5K Build Stupid Questions That Need Answering

[springersrolla]

Hey guys righto paint the picture I'm building a 5k that has a 5k dish head with 5k flat top pistons that have been machined to 11.6:1 cr. Have had the head skimmed to bring everything up wth cr to 11.6. Have measurements but not on me at the moment. I am running 3f solid lifters in replacement of hydraulics with later model 4k adjustable rocker gear under direction of my cam builder requiring more clearance on my exhaust valve with the compression hence the need for custom rods.

 

Questions i have 1. Cam builder has said to run in cam with light weight springs- can anyone suggest a suitable spring, should i be looking at coil bind or spring rate? I'm running double valve spring and once again don't have the measurements with me, can i remove the inners and run the cam in or should i look at a light set to run? Cam builder has suggested what spring rate to run as normal motor and the doubles meet that.

 

2. I'm looking at dialing in the cam in, and once i have tdc I'm going to use my old 3k pushrods that i have cut a section out of and made into adjustables, is valve wipe the crucial part here, or should i be looking for a medium on my adjustment threads. Also is it ideal for me to take a mill to my rocker posts to suit the cut off the base circle of the cam to get more accurate??

 

3. Once i assume my rocker post/valve wipe is correct I'm looking at buying a set of 4140 chromemoly rods to suit the motor. If i degree this assumed length with adjustable pushrods theoretically everything should be correct and i have no more dramas?

 

Is there anything else valve train related that may catch me out and i need to look out for? Apart from painting my engine bay and fitting carbs the motor will be ready to run.

 

Any advice is greatly appreciated and can get measurements if needed. Cheers

[TOMMYS Ke 11]

If you haven't already ! remove the springs between the rockers and get brass/stainless steel sleaves made up as the TRD motor has , we did this on Thomas motor it helps keep the rockers directly over the valves and stops the from floating sideways . Don't make them to tight that they bind when engine gets hot I hope this was of some benefit for you . If you like you can see them in Thomas build thread :thumbsup: . Cheers:- Stuart :wave:

[kickn5k]

Ok trying to keep it short as I'm fishing/camping atm and have little reception.

Run-in cam with only the outer valve springs fitted.

 

Stu's spacer suggestion is a good idea, definitely keeps them more stable.

Edited September 24, 2015 by kickn5k

[springersrolla]

Thanks for the responses and sorry stu for interrupting the camping trip. Was gonna pm but glad you chirped in. Thanks tommys ke also. Head has new valve guides, all is good there. Will run the outers only in the cam bedding process. Main concern is how to work out best pushrod length once i have tdc and whether or not valve wipe or rocker adjustment is ideal/milling rocker posts to base circle adjustment. Man thanks stu. Camping and still checking rollaclub your as bad as me:) thanks in advance

[GJM85]

You should not need to adjust rock post height. The cams base circle difference can be compensated with your adjustable rockers and even custom pushrod length.

I can tell you right now though.... You will need a cup and ball pushrod of 150mm.

[springersrolla]

Thanks gjm, yeah I'm getting cup and ball pushrods made. I figured as much with the rocker posts/compared to using the adjustable thread. My pushrod measure was actually 177.5mm roughly 7". Thats with 3f lifters in a d dish head. Whats the 150mm from??

[GJM85]

Yeah I didn't account for your 3f lifters. 150mm would be with chev lifters.

 

[joshua.mathews]

U should be only running 80ponnd seat pressure spring