Jono.C Posted June 28, 2011 Author Report Posted June 28, 2011 Okay. So another question, Just thinking then that the holden/ datsun combo is for a solid lifter conversion on a 5k with a 5k head But what about for a 4k head on a 5k block? Because, Isn't a 5k block the same height as a 4k one? and with a 4k head couldn't you just run the 4kc cam pushrods lifters and head with valve gear and be done with it? Quote
Taz_Rx Posted June 29, 2011 Report Posted June 29, 2011 Mine is 5k bottom end / 3kbp head :wink: Quote
tojo2 Posted June 29, 2011 Report Posted June 29, 2011 (edited) Isn't a 5k block the same height as a 4k one? and with a 4k head couldn't you just run the 4kc cam pushrods lifters and head with valve gear and be done with it? Yes same height block but 5Ks have larger diameter lifters so can't use 4K lifters Edited June 29, 2011 by tojo2 Quote
GJM85 Posted June 29, 2011 Report Posted June 29, 2011 Okay. So another question, Just thinking then that the holden/ datsun combo is for a solid lifter conversion on a 5k with a 5k head But what about for a 4k head on a 5k block? Because, Isn't a 5k block the same height as a 4k one? and with a 4k head couldn't you just run the 4kc cam pushrods lifters and head with valve gear and be done with it? Yes the block height is the same. No you cannot use 4k lifters in a 4k block because the lifter bore is a different size. The holden lifter and datsun pushrod combination is a tried and tested combination for what your trying to achieve. Do you have a shallow or deep dish piston 5k engine? The deep dish (D-shaped) 5k has a shallow combustion chamber in the head. That head is 6mm shorter in height than the shallow dish (O-shaped) engine. If you have the shallow dish engine using a 4k head won't lower compression as the heads are almost identical. Here's a diagram I drew sometime ago, if you can understand what i've tried to display. Quote
Jono.C Posted June 29, 2011 Author Report Posted June 29, 2011 I've got the D dish 5k and Intending on using a flat top 4kc head Quote
GJM85 Posted June 29, 2011 Report Posted June 29, 2011 I've got the D dish 5k and Intending on using a flat top 4kc head Ok then your sweet. I wracked my brain for weeks trying to understand the in and outs of this conversion. Use the 202 lifters, a12 pushrods, 4k head and adjustable rocker gear. Get your cam reground to suite solid lifters and you'll be sweet. Quote
Jono.C Posted June 29, 2011 Author Report Posted June 29, 2011 I've got a complete 4k under the house i'm stealing parts from, Can i just use the 4kc cam rather than having the 5k one ground? Quote
Crostek Posted June 29, 2011 Report Posted June 29, 2011 (edited) Hi I have a 3k big port head on a 5k block with 4k a rockershaft and pushrods, Landcruiser lifters, and Modified Harland Sharp "A series" 1.5 ratio 1257 roller rockers. I went for the Landcruiser lifters because they are lighter then the holder ones, You can by the lifters from REPCO, trade price is around $12 each, I will dig through my dockets and get you the part number if need. I also have some A12 push rod's if you need them as I am not using them Edited June 29, 2011 by Crostek Quote
GJM85 Posted June 29, 2011 Report Posted June 29, 2011 (edited) Can i just use the 4kc cam rather than having the 5k one ground? Absolutely. If you come across second hand lifters you should have them refaced before you use them. Edited June 29, 2011 by GJM85 Quote
Spencer[RL] Posted June 29, 2011 Report Posted June 29, 2011 I got quoted $24 each from Holden for a AT992 GM Chev and Holden solid lifters! :bash: And $12.99 each from Repco I'm going to get me a set of them crow cam ones and still have half a set :) Quote
SLO-030 Posted June 29, 2011 Report Posted June 29, 2011 Hi I have a 3k big port head on a 5k block with 4k a rockershaft and pushrods, Landcruiser lifters, and Modified Harland Sharp "A series" 1.5 ratio 1257 roller rockers. I went for the Landcruiser lifters because they are lighter then the holder ones, You can by the lifters from REPCO, trade price is around $12 each, I will dig through my dockets and get you the part number if need. I also have some A12 push rod's if you need them as I am not using them So, the landcruiser (1F?) lifters have the same base thickness as the 4K lifters and the right diameter for the 5K lifter bores? Also, what was modified on the rocker arms? Quote
tojo2 Posted June 29, 2011 Report Posted June 29, 2011 and Modified Harland Sharp "A series" 1.5 ratio 1257 roller rockers. Interesting - what needed modifing ? Quote
Crostek Posted June 30, 2011 Report Posted June 30, 2011 Interesting - what needed modifing ? Things you need to change are The centre bearing bushing to suit the 4k rocker shaft, The thread for the adjuster screw has to be changed to metric M8, or you need to buy the "mini" imperial adjusters and nuts then modi the ball to fit the 4k push rod cup. you will also need to run a lash cap as the rocker are is 1.5mm shorter than the Toyota one and under high lift there is a chance that the roller will fall off the edge of the 6mm valve. I have also asked them if they can do these modifications to the base product for me and how much per each set once done. Just awaiting an answer Quote
tojo2 Posted July 1, 2011 Report Posted July 1, 2011 Things you need to change are The centre bearing bushing to suit the 4k rocker shaft, The thread for the adjuster screw has to be changed to metric M8, or you need to buy the "mini" imperial adjusters and nuts then modi the ball to fit the 4k push rod cup. you will also need to run a lash cap as the rocker are is 1.5mm shorter than the Toyota one and under high lift there is a chance that the roller will fall off the edge of the 6mm valve. I have also asked them if they can do these modifications to the base product for me and how much per each set once done. Just awaiting an answer Have heard of minipeople using K rockers for a cheap 1.5 ratio mod. but didnt know how related they were . Cheers Quote
sliesh Posted July 3, 2011 Report Posted July 3, 2011 sorry to throw a spanner inthe works. 5k D dished / 4k head < head 6mm higher / 202 solids / a12 push rods / 4k rocker gear (adjustable) < ok i understand 5k flat top / 5k head / head std height / < CONFUSED what do i use. would the 6mm from the head effect this? how do i compendsate this. also please take note id like to use a 4k reground cam thanks can any one help? thanks........... Quote
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