Viterbo

Banjo the Starlets had that thermostat housing with the hole because it's where they have the temp sensor for the electric fan

Condenser also good? Changed mine almost 2 years ago and they keep going. But I guess components aren't just as good as they were... On the electronic dizzy matter I'm currently developing this:

Need a few more hints on this build: - I'm going to buy new lifters (3F ones). Is it worth buying new pushrods? (if they're available). I already have a few sets of used 4K pushrods, wondering if buying new ones is worth it. - Been reading a lot about breaking in a new flat tappet camshaft. Mostly regarding V8s but I think K engines are also flat tappets? What do you advise doing to break in a newly built engine (rings, bearings, etc) with a regrounded camshaft and new lifters? This is what I think is correct - Make sure the engine will start right away. Carb full of fuel, oil circuit full using an electric screwdriver on the pump (or using the shaft of an old dizzy). Instantly rev it to around 2000rpm and let it bounce between 2000 and 3000 for around 20 minutes. Replace oil and filter after this. Then go make around 100kms applying little stress to the engine but letting it go down the rev range but itself to create vacuum so it seats the rings. Use an oil with a lot of zinc. Anything wrong until this point?

Is it something like this?

Also my carb is a 28/28, some of them are 28/32. I'm going to try to get a bottom with the 32 butterfly

I think my primary is 0.9 or 1.0 and not sure about the secondary. I'm not having any trouble on revving honestly. My timing is set to 5 degree to avoid detonation (which I think still occurs on 95 RON). I can rev it to 7k easily. The issue is when rolling in highway for example, 4th and 5th at higher speedsjust seems the engine struggles a lot. I can floor it and it doesn't go any faster. That's why I thought the carb just doesn't give enough for it to go further. I know these engines aren't really performance oriented, but..

I already have a narrowband O2 sensor and a cheap ebay digital gauge to install on the car, but it's not yet installed. I want to fully rebuild and tune up the engine at the beginning of Spring and it'll run on bike carbs, but in the meantime I want to run the engine safe. One thing I notice is that the engine struggles a lot in higher revs, like there's not enough amount of fuel mixture going in...

I'm running a carburetor from a 4K engine in my 5K and since I'm running a bit of compression (12,5 bar in each cylinder) I'm afraid of running lean. Did anybody drill the jets of the standard carb? Is it worth doing? What sizes should I run? It's a standard 5K with just the compression and slightly ported on the intake side.

That helps a lot altezza, thank you! Anything on the exhaust side?

Was told 3K-B bigports have 30mm intakes and the maximum the head holds is 33mm and it's already taking a risk. 4Ks are 28mm and my head is already +2mm. Maybe going 31 or 32?

The last piece of info I'm still missing is how much to enlarge the intake and exhaust ports. I tried a gasket on a stock head and the gasket holes are the same diameter as the stock ports, so I can't really gastket match them.

Regarding engine starts after a filter change, I always disconnect the plug from the ignition coil so it can't start due to no spark, and then I crank it until the oil pressure light goes off. Only then I start the engine.

I think you mean 90 degrees Banjo?

What needs to be done to the A15 valves besides recutting the valve seat? As far as I know they're 3mm longer? I don't have access to Holden or Chevy stuff as people usually use.

Great. Anything on the exhaust ports? Tho they're square... --------- Kent Cams sent me info about duration @1mm for both T124 and T125 T124 - 220º T125 - 232º Seems a bit low for such agressive cams. I think I'm going the Catcams route as they have lots of regrinds. Something not above 275º and with good duration at 1mm, like the Camtech 609 that altezzaclub showed me.

Joshua do you have the diameters of the ports? Catcams sent me this datasheet related to a camshaft. What do you guys think? Duration at 1mm I guess it's the same as your .050

Yes Esapeltonen. A portuguese guy is tuning a 3K to reach around 130hp (he tunes Datsun A12 engines for the National Classic Championship) and bought a lot of stuff from Esapeltonen recently.

What about the combustion chamber? Polish or not?

There is in fact a Finnish website with performance parts but they only have available 7mm stem valves, that's why I thought 4K valves were 7mm stem. Already contacted Kent Cams UK to provide me more in depth info on the T125 camshaft, and asked for the duration data at middle lift.

I think the T125 has the need for dual valve springs but on the other hand doesn't have the need of me sending my stock cam for regrind. Would an adjustable pulley be needed with the 125? About the Datsun oversize valves, I find contraditory information regarding the stem diameter. In some places I find A15 valves with 8mm stem and in other places I find A15 vales with 7mm (same as 4K stem). Would a machine shop be able to find suitable valves?

I get it, I'm gonna contact Kent and ask for diagrams with more deep info. Thanks My head currently has the moulding lines shaved and a rough polish. Maybe I'll open the ports to match the gasket and keep this kind of polish I had a big trouble that was the noise they were making and I suspect they were not working as they should. The 5K wasn't sold in Portugal so it's very difficult to source specific parts. I prefer buying new solids than new hydros

Really? I have around three 4Ks twin squish disassembled, so I have a few sets of their pushrods. That's good news as I will only need to buy the lifters

Thanks tezza, I'm gonna take a look at Tommy's build! What pushrods can I use with the 3F solids? In Portugal we have 95 and 98 RON. Do you think it's worth going with the Datsun valves? As for duration and lift I'm gonna present you a print from the Kent Cams catalogue with the camshaft data (T124 "Sports R" and T125 "Competition").

I'm planning a tune up rebuild on my 5K and I'm gathering some info, so I'm going to ask a few questions. It will be mainly a road car with some hits at the track and other racing activities. This will be done to an European 5K, dished pistons with twin squish head from a 4K. Head (including camshaft and rocker gear) Intake and exhaust ports will be ported and polished. How much do you advise porting each of them? I heard 1mm bigger valves can be fitted without changing the valve seats. Is this correct? Is it worth the money going bigger than that? I intend to send my camshaft to Kent Cams UK so they can grind it to T124 specs as they don't sell it anymore. Worth going to T125 (no need to send my own)? (specs attached). What about Adjustable Pulley and Springs? I made a DIY conversion from hydros to solid lifters but I'm not happy with it. I want to buy solid lifters from Toyota for the 3F engine (same as 5K). What pushrods can I use? As for compression, I don't know my current compression ratio but I'm getting around 12,5bar per cylinder and I'll probably keep it that way. Block Block will be almost stock. Stock rods and pistons, crankshaft will be a lightened and polished one. Have a dual row timing chain setup. Have a lightened flywheel (around 5kgs). Is it worth to put the washer in the oil pump spring? I thought on polishing the rods, worth it? What do you think about an oil cooler? I'll be using quad CBR600 36mm Keihins. What I want is a balanced engine that I can use at the track and at sunday sea trips. What power can I expect? I was aiming to around 110/115hp at the crank. I've read almost every guide available online but real feedback on the parts I have and want is more useful to me. Thanks to anyone who spends some time to answer me. All machine work will be done by a professional shop.

That only works when revving. At idle it does nothing.