roller rockers
Instructor
Joined: Sep 2006
Posts: 233
Likes: 1
[QUOTE=TTRotary;1558850743]Shawn, I am not going to argue with you to prove a point. After very careful consideration, discussion with several vendors, and price comparisons, I chose the roller rocker route. I am very happy with it and I still believe it was the best choice for me. Incidentally, I am making 427RWHP without touching the heads or the cam.
QUOTE]
Is there a link to a post that summarizes your mods?
QUOTE]
Is there a link to a post that summarizes your mods?
Race Director
Joined: Jan 2000
Posts: 12,375
Likes: 406
From: Florida
Not sure, but here they are:
Kooks LT headers with cats, stock mufflers, hand ported TB, ported FAST, Vortex Rammer, the rockers, Patriot Dual Gold springs, Manley hardened pushrods, Ti retainers, and of course a tune.
Car did 355 RWHP bone stock, 427 with all the mods and tune, and is back down to 400 after putting on 4.10 gears. The gears were not broken in for the pull, hence the significant power loss. Car goes back to tuner for LT trims in a few weeks, and I expect it to be 10 stronger.
Kooks LT headers with cats, stock mufflers, hand ported TB, ported FAST, Vortex Rammer, the rockers, Patriot Dual Gold springs, Manley hardened pushrods, Ti retainers, and of course a tune.
Car did 355 RWHP bone stock, 427 with all the mods and tune, and is back down to 400 after putting on 4.10 gears. The gears were not broken in for the pull, hence the significant power loss. Car goes back to tuner for LT trims in a few weeks, and I expect it to be 10 stronger.
Thread Starter
Melting Slicks
Joined: Jun 2006
Posts: 2,690
Likes: 1
From: Northern Calif
Not to bust you hump but any graphs to check out of your 425 pull? not that I dont believe you, I just want to see the low end response. Or is there a link you can direct me to. Who did the work? Approx cost of all mods without the 410s?
Race Director
Joined: Jan 2000
Posts: 12,375
Likes: 406
From: Florida
if you're happy with your gains and it has been a trouble free mod, no argument here. 427rwhp without a cam is very nice. if you want to read more of the opposing views, go here
http://forums.corvetteforum.com/show....php?t=1615200
http://forums.corvetteforum.com/show....php?t=1615200
I think 5 things emerge clearly from all the posts on this topic:
1. Go with a tried and true setup, like the Crane variables, the HS, or the Comps.
2. Avoid the SLP kit.
3. Do not try to cut corners with the ancillary, but critical items: springs, rods, Ti retainers. Same applies to cam swaps. You will spend the money sonner or later anyway.
4. Have an experienced installer do this and set adjustments, and ALWAYS go with a reputable vendor, even if they cost more.
5. There is a lot of misinformation and lack of knowledge on this topic.
FYI, my Comps went in without clearance issues, and they are Shaft Mount rockers.
Thread Starter
Melting Slicks
Joined: Jun 2006
Posts: 2,690
Likes: 1
From: Northern Calif
lets see 427-355= 72 hp change. Say 10% fudge factor for dyno on different day = 65hp
say 25 from headers
say 10 from intake and TB
say 25 from RRockers
tune 5hp
sounds logical and without tearing deep into car and probably darn reliable too. (Forget $/hp)
What about torque #s?
say 25 from headers
say 10 from intake and TB
say 25 from RRockers
tune 5hp
sounds logical and without tearing deep into car and probably darn reliable too. (Forget $/hp)
What about torque #s?
Race Director
Joined: Jan 2000
Posts: 12,375
Likes: 406
From: Florida
525 or 522, IIRC.
I took pictures of the dyno charts and can email you a jpeg when I return home. I did not post the pictures because I am fed up with the effort involved to get pictures on the forum, especially my efforts to document the FAST porting which were for naught.
I can tell you that the "after' dyno overlays the stocker exactly, +5HP, until about 3200, and that is where it progressively separates itself from the stock pull. That applies to both torque and HP. I have kept the stock rev limit, for now.
Orange County Corvettes did the work. Big
to them. I'd rather not talk about price, but here goes: shaft rockers+springs+ rods+retainers+install: about 1500. Got the Kooks for 1350+500 install. The Vortex was a nightmare because the damn thing doesn't fit. Avoid that intake. FAST I got for $750, and I spent 5 hours porting it, plus OCC spent anoth 3 getting it on. Sean spent 3 hrs on the TB.
And don't ignore the 4.10s. If you can't afford motor mods + gears, then do gears and spend the money on an extra wheelset with Nitto R2 tires to handle the grip. Hands down the single best mod you can do. Gears are $2K installed.
Speed costs money.
I took pictures of the dyno charts and can email you a jpeg when I return home. I did not post the pictures because I am fed up with the effort involved to get pictures on the forum, especially my efforts to document the FAST porting which were for naught.
I can tell you that the "after' dyno overlays the stocker exactly, +5HP, until about 3200, and that is where it progressively separates itself from the stock pull. That applies to both torque and HP. I have kept the stock rev limit, for now.
Orange County Corvettes did the work. Big
to them. I'd rather not talk about price, but here goes: shaft rockers+springs+ rods+retainers+install: about 1500. Got the Kooks for 1350+500 install. The Vortex was a nightmare because the damn thing doesn't fit. Avoid that intake. FAST I got for $750, and I spent 5 hours porting it, plus OCC spent anoth 3 getting it on. Sean spent 3 hrs on the TB. And don't ignore the 4.10s. If you can't afford motor mods + gears, then do gears and spend the money on an extra wheelset with Nitto R2 tires to handle the grip. Hands down the single best mod you can do. Gears are $2K installed.
Speed costs money.
Race Director
Joined: Jan 2000
Posts: 12,375
Likes: 406
From: Florida
lets see 427-355= 72 hp change. Say 10% fudge factor for dyno on different day = 65hp
say 25 from headers
say 10 from intake and TB
say 25 from RRockers
tune 5hp
sounds logical and without tearing deep into car and probably darn reliable too. (Forget $/hp)
What about torque #s?
say 25 from headers
say 10 from intake and TB
say 25 from RRockers
tune 5hp
sounds logical and without tearing deep into car and probably darn reliable too. (Forget $/hp)
What about torque #s?
You can't really break it down like that, because the mods all work together. Change the mods and all the relationships change. For instance, the car was at 400 with mods but before tune. Does that mean if Sean tunes a bone stock car he will add 25 HP? Of course not.
What I can say is that other customers at OCC who did the same mods, but did not port the FAST and used SLP rockers, got 398-403. I think the porting work done on the FAST and the TB made a big difference. One thing is for sure: every little bit helps and it adds up.
Torque was about #5 shy of the HP #. Remember the rev limit was not raised, so additional HP cannot happen without torque gains.
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Race Director
Joined: Apr 2005
Posts: 10,436
Likes: 4
From: Everett Wa
TT thanks for the breakdown. This is just what I am looking for, 400rwhp without breaking into the motor. Now to just find a shop that can do the work. Or I may do it myself. Only thing I may add is a cooler t-stat.
TT by the way did you go with the 1.7 or 1.8?
TT by the way did you go with the 1.7 or 1.8?
Last edited by TMyers; Feb 8, 2007 at 08:49 PM.
Race Director
Joined: Jan 2000
Posts: 12,375
Likes: 406
From: Florida
TMyers: mine are 1.85 rollers. 1.7 is stock. Another route is the Crane variable rollers like SpinMonster used, which come off the seat much faster so that they behave almost like a 1.8 initially. This is the same concept as an XER-grind cam where the ramp is steeper.
Knkali - I understand.
Knkali - I understand.
Race Director
Joined: Jan 2000
Posts: 12,375
Likes: 406
From: Florida
Hard to say without graphing the opening curve and comparing the area underneath. I'm going to say the 1.8 Crane variables, if I have to bet. I did the Comps because the installer had experience with them, but had never put the Cranes in a car. Plus the Comps were shaft rockers (paired rocker sets) which is supposedly a more rigid (better) setup.
Melting Slicks
Joined: Jul 2004
Posts: 3,092
Likes: 120
From: orlando florida
St. Jude Donor '15
Melting Slicks
Joined: Jul 2004
Posts: 3,092
Likes: 120
From: orlando florida
St. Jude Donor '15
made it better. one thing with an auto car with a stock converter. up until about 3000 rpms, it feels sluggish. right at 3000 rpms, the motor starts picking up. the rockers brought this down to around 2500 rpms.
here's my timeslips also.
before rockers
after rockers
