valve lift, you need to check this during assembly. Get an adjustable cam wheel set (Rollmaster make one) and degree the cam timing in carefully. I had the flywheel lightened a little and the pressure plate. flywheel. crank and pulley balanced after I matched the piston and rod weights. Paul