megamannz123 Posted October 4, 2013 Report Posted October 4, 2013 Ok all you engine gurus, I just spoke to crow cams and they suggested the cam below for my needs. They mentioned that I would need to change to a 4k head/adjustable rockers to use this cam due to the high lift. I want to stay with the 5k head as it has been restored etc. so can I just get different length push rods to suit once the cam is in or should I fit the 4k adjustable rockers to my 5k head. Ideas? Quote
springersrolla Posted October 4, 2013 Report Posted October 4, 2013 I'm in exactly same boat as you. i have a 5k bottom end. hydraulic lifters and hyraulic cam and a well ported 5k head. i will not change heads due to the porting already done. ill be using 4k adjustable rocker gear and i have measured the distances between 5k pushrod and lifter. and 5k gutted lifter with the cup back in and 3k pushrod and measurements are pretty close. i have been told there is oil pressure issues and grub screw is needed to block off oil. i can't get any concrete info on 5k head and block with what setup . it all seems to be use 4k head Quote
GJM85 Posted October 4, 2013 Report Posted October 4, 2013 What type of 5k head? And what pistons are being used? Quote
springersrolla Posted October 4, 2013 Report Posted October 4, 2013 shaved 5k with lugs under 1 &4 and d shaped pistons Quote
GJM85 Posted October 4, 2013 Report Posted October 4, 2013 You need 150mm pushrods and non-adjustable rocker assembly to run hydraulic lifters. Quote
springersrolla Posted October 4, 2013 Report Posted October 4, 2013 i want to run solids i have all hydraulic gear Quote
megamannz123 Posted October 4, 2013 Author Report Posted October 4, 2013 (edited) Yup I have the exact same setup. Rebuilt 5k bottom, 5k head shaved to a 13cc combustion chamber, 22.5cc d dish piston, running a .8mm head shim. Comp at 9.7:1 So can I run the adjustable rockers from the 4k head with the hydro lifters and big cam. Couldn't I just set the tappet clearance to none? Won't that just be like having non adjustable tappets like the original 5k ones? Edited October 4, 2013 by megamannz123 Quote
GJM85 Posted October 4, 2013 Report Posted October 4, 2013 You will need ball and cup pushrods 150mm long. Quote
springersrolla Posted October 4, 2013 Report Posted October 4, 2013 hey gjm how did you work that out?? just running off lifter lenght and 5k pushrod length? I'm still stumped to how to run 5k solid lifters, probably from a 3f cruiser, then I'm thinking 3k pushrods and 4k adjustable rockers. you think that will work?!! cheers Quote
springersrolla Posted October 5, 2013 Report Posted October 5, 2013 measured my 5k hydro pushrods (ball and ball) they come in at 150.9mm. datsun a12 are 152mm according to google. ive just picked up some 3k cup and ball rods and am thinking of running the gutted hydraulic lifter with 4k adjustable rocker posts but am worried about loss of oil pressure. trying to get ahold of 3f lifters to run some measurements. any reason why you wanna run hydraulic cam and lifters?? Quote
GJM85 Posted October 5, 2013 Report Posted October 5, 2013 This is a lot to get you head around at first but you can work with it. There are 2 hydraulic 5k's & 1 solid 5k. Yours. Deep piston, 76mm shallow combustion head(same as 4k-u), hydraulic lifters, 150mm ball & ball pushrods. Mine. Shallow piston, 82mm deep combustion head(same as 4k-c), hydraulic lifters, 156mm ball & ball pushrods. From all data I've come across the 3f solid lifter is assumed to be the same as the 5k solid. I have not seen or read anything that has confirmed that tit bit. I've never seen one or seen images of the 5k solid lifter/rocker gear. It could almost say it's mythological. Datsun a12 pushrods are 152mm and work great with chev small block solid lifters. People say 202 solid lifters but all 202's ran hydraulic lifters. Anti-pump hydraulic lifters were designed to replace hydraulics in performance applications to eliminate lifter float at high rpm. My set up is shallow pistons, 4k-c head, 202 anti pump lifters, a12 pushrods and adjustable rockers on a solid cam. I run 0.10mm valve clearances. Any more and it rattles. In my next build ill run hydraulic. Any rocker adjustment required due to cam lift will be countered by shaving or shimming the rocker posts accordingly. Quote
GJM85 Posted October 5, 2013 Report Posted October 5, 2013 If you we're to put a 2mm shim under your 4k adjustable rocker posts and used the a12 rod and chev combo you may have the clearance and adjustment to get away with it. Quote
GJM85 Posted October 5, 2013 Report Posted October 5, 2013 You could even have to a12 pushrods machined down a few mm as they are a solid item. Quote
springersrolla Posted October 5, 2013 Report Posted October 5, 2013 see ive always wanted to stay hydraulic but alot of people and tighe cams have also told me that solids is where its at. then you hear the likes of philby and coln72 and these lads swear by running hydraulic lifters. originally i wanted hydraulics for ease of operation but got nervous with tolerances with high lift cam and big compression. ive talked to my engine builder and hes encouraging solids also. i think about keeping hydraulics and giving them all a good cleanout, but when i gutted the 5k hydraulic lifter, put the top cup back in and measured the 3k lifter with it, it identical length as the 5k rod with hydraulic lifter measurement uncompressed. i don't know what to do Quote
GJM85 Posted October 5, 2013 Report Posted October 5, 2013 If the gutted 5k lifters and 3k rods work, use it. or you could run chev solids with a12 rods. The could be machined down. Quote
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