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429 sbc ls build

General engine tech -- Drag Racing to Circle Track

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slo-svt
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429 sbc ls build

Post by slo-svt » Mon Nov 05, 2018 2:41 pm

As some may remember I made a post a while back about ls7 head sealing issue. The thread ended with me finding i had cracked a sleeve. I am starting to get some parts so I figured i would get everyone's input. Here is a rundown of what i have/ plan to use.

Parts i have include
Ls7 aluminum block with darton hd sleeves.
Mahle -3cc flat top pistons pn 930221530
Factory Crankshaft and Titanium Connecting rods.
I have 2 sets of factory ls7 heads (one stock and they other hand ported w/ 50 degree seats and milled .085 (58cc chamber)) i would like to port the factory set and do a similar valve job to swap and see how much power compression is actually worth.
I am thinking of using factory lifters with travel limited using shims
I still have 2 cams that ran in the engine prior to it breaking 250/262@.050 112 lsa 108 icl .360 lobe lift and 240/258 @.050 114lsa 109icl .362 lobe lift
I have 3 intake manifolds msd atomic, holley sniper, stock

Parts i still have to get
adjustable t and d rockers (pn 15015)
Another cam (I'm thinking 25x,26x @ .050 with .420-.440 lobe lift)
Manley dual springs pn 221421-16 (i will be using stock titanium intake valves and hollow stem exh valves)
Arp Rod Bolts
I may end up getting a CID intake manifold but haven't decided yet (will be difficult to run with factory computer but may try something to make it work)

I would love to hear suggestions from people that have ran .400 plus lobe lift with a hydraulic roller lifter on what lobe series you like/dislike. Then only thing i see in comps catalog i see for hydraulic is the DTL series. Some people have run solid roller lobes but honestly i don't have a ton of experience with different lobe profiles. Let me know what your thoughts concerns are. What you would like to see. I plan to put this on an engine dyno hopefully in January to do the testing.
"I believe in the scientific method and one should have a healthy skepticism of things in general. From a scientific standpoint, you always look at thing probabilistically and not definitively."

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Re: 429 sbc ls build

Post by CGT » Mon Nov 05, 2018 4:08 pm

If your springing for the T&D shafts, expensive small diameter dual springs...then your only one component away from running a solid roller cam. At those lobe lifts with the 1.8 ratio, I would almost have to be bound by rules to run a hydraulic roller. Not to mention their is not a a lot available in hydraulic roller lobes with .400+lobe lifts. And I'm not sure I would want to "hybridize" solid roller lobes with hydraulic lifters on them for a street car unless I had to.

Your valvetrain is very light, and well designed. I would think a solid roller could be run without going too crazy on spring pressures. Chris Padgett would have been a good one to talk to at Comp,(he may be on tour) but he is at Crane now. If you can deal with potential southern sarcasm , give Bullet a call they will either piss you off or help you.

Shoot RW TECH a PM, he has been around the block with some LS valvetrain stuff. It'd be interesting to see how he feels about it. He has posted and pm'd me some interesting valvetrain related LS stuff he was involved with.
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Re: 429 sbc ls build

Post by Newold1 » Mon Nov 05, 2018 4:50 pm

I think a few of us would like to hear from you what you intend for use on this engine. The vehicle going into and it's specs., Approximate HP @ rpm, torque @ rpm and Top rpms. So much of what you will need to consider for your build will come from your intended use. Without a lot of detail this conversation is a bit like horseshoes and handgrenades. Close, but not close enough.
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slo-svt
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Re: 429 sbc ls build

Post by slo-svt » Mon Nov 05, 2018 6:33 pm

Newold1 wrote:
Mon Nov 05, 2018 4:50 pm
I think a few of us would like to hear from you what you intend for use on this engine. The vehicle going into and it's specs., Approximate HP @ rpm, torque @ rpm and Top rpms. So much of what you will need to consider for your build will come from your intended use. Without a lot of detail this conversation is a bit like horseshoes and handgrenades. Close, but not close enough.
The engine is going in my 2008 z06. Just a street/strip car. It will run on e85 primarily. Max rpm is probably going to be around 8000. I would like see peak power somewhere around 7200 and peak torque at 56-5800. My goal is 770-780hp and 610ft/lbs.
"I believe in the scientific method and one should have a healthy skepticism of things in general. From a scientific standpoint, you always look at thing probabilistically and not definitively."

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Re: 429 sbc ls build

Post by cv67 » Mon Nov 05, 2018 7:55 pm

8k, run a solid roller..less to go wrong
And I'm not sure I would want to "hybridize" solid roller lobes with hydraulic lifters on them for a street car unless I had to.
not sure why guys insist on doing it either, noones unlocking secrets of the universe. Do one or the other

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Re: 429 sbc ls build

Post by slo-svt » Mon Nov 05, 2018 11:09 pm

CGT wrote:
Mon Nov 05, 2018 4:08 pm
Your valvetrain is very light, and well designed. I would think a solid roller could be run without going too crazy on spring pressures. Chris Padgett would have been a good one to talk to at Comp,(he may be on tour) but he is at Crane now. If you can deal with potential southern sarcasm , give Bullet a call they will either piss you off or help you.
cuisinartvette wrote:
Mon Nov 05, 2018 7:55 pm
8k, run a solid roller..less to go wrong
And I'm not sure I would want to "hybridize" solid roller lobes with hydraulic lifters on them for a street car unless I had to.
not sure why guys insist on doing it either, noones unlocking secrets of the universe. Do one or the other
I think the hydraulic cam is the way to go on my engine for several reasons.
1. I drive the car everywhere (It is not trailered unless it broken. Its 60 miles one way to nearest race track from my house) and the hydraulic lifter will require less maintenance, quieter, easier on parts, less spring pressure.
2. Modern day hydraulic lobes are just a mean as a solid roller lobe and with adjustable valvetrain I will have the ability to move lifter preload as I see fit.
3. The stock lifters have already went 7500 in this engine many times with stock rocker arms, less spring pressure, stock lifters. The stock lifters are nice pieces. I'm not concerned with their ability to go 8000.
"I believe in the scientific method and one should have a healthy skepticism of things in general. From a scientific standpoint, you always look at thing probabilistically and not definitively."

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Re: 429 sbc ls build

Post by Rowdy Yates » Tue Nov 06, 2018 5:29 am

.400+ lobe lift on any stock lifter is no good ....think you may have meant stock style lifter. With that said if you've got the adjustable rocker arms may as well run the solid roller + on HP most adjustments are after peak runs not typical daily use. Friend Darth has a similar engine 428 Ls7 with LLSR and sniper intake. Lifters and springs either way you go are needed for over .700 lift using a .400 + lobe hydraulic or solid roller. Go solid roller. Lots of daily driver S/R cams being used....

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Re: 429 sbc ls build

Post by Newold1 » Tue Nov 06, 2018 9:21 am

I think you may be 75-100HP shy of your power goal with your combination in a low hood profile Corvette and a regular street driven car in a N/A engine format.

It will take a long duration high lift camshaft to get the engine producing those kinds of power with some pretty big flowing heads and a LOT of Compression! It would need something like a well setup Holley HIRam intake. Factory vette cams can operate at 7000rpms easily because they don't have the larger spring pressures a camshaft that would be needed to feed this level of power and higher rpms it will take to get there.

I don't believe there is a hydraulic roller that can do this for you even with the best valve train design.

If you want to see the LSX that can get there you need to take a look at the Camaro LSX COPO engines and you will probably realize why they would be a difficult BITCH to drive dailey on the street.

I am not trying to pupu your project but I think based on street driving acceptable manners and the restrictions of a low hood clearance and cooling issues on a ZO6 Corvette you may want to look at lessen your expectations for power level and driveability and plan your build around a workable solution
-OR slap a supercharger on the engine like GM did! JMO
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Re: 429 sbc ls build

Post by pdq67 » Tue Nov 06, 2018 9:47 am

Get a, "STREET SOLID ROLLER", cam and don't look back.

BBC, CC's great old 288AR is a dandy street solid roller cam so spec yours accordingly.

pdq67

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Re: 429 sbc ls build

Post by slo-svt » Tue Nov 06, 2018 9:57 am

Newold1 wrote:
Tue Nov 06, 2018 9:21 am
I think you may be 75-100HP shy of your power goal with your combination in a low hood profile Corvette and a regular street driven car in a N/A engine format.

It will take a long duration high lift camshaft to get the engine producing those kinds of power with some pretty big flowing heads and a LOT of Compression! It would need something like a well setup Holley HIRam intake. Factory vette cams can operate at 7000rpms easily because they don't have the larger spring pressures a camshaft that would be needed to feed this level of power and higher rpms it will take to get there.

I don't believe there is a hydraulic roller that can do this for you even with the best valve train design.

If you want to see the LSX that can get there you need to take a look at the Camaro LSX COPO engines and you will probably realize why they would be a difficult BITCH to drive dailey on the street.

I am not trying to pupu your project but I think based on street driving acceptable manners and the restrictions of a low hood clearance and cooling issues on a ZO6 Corvette you may want to look at lessen your expectations for power level and driveability and plan your build around a workable solution
-OR slap a supercharger on the engine like GM did! JMO
I think we will just have to agree to disagree. SAM's COPO 427 made 825hp/650ft/lbs with a .641 lift limit and stock ls7 casting heads. Potentially poor drive-ability doesn't bother me. The engine already 32 degrees of overlap@.050 and 13.3:1 compression before it broke. There is also no mention of me wanting to daily drive the car. It gets 3000-5000 hard miles a year put on it.
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Re: 429 sbc ls build

Post by CGT » Tue Nov 06, 2018 10:06 am

Newold1 wrote:
Tue Nov 06, 2018 9:21 am
I think you may be 75-100HP shy of your power goal with your combination in a low hood profile Corvette and a regular street driven car in a N/A engine format
I disagree, and mostly because he didn't mention hood limitations, or being bound by compression issues, or driveability confines, or "cooling issues" on a C6Z which I'm not sure what you mean by that. A non-handicapped 429 cube, high compression 12° , dry sump, titanium valved engine with 2.205 intake valves on ethanol can't make 1.8hp per cube?? Really?
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Re: 429 sbc ls build

Post by Rowdy Yates » Tue Nov 06, 2018 10:27 am

750 + easy....... With worked heads. Cam and compression. Easy money.... Again to easy.... Solid roller would have produced more HP on the Sam tech 440 Ls 7. If you go solid roller you Won't be going back to a hydraulic roller.

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Re: 429 sbc ls build

Post by CGT » Tue Nov 06, 2018 10:45 am

Rowdy Yates wrote:
Tue Nov 06, 2018 10:27 am
750 + easy....... With worked heads. Cam and compression. Easy money.... Again to easy.... Solid roller would have produced more HP on the Sam tech 440 Ls 7. If you go solid roller you Won't be going back to a hydraulic roller.
The Sam engine is essentially a solid roller chief.
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Re: 429 sbc ls build

Post by CGT » Tue Nov 06, 2018 11:57 am

Rowdy Yates wrote:
Tue Nov 06, 2018 10:27 am
With worked heads
What does that mean specifically?
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Re: 429 sbc ls build

Post by A_VAS » Tue Nov 06, 2018 12:45 pm

I don't have a lot to add on your questions....but I did just use a set of those Mahle similar pistons (new p/n with 1.0/1.0/2.0)
they are a good bit lighter than stock, so plan on re-balancing your stock crank
the milled .085 heads I'm guessing you won't have any radial clearance with the valves...even though they have reliefs they won't clear radially with the milled heads.
May want to open those eyebrows up when it is in mockup state.
(i used the carbide stem mounted cutters from Lindy tools, mounted in the milled head, chucked up and spun with a drill).
too lazy to make power w/o boost

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