ben Posted October 29, 2004 Report Share Posted October 29, 2004 I have a 5k with just a bit of work done to it, 85hp at rear wheels at 7500rpm in a KE30 2dr sedan. I recently broke a valve spring as the cam has a lot of lift. Fitted new double springs with about 100lb seat pressure but chewed a lifter straight away. Replaced all lifters and runs ok again but to save the hasle of hydraulic lifters i want to change to solids. I know i have to have to cam hardened and that chev solid lifters will fit and pushrods i will change for 1 piece items of the required length. My question is: will the adjustable rockers from a 3k or 4k fit on the shaft of the 5k? I've been told that i might make an extra 10hp and an extra 500pm to be 95hp at 8000rpm as well? Quote Link to comment Share on other sites More sharing options...
Felix Posted October 29, 2004 Report Share Posted October 29, 2004 the lifters in my 5k have had the guts ripped out of them. the cup that the pushrod sits in has been dropped to the bottom of the lifter. it runs 3k pushrods and adjustable rocker gear from a 4k. Quote Link to comment Share on other sites More sharing options...
irokin Posted October 29, 2004 Report Share Posted October 29, 2004 Xany completely replaced the hydraulic lifters (as opposed to converting them) with holden six lifters I think they were. Xany can you confirm? Quote Link to comment Share on other sites More sharing options...
ben Posted October 29, 2004 Author Report Share Posted October 29, 2004 The lifters that i put in are holden 6 hydaulic lifters and they work ok. So the rocker arms from a 4k will fit on the 5k shaft? or do i have to replace the whole rocker arms, shaft and pedistals with 4k items? Quote Link to comment Share on other sites More sharing options...
Xany Posted October 29, 2004 Report Share Posted October 29, 2004 (edited) the lifters i used were out of a 253 V8 holden engine...same thing more or less. brand spankers, being solid as well. the 4k rocker gear *should* fit on. i used a 3k bigport head and atm i have a 4k rocker gear on there. so i'm guessing that the 5k head can't be much different. Just make sure the posts are about the same length or the difference in length can be adjusted through the rockers.....now if you were using a 3k head i'd tell you to look for some dastun A12 pushrods, they will fit in and adjust up nice. not sure on the 5k head mainly cause i didnt use it. Edited October 29, 2004 by Xany Quote Link to comment Share on other sites More sharing options...
Felix Posted October 30, 2004 Report Share Posted October 30, 2004 (edited) i run a 5k head, with the rockers and pedestals and shaft from a 4k. running the 3k pushrods (ones with shallow top cup), with my converted lifters, you have to back the adjusters quite a fair way off. the adjusters come very close to the rocker cover but don't hit it. the 4k rockers may fit on a 5k shaft. changing the whole setup straight over is far easier. there are a couple of different types of pedestals out there, steel (earlier) and alloy. they look to be different heights, but the rocker shaft sits at the same height in relation to the top of the head. this was discussed on the oldcorollas group ages ago. Edited October 30, 2004 by Felix Quote Link to comment Share on other sites More sharing options...
ben Posted November 1, 2004 Author Report Share Posted November 1, 2004 the 5K goes heaps harder with new valve springs and holden lifters, it was running a bit lean so i changed my float level on the weber and made more power again. My problem is i still have what sounds like tappet rattle occasionally and the engine misfires on acceleration every now and then. All the carb jets are clean and ignition is good. Could the spring pressures be too high for the hydraulic lifters as they are now at 100lbs? I don't know what else it could be unless the holden lifters don't work that well. Could chewing out the lifter damage the cam? The lifters are maintaining zero clearance ok so what else could make it run badly- i've only changed the springs and lifters. Could the lifters have too much preload with the new springs? I'm going to change to solids anyway but i just want to make sure it runs ok before i do that. I can get 4k rocker gear ok and will run chev solids with 1 piece pushrods. Very Frustrating!!!! Quote Link to comment Share on other sites More sharing options...
irokin Posted November 1, 2004 Report Share Posted November 1, 2004 Oh another thing someones neglected to mention. If you change to solids you will need to change the camshaft to a grind that is suitable to soild lifters. Easiest way to do this is grab a 4K camshaft. If your in Brisbane I have a spare one I could supply. Quote Link to comment Share on other sites More sharing options...
ben Posted November 2, 2004 Author Report Share Posted November 2, 2004 Thanks but i'm in Sydney at the moment! So i have to get the Cam hardened but also change the profile? How does the solid cam profile differ from hydraulic? I currently am running a single sidedraft DCOE 40mm Weber and when i've eventually converted to solid lifters i'm thinking about running either twin Webers or twin SU's. I'm a big fan of the Weber but would the SU's be any better? Quote Link to comment Share on other sites More sharing options...
irokin Posted November 2, 2004 Report Share Posted November 2, 2004 Redwarf our resident corolla rally expert upgraded from twin SUs to twin 40DCOE webers. I'm not sure how the profile differs...only that it does. I have a feeling its to do with the ramp rates but I'm unsure how hydro lifters work... Quote Link to comment Share on other sites More sharing options...
ben Posted November 2, 2004 Author Report Share Posted November 2, 2004 Yeah, I think i'll stick with the Webers, twin 40s should go alright. I'll get the cam hardened and i guess whoever does that can keep similar specs but on a solid cam. Quote Link to comment Share on other sites More sharing options...
irokin Posted November 2, 2004 Report Share Posted November 2, 2004 Yea any cam shop should be able to recommend the cam profile. Tell them exactly what you have including the carbys and what you want. Quote Link to comment Share on other sites More sharing options...
Felix Posted November 2, 2004 Report Share Posted November 2, 2004 (edited) for a street engine, twin SUs are better. they offer better allround performance and economy. ask Redwarf what sort of fuel economy he gets in normal driving with his webers :jason: i'm sure it is less than he got with his SUs. remember his car is a competition vehicle and not a daily driver. webers are better suited to a race engine, as they are setup to work best over a narrower rpm range than with SUs (choke selection dependent). the SUs due to their CV (constant velocity) design give better throttle response at lower throttle openings. webers generally give an extra few percent power in the topend. SU's give extra power throughout the low to midrange, with better response and economy. think about the sort of driving you do and choose from there.....i know about 90% of my driving is just commuting around town. i have done a lot of research trying to find the difference between a hydraulic and mechanical cam. apparently a mechanical cam has more of a gentler ramp onto the flank of the cam lobes (to take up valve lash) than what a hydraulic cam does. i have read of some people saying it is fine to run a hydraulic cam with solid lifers so long as you have tight valve lash adjustment. some people say you need a new cam........i am going to try this for myself, i'm putting the hydraulic cam that was in my 5k into my old 4k that is going into bec's ke16. i'll tell you how it goes. Edited November 2, 2004 by Felix Quote Link to comment Share on other sites More sharing options...
ben Posted November 2, 2004 Author Report Share Posted November 2, 2004 I will agree that the Weber does lack in low end power and torque but when the revs are over 4000 it just pulls very well. Fuel economy however leaves a lot to be desired, especially given that i drive it to work every day. I have twin SU's that came off an 18R engine out of the coronas. However i don't know where i can get a manifold from to fit the 5K. What needs to be changed on the SU's if i put them on my 5k from an 18R? Quote Link to comment Share on other sites More sharing options...
Redwarf Posted November 2, 2004 Report Share Posted November 2, 2004 (edited) Twin webers are good, but the words "fuel economy" should never be used in the same sentence. Felix is right, I had HS4 SU's on the Dwarf and found them to be really good user friendly carbs. Good usable power from down low, with reasonable fuel economy. A good dyno I would consider essencial to make sure that needle selection is correct (mine were leaning out quite badly). Economy wise I never quite worked it out, but I got the whole of Rally of Queensland which was about 400km of transport, 140 km of reccie and 100km of balls out competitive out of under 100 litres. I know with the twin 40's, I work on 8kms per litre on transport/ reccie and 3kms per litre competition maximum. This is fitted to a fairly grumpy 3K. The webers will give you better torque and slightly more hp, but it comes at a price. If it was a daily driver, I'd go with the SU's. For what it's worth! Cheers R Edited November 2, 2004 by Redwarf Quote Link to comment Share on other sites More sharing options...
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