cam question 4.0

[bails85]

hey guys need a little help. my buddy just had his motor rebuilt and he had the guy who put it in install a bigger cam. well now there is a ticking sound and the guy who installed it said that because of the new cam he needs roller rockers. he said he needs a them with a 1.5 to 1.6 ratio with 7/16 studs. any of u guys know where we can get these. and second of all is this correct. he is a garage builder so im not sure about all of this. just trying to help my friend out. yes i warned him. lol

[Jeeperator]

What? different ratio rockers wont get rid of the ticking unless they were not adjusted correctly in the first place. Sometimes when swapping out to a bigger cam different length pushrods are needed and if they are too short they will tick. It also depends how much bigger he went, more lift or more duration or both. See if he can run it a short time with the valve cover off to find which one is ticking and try readjusting it if it is adjustable. Summit is a good place to buy any performance parts but be careful sometimes 1.6 ratio rockers can cause the pushrod to hit or rub the head make sure you check your clearence with 1.6 rockers. I personally would of picked a cam with more lift instead of running higher ratio rockers.

[2blk2drs]

Is this ron's cheap stroker by chance?

[bails85]

no its not rons stroker. my friend had a guy that rebuilt his brothers dodge motor rebuild his 4.0. the guy rebuilt it with forged pats and all that stuff but my friend wanted a bigger cam for more power. when it started ticking my buddy took it to him and asked wtf the noise was. he said that stock rockers wont accept the bigger cam because they are not adjustable so he has to use adjustable roller rockers. he told him that he needed 1.5 to 1.6 ratio with 7/16 studs. thats all i know. im just trying to find out where he can get these at. the guy eric has built quite a few motors that have ran very well but he has only messed with a few jeep motors. it runs great minus the ticking. i dont know anything about this at all so thats why i rebuilt my motor stock. we looked at summit but they were pretty expensive so we just wanted to know if u guys knew of others that might be a little more pocket friendly.

[lakev2]

did he replace the lifters at same time as cam? and did the owner of engine break in the cam properly? From what i have read on cam swaps in 4.0/4.2 engines the cams are sensitive to lifters and proper break in.

[Jeeperator]

He rebuilt the engine I am sure he replaced the lifters, its a must and usually comes with the cam. Ok I see! I was wondering if the rockers were adjustable or not. Running stud mounted rockers will probably fix the problem. But running a little longer push rod might also. Figuring what length is a whole different story with out the proper tools. The reason they are to short is when the cam is made bigger the base circle is ground off and the lift and duration ends up being bigger. But since your base circle is smaller your pushrods need to bee longer or your rocker arm adjustment nut needs to be adjusted further down to make up the difference. I would run the 7/16" stud mounted roller tiped rocker but proper valve train geometry should be checked because he still might have to change the pushrod length.It all really depends how big the cam is. Try summit for those rocker arms. When I breakin a cam in I not only use the break in lube but I also use heavy duty diesel motor oil like delo or rotella 15w-40 because it has a higher zinc content that helps lubricate the lobes better during breakin.

[bails85]

good info. but like i said i dont know what all the guy did. but i do know he has built a few solid motors. he reccomended to get the adjustable rockers so that what were looking for. tried summit but they are pricey. anywhere else to get them at?

[RAT]

good info. but like i said i dont know what all the guy did. but i do know he has built a few solid motors. he reccomended to get the adjustable rockers so that what were looking for. tried summit but they are pricey. anywhere else to get them at?

Are you looking at aluminum or stamped steel rockers? big diff in price. I have to ask; why did the builder put a big cam in and NOT tell your buddy about the need for different rockers/lifters before hand? Wierd if you ask me.

If you change to stud mounted rockers it gets more expensive. Stud kit, rockers, push rods, all that starts adding up.

[Jeeperator]

I have bought alot of parts over the years and Summit or Jegs always seems to have the best prices. You might find something on ebay also. I went to a local performance shop and not only was the same exact part at least 20% higher in price they also had to order it(probably from summit). Performance parts are not cheap if he cant afford the rockers and studs and not knowing the size of the cam the longer push rods are probably your only cheaper alternative.You can probably figure out how much longer you need by reading the cam card. Have him ask the builder if that will suffice.

[bails85]

i have no idea kurt. my buddy requested the bigger cam and the builder put it in for him. jeeperator good info but the problem is that the guy who built the motor is the one who knows about the motor and the one who has to fix the problem. if not my buddy has to go spend more money to have someone else do it for him.

[Jeeperator]

I am just trying let you know a possible cheaper alternative that can be dicussed with the builder then buying studs and rocker arms. I agree the builder should fix the problem.

[bails85]

i appreciate all ur guys help. were gonna just let the guy who built it deal wit it.