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C6 Z06 cam/head recommendations for occassional daily/weekend warrior
C6 Corvette ZR1 & Z06General info about GM’s Corvette Supercar, LS9 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track
C6 Z06 cam/head recommendations for occassional daily/weekend warrior
Hey guys,
I just bought this beautiful, tastefully modded C6Z with about 50k miles, that appears to have been passed around a few times on this forum from previous owners: tjd113, mspell, shlagher. It already has some decent bolt ons (see signature) that I'm looking to exploit during some upcoming events at the local 1/8 mile, Tail of the Dragon, and local autocross, etc. I drive this car to work a few times per month, and want to get into more HPDE as time allows. I figured this thing is pretty much a race car right out of the box, but the deeper I dig into this forum, the more I get scared about oil starvation issues and valve guide wear, etc, etc....
Based on the current mods and mileage, and my plans for the car, would any of you with similar usages or experience recommend "fixing" the heads and adding a high performance camshaft (and what specs), higher capacity oil pump, thermostat, pulley, or anything else while I'm in there?
Or should I leave it as-is and just enjoy the hell out of it??
My main concern is spending a few grand now (that I really don't want to spend) to save myself from $15k+ down the road if the engine decides to grenade itself. I know there is countless info on the web, but I'm having a hard time making heads or tails of it all. The car feels plenty fast and powerful now, but I just don't know if I've drank too much of the forum kool aid on these LS7 issues. Any advice would be appreciated! Thanks!!
Not sure why my signature didn't pop up, but here it is for mod reference:
Kooks longtubes, X pipe, Corsa axle back, CES mufflers, Halltech killer bee intake, Fast 102 intake, throttle body, and fuel rails, B&m short shifter, Katech valve covers, 20x12, 19x10 Cup wheels, Colman 2 piece front rotors, Pfadt racing coil overs, Pfadt racing sway bars, Zr1 splitter, Rocker panels w mud flaps, Breathless performance rear diffuser, Rear spoiler, LED taillights, 3000k HID fog lights, DS leather interior with carbon fiber door and console inlays...
Addressing the heads is a must. I went with Tony Mayo's Trick Flow heads and love them. Depending on budget, either get your heads worked over or buy new aftermarket. A bump in compression and porting would be a nice upgrade while you have the heads off. Have a cam spec'd to match heads.
stock oil pump is plenty, I did a Katech 501 cam with a head fix (guides and new exhaust valves) on a buddies C6Z. He loves it and ran a 10.7 with almost no seat time. Very streetable too.
347-2110 - Johnson Lifters Drop-In Hydraulic-Roller, No Link Bar, .045" Taller Than LS7 Lifter, .035" Recommended Pre-Load +-.010"
6 Kit 28-HCBasic - Basic Heads & Camshaft Bolt & Gasket Kit
28-12582179 - SINGLE GM LS7 Cylinder Head Gasket
25-TSPHB0568 - TSP Gen IV Cylinder Head Bolt Kit, PER CYLINDER HEAD!
28-11570163 - GM Dry Sump Harmonic Balancer Bolt; LS7, LS9 & Dry Sump LT1/LT4
25-TCG - TSP LS Timing Cover Gasket, Like 12633904
25-FCS - TSP LS Front Crank Seal, Like 12585673 202-C5174 - Cometic LSx Water Pump Gasket Set, Includes Two Gaskets
80-L310015204 - LPE 160 Degree Thermostat GM
I forgot to order the CHE trunion upgrade and ARP head bolts so I'm going to call back and get those as well.
I don't see too many reviews on this cam, but it came highly recommended from TSP for my needs, so I hope it works! It will be cool to have something different, so fingers crossed for reliability!
Let me know if you have any thoughts, recommendations, or dyno guesses when she's all wrapped up!!
7.800 is going to be way too long. The johnson 2110 seats are approx 0.045" higher than stock LS7 lifters.
As reference I am running 7.650" pushrods with ls7 stock base circle cam, heads shaved 0.030" and 2110's. This gives me around 0.035" average preload on the lifters.
7.800 is going to be way too long. The johnson 2110 seats are approx 0.045" higher than stock LS7 lifters.
As reference I am running 7.650" pushrods with ls7 stock base circle cam, heads shaved 0.030" and 2110's. This gives me around 0.035" average preload on the lifters.
Exactly! You're going to need shorter PR's and I'd tell TSP to just keep theirs, (because I don't think they normally stock the length that you need.)
I went with a custom grind TSP cam with Johnson 2110's as well, and my heads from AHP just shipped last week, so while I haven't got it all together just yet, I've been putting together my build for months now. I calculated 7.650" PR's to start with, as well, but you're going to always want to measure to be certain. And I only went with a minimal resurfacing of the heads; the more you shave off theoretically the shorter your PR length will be.
This is what I learned from Kohle at AHP. 7.800" are the OE PR length for the OE LS7 lifters, which have about .120" of preload. AHP typically reinstalls on their LS7 builds 7.775" PR's to slightly reduce this preload and to compensate for for the valve job; put's the preload to about .100". (I believe both the OE LS7 lifter and the Johnson 2110's have a similar amount of lifter plunger travel, the Johson 2110's are .201")
So first off you need to account for the difference in height of the two lifters, (.048"), and then you need to account for the difference in preload that you are aiming for with the Johnson 2110's, which is .035" +/- .010". So if you take that .100 preload (based on a 7.775" PR,) and subtract from it the 2110 preload of .035", you get a figure of .065". Now go back to the top figure with those 7.775" PR's and .100 preload, subtract for the difference in lifter heights (.048") and then subtract this new difference in preload (.065"), you get 7.662". Your two closest PR lengths will be 7.650" and 7.675" and that is where I decided to start with the 7.650" PR's.
Also, as long as you're going to swap cams, you're going to need a custom tune and a 160° thermostat is pointless with your new tune, IMO. And I don't know of anybody who hasn't recommended ARP head bolts and crank bolt, (get a good torque wrench.)
Another thing you may want to consider is the harmonic balancer since you'll have yours off, anyways. While not as prevalent on the LS7 as it was on the other LS engines, the OE HB's are prone to premature failure and on a Corvette with little room, they're a PITA to swap.
Since there is a much better option available from PowerBond without having to go full exotic and pay those associated hefty prices, take a look into the PowerBond Race Performance series LS7 HB, PB1503SS. Forged 1045 steel, SFI 18.1 rated, dynamically balanced, unique rubber and bonding process, clear coated finish and laser etching serial number, 10X the push strength of an OE HB, rated up to 9,500 rpm.
The two parts side by side just don't compare, the PB race series HB is a work of art compared to the OE HB. AutoZone actually carries them and you can often use a 20% online ship-to-home coupon with free shipping. Pre-tax I got mine from them for $254 and it dropped shipped from Dayco in Memphis, (parent company of PowerBond, who has otherwise only been making top quality HB's in Australia for over 40 years.) Sure, you can spend more on ATI and others, but do a search on ATI's LS7 HB's on this forum before you drop $400+ on one of those.
Also, while I'm otherwise going to have off the OE timing chain, with all that I have invested into this build, I decided to go with a genuine Katech C5-R timing chain, (HME-G68V-2). Just one more of those variables to eliminate while your in there.
Last edited by BigVette427; 09-19-2017 at 07:10 PM.
I will certainly look into those options and report back with where we end up
Heads up on the pushrod lengths for the Johnson 2110's. I took my Z06 and new heads/cam over to my builder last week and he just got it back up and running yesterday. He calculated .039" preload with 7.775" PR's. When I spoke to the Johnson product manager last week he pointed out that the 2110 "ball cup seat height" is what is .048" taller than the LS7 lifter, (implying perhaps that the overall lifter is not actually any taller than an OE LS7 lifter.)
Of course, you always have to measure your actual PR length for your specific application as there are multiple variables that affect that length and best practice will always be to measure. I only did a minimal amount of resurfacing on the heads, used GM MLS head gaskets, and I installed a new TSP custom grind cam off an 8620 core.
TSP even says on their website that the 2110's are ".045" taller than an LS7 lifter", but I think there may be some confusion with how Johnson talks about the "ball cup seat height." Considering the difference in preload with the GM LS7 lifters versus what the Johnson's call for at .035" +/- .010", I was a little nervous when I initially heard 7.775" but the car ran super quiet under the hood and my builder knows what he's doing. (Johnson says the 2110's have a .201 plunger travel, so it's not like these are the short travel lifters.) This would make some sense since Johnson advertises these 2110's as "drop-in" lifters for LS motors, so it would only be logical that they were designed with the same dimensions as the LS7 lifter, (which has essentially become the standard (non-DOD) lifter for the LS motors.)
Last edited by BigVette427; 10-11-2017 at 10:32 AM.
Heads up on the pushrod lengths for the Johnson 2110's. I took my Z06 and new heads/cam over to my builder last week and he just got it back up and running yesterday. He calculated .039" preload with 7.775" PR's. When I spoke to the Johnson product manager last week he pointed out that the 2110 "ball cup seat height" is what is .048" taller than the LS7 lifter, (implying perhaps that the overall lifter is not actually any taller than an OE LS7 lifter.)
Of course, you always have to measure your actual PR length for your specific application as there are multiple variables that affect that length and best practice will always be to measure. I only did a minimal amount of resurfacing on the heads, used GM MLS head gaskets, and I installed a new TSP custom grind cam off an 8620 core.
TSP even says on their website that the 2110's are ".045" taller than an LS7 lifter", but I think there may be some confusion with how Johnson talks about the "ball cup seat height." Considering the difference in preload with the GM LS7 lifters versus what the Johnson's call for at .035" +/- .010", I was a little nervous when I initially heard 7.775" but the car ran super quiet under the hood and my builder knows what he's doing. (Johnson says the 2110's have a .201 plunger travel, so it's not like these are the short travel lifters.) This would make some sense since Johnson advertises these 2110's as "drop-in" lifters for LS motors, so it would only be logical that they were designed with the same dimensions as the LS7 lifter, (which has essentially become the standard (non-DOD) lifter for the LS motors.)
Thanks for the feedback!
I admit the math wasn't adding up for me, since I'm having the heads milled .035" and going with the Johnson lifters and OEM head gaskets, so the 7.800" (OEM length) pushrods did seem to be too long. Now I don't know what the difference in the cam base circle is on my TSP Stage 2.2 vs the stock cam, but my builder is going to measure the pushrod length to be sure. TSP said the 7.800" length works 95% of the time in these setups. I hope to have the heads back next week, so we will see...
Part of what sold me on the Johnson 2110's was the solid reviews of a lot of guys using them on their LSA's over on a CTSV forum. I found this comment from what I perceive (based on numerous threads/posts and even direct email,) to be a knowledgeable guy, interesting. Says you can setup the 2110's the same as GM LS7 lifters.
Still want to measure, of course. Let us know what you find out on your build.
Sure it can but will add 0.045" to your preload compared to stock.
Technically as long as it is within the 0.200" travel it wont destroy itself. It is just reccomended to take advantage of its slow leakdown and tight tolerances by running really low preload.
Sure it can but will add 0.045" to your preload compared to stock.
Technically as long as it is within the 0.200" travel it wont destroy itself. It is just reccomended to take advantage of its slow leakdown and tight tolerances by running really low preload.
I don't quite understand it either but all I know is he put one of my 7.650" PR's in (opened the sealed package so hopefully I can still return them) and said it was "way too (F'in) short." He used his PR checker and verified the length with a dial caliper and started with 7.800" and said that put him at too much preload. He then tried his PR checker at 7.775" and said that gave him .039" of preload which was right what we we're shooting for.
Last edited by BigVette427; 10-12-2017 at 08:57 AM.
Do you know if your builders used checker valve springs and/or pressurized the lifters before measuring pushrod length? I'm not an expert on this, but just want to make sure my builder measures them the right way
Do you know if your builders used checker valve springs and/or pressurized the lifters before measuring pushrod length? I'm not an expert on this, but just want to make sure my builder measures them the right way
Tony Mamo educated me on the process of measuring. I'll try and explain the process as clearly as he did for me.
He told me to set the adjustable pushrods to approximate length. Set the cylinder to be checked at TDC. Insert the adjustable pushrods into the lifter bores. Then put the rockers on and tighten rocker bolts hand tight. Now check for lash between the adjustable pushrods and the rocker arms. If there is lash then remove the rocker, and extend the adjustable pushrod. Repeat this process until there is just the absolute faintest amount of lash between the rocker and adjustable pushrod. At this point if you tighten the rocker bolt with a wrench you should now have zero lash. If you have zero lash after snugging the rocker bolt with a wrench, but still have a very small amount of lash when the rocker bolt is tightened by hand, then you have properly completed the pushrod length setup. Finally you add your preload amount to the adjustable pushrod measurement you just adjusted for, and you have the correct pushrod length.
09-12-2017, 05:05 PM
C6 Z06 cam/head recommendations for occassional daily/weekend warrior
