1.6 or 1.7 RR Question

[89RedFoxGT]

Well, Heres what I plan on running as far as my set-up and wasnt sure what RRs to run with it.

ported and shaved E7TE heads
B-303 cam kit
Dual springs/moly retainers and keepers
lower ported by T-moss
and either 1.6 RR's or 1.7, wasnt sure which ones??

also wheres a cheap place to buy them from??


and one more question, Were Can I buy a electric fan for my car at? I have and electric fan off my brothers blazer its like a 17" fan I think, Woiuld it be bigg enough to keep it cool?

Thanks yall!

 

[thumper460]

Keep the 1.6's !! less wear and tear on the valve train, if you want more lift get a higher lift camshaft.. the X303 is 224 @.050 same centerlines.. only lift is 542 vs the B's 480" cool?? and YES install the X as I suggested installing the B !! cool??

Just me.......................................

Thumper

 

[GT_Rich]

I'm just curious as to how 1.7's produce my drivetrain wear and tear. What's the theory there? Thanks!

 

[smr]

Lincoln Mark VIII fan from EBAY....one of the best fans you canget and shoudl run you under 200$ including wiring and everything....

 

[dragnazz5.0]

I'm just curious as to how 1.7's produce my drivetrain wear and tear. What's the theory there? Thanks!

not really sure...since putting 1.7s on and getting more lift is in essence the same as putting a bigger cam with more lift. maybe im missing something

 

[thumper460]

the bigger the rocker ratio.. the MORE side loading on the valve and valve guide.. esp at the top.. does it mean that the valve train is going to trash its self in a month or two... nope!! it means that there is wear issues and the sideloading also pull HP.. a lot of HP?? Nope... get the idea.?? get the right cam and the right rocker ratio..

Just me.....................................

Thumper

 

[dragnazz5.0]

the bigger the rocker ratio.. the MORE side loading on the valve and valve guide.. esp at the top.. does it mean that the valve train is going to trash its self in a month or two... nope!! it means that there is wear issues and the sideloading also pull HP.. a lot of HP?? Nope... get the idea.?? get the right cam and the right rocker ratio..

Just me.....................................

Thumper

that works for me. i always like learning something new. i just figured it wouldnt make a difference. i know some of the nascar teams are running close to 2:1 rocker arms just because they cant put a big enough camshaft in the block. but they only have to last 500 miles

 

[Chietala]

Might wanna double check the clearance with the lift on that "x".
especially with shaved E7's . To be honest I dont think thers a reason to be that big with E7's.

Also I dont think you'll have any issues with 1.72's under 7000 rpm and 450hp. Get your self some good roller rockers and hardend push rods.

I'm personally running b303 W/1.72s E7's.
Im in the middle of a rebuild/head upgrade so now Im looking for a higher lift cam.

 

[GT_Rich]

"my" in my original post was supposed to be "more". Anyways, thanks for the input.

 

[89RedFoxGT]

Keep the 1.6's !! less wear and tear on the valve train, if you want more lift get a higher lift camshaft.. the X303 is 224 @.050 same centerlines.. only lift is 542 vs the B's 480" cool?? and YES install the X as I suggested installing the B !! cool??

Just me.......................................

Thumper

So I'd be better off using my stock ones with the upgraded springs and stuff I'm getting from you and runnin the B cam?

 

[Chietala]

Sweet article... See whats happens when Lsa, dur, and lift is changed.

http://www.popularhotrodding.com/tech/0607phr_camshaft_basics/lca_selection.html

 

[Flavadave4]

that works for me. i always like learning something new. i just figured it wouldnt make a difference. i know some of the nascar teams are running close to 2:1 rocker arms just because they cant put a big enough camshaft in the block. but they only have to last 500 miles

yeah.....500 miles at 11000 rpm!
thats crazy, and think....they build NHRA motors to last no more than 5 seconds

 

[Chietala]

the bigger the rocker ratio.. the MORE side loading on the valve and valve guide.. esp at the top.. does it mean that the valve train is going to trash its self in a month or two... nope!! it means that there is wear issues and the sideloading also pull HP.. a lot of HP?? Nope... get the idea.?? get the right cam and the right rocker ratio..

Just me.....................................

Thumper

For that reason alone is why roller rockers are so beneficial.

 

[Chietala]

A question often asked is how high a rocker ratio is best. If you consider that the purpose of a valvetrain is to move valves, not pushrods and lifters, then it becomes apparent that the higher the ratio, the better within the mechanical constraints imposed by the materials involved. Current maxed-out valvetrains are lifting the valves to about an inch and running to about 10,000 rpm. All this is being done with rockers in the 1.9 to 2.1:1 range.

Stepping up the rocker ratio is often a good way to increase output with no more than a simple bolt-on mod. Higher-ratio rockers can spread the engine's required LCA. This means that if the existing cam has too wide an LCA, as is so often the case, bolting on a set of high-ratio rockers can pay a handsome dividend. On the other hand, if the LCA was such that the overlap triangle was optimum, installing a higher-ratio set of rockers can drop output rather than increase it. My own tests have indicated, within the ratio range of 1.5 to about 1.9:1, that for every 0.1 ratio increase on the intake, the LCA needs to be spread by 0.75 to 1 degree.

1.72's !!

 

[Chietala]

not really sure...since putting 1.7s on and getting more lift is in essence the same as putting a bigger cam with more lift. maybe im missing something

Theres alot more to it than that. Looks that way but theres more going on in that increase ratio! It also open the valve faster with the higher ratio. The faster the intake is lifted, the less cam duration is required to make peak power.

 

[dragnazz5.0]

yeah i understand that higher ratio rocker arms speed up the valve opening and closing but from my understanding are also less damaging to valve guides. the higher rocker ration has a wider arc than a smaller ratio which helps to keep the tip more centralized on the valve tip and not to pull it. my instructor who was a cylinder head guy for nascar teams for 24 years explained to me that when they went to the higher 1.9:1-2.1:1 rocker ratios valve guide wear almost dissappeared when compared to the lower lift rockers. correct geometry plays a more important roll in valve guide wear and tear than rocker arm ratio does. i also see what your saying about duration but i just dont want people to get confused and think that rockers will change the duration or the LSA of the camshaft. all that stuff cannot be changed without a new camshaft