bigger valves yea or nay
Thread Starter
Burning Brakes
Joined: May 1999
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From: waller texas
Cruise-In I Veteran
bigger valves yea or nay
I am rebulding my L98 and wonder would going to 2.02/1.6 valves cause more problems than they would positive gains? Would The bigger valves need bigger t/b and would they make using my stock ecm a nightmare?
I am only going to use the powermax 2032 crane cam so maybe there is no need to go the bigger valves. This cam has 452/465 lift, 214/220 duration @ .50, 270/276 adv duration. Supposedly this is biggest cam I can run and still pass emissions and be ecm compatible.
Also what is the verdict on using a good used low mileage cam at half price of new cam?
I sure don't know squat when it comes to matching components for max hp.
I am only going to use the powermax 2032 crane cam so maybe there is no need to go the bigger valves. This cam has 452/465 lift, 214/220 duration @ .50, 270/276 adv duration. Supposedly this is biggest cam I can run and still pass emissions and be ecm compatible.
Also what is the verdict on using a good used low mileage cam at half price of new cam?
I sure don't know squat when it comes to matching components for max hp.
Race Director
Joined: Feb 2004
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Re: bigger valves yea or nay (vert2go89)
I would not use the larger valves. The expense probably wont justify the cost. 2.00 and 1.56 are the largest valves you can fit on a 113 casting seat. I would use a roller cam (used) in a heartbeat. I would never use a flat tappet cam that was used.
Race Director
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Re: bigger valves yea or nay (Pete K)
My previous post was basted on an assumption that your stock valves were perfectly fine for reuse. No excessive wear . If this is not the case and new valves are nescessary I would consider 2.00 and 1.56.
Thread Starter
Burning Brakes
Joined: May 1999
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From: waller texas
Cruise-In I Veteran
Re: bigger valves yea or nay (Pete K)
I have the heads in now getting checked. Also can my injectors be tested to see if they can be used again when I go back together with engine? The engine had 127,000 miles on it and I don't know if are original. From what I have seen the L98 used 22# injectors, if they are bad should I go to 24# injectors? Wher can I get the best price on new ones?
Race Director
Joined: Feb 2004
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Re: bigger valves yea or nay (vert2go89)
Checking heads are cut and dry for a machine shop. They will mic valves, guides etc. 24# will be fine. I have been using Ford Motorsports for 12 years and 120k with no problems. They seem to be the injector of choice for almost everyone. They are priced right at about $220
Race Director
Joined: Feb 2004
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Re: bigger valves yea or nay (vert2go89)
Summit and Jegs carry them. Many others also. They have gotten so cheap that it almost dosent make sense to test, clean and balance. If I were searching for every last hp I would send them out to be balanced. For me and most people a new set out of the box is perfect.
Team Owner
Joined: Dec 2000
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From: SE NY
Cruise-In II Veteran
Re: bigger valves yea or nay (vert2go89)
Bigger valves will work best with a little chamber work to unshroud the intake valve.
Indeed 2.00/1.56 valves are the largest to fit your stock seats but larger seats can be installed and then 2.02/1.60 valves will fit fine. But here you surely want some unshrouding work done to the heads.
In any case, since the heads are off, you will gain about 25-30chp from pocket porting and changer unshrouding. Also, install a set of 1.6:1 ProMagnum RRs.
The main issue with emissions is in valve timng overlap, not with lift. What is the LSA of that cam (from the shown specs it doesn't look like there will be any emisions issues)?
Indeed 2.00/1.56 valves are the largest to fit your stock seats but larger seats can be installed and then 2.02/1.60 valves will fit fine. But here you surely want some unshrouding work done to the heads.
In any case, since the heads are off, you will gain about 25-30chp from pocket porting and changer unshrouding. Also, install a set of 1.6:1 ProMagnum RRs.
The main issue with emissions is in valve timng overlap, not with lift. What is the LSA of that cam (from the shown specs it doesn't look like there will be any emisions issues)?
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Race Director
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Re: bigger valves yea or nay (65Z01)
I wouldn't bother with anything above 2.00/1.56 valves on a 350 engine. The valve is too big and essentially "gets in the way" You can gain a little bit of high lift flow with larger valves which may well come at a significant cost in mid lift flow. This can actually cost you horsepower, which isn't a good thing, especially considering you have to pay more to get the 2.02's to fit in the first place.
[Modified by Nathan Plemons, 9:34 PM 4/28/2004]
[Modified by Nathan Plemons, 9:34 PM 4/28/2004]
Pro
Joined: Dec 2002
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From: salem or
Re: bigger valves yea or nay (Pete K)
Yeah, I'd go with the larger valves (2.02)...but not too big (like 2.08 or 2.10 unless you've got a bigger bore 4.125 vs. 4.00.)
Even if you use the stock (small) valve seats, you can still get some extra ponies by grinding a larger, smoother radius on the valves seat to accomidate the larger valve face.
Talk to your machine shop. sj
Even if you use the stock (small) valve seats, you can still get some extra ponies by grinding a larger, smoother radius on the valves seat to accomidate the larger valve face.
Talk to your machine shop. sj
Burning Brakes
Joined: May 2000
Posts: 1,160
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From: Nashville TN
Re: bigger valves yea or nay (speedjohnson)
I'd vote for 2.0 and 1.56 Ferrera Valves. They flow great and are available cheap at http://www.sdpc2000.com Their internet site does not show all the valves they carry, but call or e-mail them and they can get them in any size you want. Over that, you'll need new valve seats and the gains per dollar won't be there. I think I paid around $11 a valve for the Ferrera's.