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post #1 of (permalink) Old 02-15-2000, 07:26 PM
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Recomendations on roller rockers?

I'm having my heads rebuilt on my 88 302. I've called around, and most say that the Ford Motorsport are the best. Of course they are the most expensive at $375 list (289 from Mustangs Inlimited). Crane Cams has some for $230, and Mustangs Unlimited sells some made by Omega Gear I think for $240. These are all 1.7 ratio. Anyone using some? Are you happy with yours? Thanks!

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post #2 of (permalink) Old 02-15-2000, 09:37 PM
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Re: Recomendations on roller rockers?

What do you want out of the engine? How much power and where do you want the power to come in at on the RPM band? What do you plan red line to be? The roller rockers may not be worth it at 1.7:1 ratio. This will hurt torque at the bottom end.

post #3 of (permalink) Old 02-15-2000, 10:15 PM
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Re: Recomendations on roller rockers?

so are you saying that roller rockers have negative effects on bottom-end power? What happens if I were to swap to roller rockers that are the same ratio as the stock ones? are there any benefits?

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post #4 of (permalink) Old 02-16-2000, 07:16 AM
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Re: Recomendations on roller rockers?

My feeling is that any power loss from an additional effective lobe lift/overlap increase will be negated by the power loss from friction, and improper valve engagement. But, then again, that's just my opinion. For you guys out there contemplating a switch to roller tipped rocker arms, Eric is right, what do you want to do?. Is it worth putting a few hundred bucks into something that is really just a complement to additional power gaining techniques? If any of you do decide to go the roller tip method, I suggest checking out Summit Racing, or Jeggs, or any other big name parts distibutor, They have their own brands that they can sell for cheaper prices. For instance, Summit sells a 1.6:1 ratio Ford arm from Comp Cams for about $140, they also have their own brand for about $100, and you would never know the difference between them and the more expensive types.

post #5 of (permalink) Old 02-16-2000, 03:39 PM
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Re: Recomendations on roller rockers?

$100-300 isn't too bad for 15-35 of non emission effecting HP. Add to that the increase in valve guide life and probably some hardly noticable decrease in fuel consumption ......

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post #6 of (permalink) Old 02-16-2000, 08:35 PM
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Re: Recomendations on roller rockers?

Its not the roller rockers themselves lessen the low end power, its the high ratio that does it. Roller rockers are great. I have them in my engine. They minimize wear on the valves and seats and are considerable stronger. I didn't see any increase in performance because of the reduced friction. The higher ratio considerably increases the lift of the cam and now turns a good RV cam into a big loppy race cam that doesn't start working until 3500 RPM and goes to 7000 RPM. Now your cam and intake manifold working ranges are mismatched. The higher lift the new higher ratio creates on the cam is what hurts low end power. Again, roller rockers are good. I wish I could use roller lifters as well, but they require a roller cam and those are too big for the power range I want.

Eric Tachell

post #7 of (permalink) Old 02-17-2000, 03:10 PM
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Re: Recomendations on roller rockers?

Roller lifters don't do much good for a low revving truck engine. You're just as well off with your flat tappet hydraulic lifters. I somewhat agree with you on the rocker arm ratio for a mostly stock engine. The upgrade from a 1.6 to a 1.7 adds an effective overlap in intake and exhaust, as well as raise the effective valve lift, but it wouldn't increase that much. I'm running a 290/300 cam with .472"/.496" lift. This cam is definitely more radical than if someone were to use a stock cam with a greater ratio arm, but...I am also running roughly 10.5:1 compression too, that makes up for the loss of low end torque, but the idle quality is still there. I myself picked this cam for its sound more than anything (just being honest here), but I do mostly city driving now, so the thing really comes on strong around 2000 RPM, not that high up in the rev band to be unusable. I guess it's really rather hard to do a comprehensive discussion on tactics with a limited amount of typing space.

post #8 of (permalink) Old 02-17-2000, 05:11 PM
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I\'m just looking for a little extra power...

My Bronco has enough low-end grunt for my needs right now (no heavy towing). I'd like to have enough power on the highway to not have to downshift out of OD. It runs at around 2000 2500 rpm at 65-70mph. It only does kicks down on hills right now and probably 10 more HP would do it. But I'm also planning on adding 33's or 35's later. I'm going to add headers, a hi flow cat, and single 3" exhaust. I just figured that if the roller rockers were worth it, Id throw them in the heads while I had them off. So everyone seems to think that 1.7 ratio rockers will boost highend power but hurt low end? I appreciate all the advice!

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