Boosting engine power. Rollerizing?

[dodge68charger]

I looking to gain some more power from my big block engine. It has the factory cast iron heads. Will putting a roller valve train, cam, lifters, rockers make a huge difference power wise with the stock heads? Will it be noticeable?

 

[Propwash]

Roller valvetrain typically has a lot taller and quicker ramps. To say the least i'd imagine you'd be changing springs to accommodate. That being said if you really want to make "Huge" power, just upgrading to a roller cam & rockers is kinda putting the cart in front of the horse. If you really want to make some serious power you'll need to either really open up them iron heads with some decent porting or upgrade up to some better flowing aluminum heads. You can use that cam to open up the valves further and play with the open/close duration, but in the end you'll still be limited by the amount of CFM those heads will flow.

Don't get me wrong, you can still make some decent power, but if you really want some "feel it in the seat of the pants" huge difference, you should start with the heads and build your cam & valvetrain from there.

Good luck

 

[lewtot184]

i wouldn't spend that kind of money with stock heads.

 

[Cranky]

I ran a roller cam that was .660 lift back in the 80's and was turning 7300 with it through the traps using Isky non roller rockers. After over 300 passes, the guides were in pretty good shape. Roller rockers do very little with the smaller cams and once you get pretty big, then a roller rocker will help prevent excessive valve guide wear and might show a bit of a horsepower gain vs non roller rockers. Imo, using a roller rocker with mild cams is a waste of money but using a roller cam does help even with a mild hydraulic street setup. Now is it worth the money vs hp increase? To me, using a mild roller cam is worth not having to mess with cam break in and worrying about zinc rich oils. Also, years ago I saw some dyno tests using roller rockers vs non roller on a mild cam and the numbers didn't really move enough to even know if they made any difference or not.

 

[Meep-Meep]

You can get a boost in power a hell of a lot cheaper than what you would spend on a roller valve train. A simple hemi grind hydraulic, headers and a good intake will make a huge difference for a lot less money. But to address your question on a different level, it's most likely the cam profile that will make the power boost not just the fact that it's a roller.

 

[Cranky]

You can get a boost in power a hell of a lot cheaper than what you would spend on a roller valve train. A simple hemi grind hydraulic, headers and a good intake will make a huge difference for a lot less money. But to address your question on a different level, it's most likely the cam profile that will make the power boost not just the fact that it's a roller.

Generally, two cams of the same profile but one being a roller will free up a big of horsepower....but like I mentioned, I like the fact that break in isn't an issue with a roller....

 

[bigmanjbmopar]

:happy1:

 

[Cranky]

Got sum butta for dat pcorn.....

 

[Meep-Meep]

Generally, two cams of the same profile but one being a roller will free up a big of horsepower....but like I mentioned, I like the fact that break in isn't an issue with a roller....

Sure, but my main point was that rollers tend to be more aggressive than flat tappets, which is likely the biggest gain. But yes, I'd agree anything that reduces friction is a boost.

 

[shag766]

Roller valvetrain typically has a lot taller and quicker ramps. To say the least i'd imagine you'd be changing springs to accommodate. That being said if you really want to make "Huge" power, just upgrading to a roller cam & rockers is kinda putting the cart in front of the horse. If you really want to make some serious power you'll need to either really open up them iron heads with some decent porting or upgrade up to some better flowing aluminum heads. You can use that cam to open up the valves further and play with the open/close duration, but in the end you'll still be limited by the amount of CFM those heads will flow.

Don't get me wrong, you can still make some decent power, but if you really want some "feel it in the seat of the pants" huge difference, you should start with the heads and build your cam & valvetrain from there.

Good luck

X2 with the heads

 

[dodge68charger]

Thanks guys. Appreciate the help. I guess im gonna invest in aluminum heads first. The amount the valvetrain parts are gonna cost me compared to new heads for the power i want isnt worth it. Was just hoping rollerising the engine would generate tons more power but i wanna dtuff as much air in those cylinders as possible. Thanks guys

 

[Dako]

You can get a boost in power a hell of a lot cheaper than what you would spend on a roller valve train. A simple hemi grind hydraulic, headers and a good intake will make a huge difference for a lot less money. But to address your question on a different level, it's most likely the cam profile that will make the power boost not just the fact that it's a roller.

What is a 'Hemi grind'? Seriously, I have not heard of that term. Thanks in advance.

 

[Meep-Meep]

What is a 'Hemi grind'? Seriously, I have not heard of that term. Thanks in advance.

It's an old Direct Connection Purple Shaft cam that's been around since the 70's or possibly earlier but ground for the wedge engines both SB and BB. Great street cam if you want to do a basic garage build. .474" / 280 on a 110 LCA. The older version (early 80's and back) had 284 duration.

 

[bigmanjbmopar]

It's an old Direct Connection Purple Shaft cam that's been around since the 70's or possibly earlier but ground for the wedge engines both SB and BB. Great street cam if you want to do a basic garage build. .474" / 280 on a 110 LCA. The older version (early 80's and back) had 284 duration.

The Professor :headbang:

 

[Meep-Meep]

Here's an ebay link for an old DC Hemi grind cam for the small block
http://www.ebay.com/itm/Cuda-318-34...Parts_Accessories&hash=item234a13d43e&vxp=mtr

Summit still has it available but doesn't call it a hemi grind. Redesigned big block version as was available from the mid 80's -
http://www.summitracing.com/parts/dcc-4452993ae/overview/make/plymouth

 

[383man]

I agree that just going roller cams and rockers wont be a big power gain. Ron