65LSXNOVA

That is my main goal.

DualQuadDave

iTrader: (6)

There is some good advice posted, but quoting dyno tests is not everything. Dyno is a static environment, running in the car and living with it is another. For me, the math is simpler. 417+compression+4000 stall+3000lbs+235 rear tire=single plane w/ a big *** throttle body. It'll be faster, easier to work on, wider powerband, and easier to upgrade if you want more later. JMO, every cook has a different recipe, just do what works best for you.

65LSXNOVA

alot of great info in these posts. I like the idea of the single plane.

SlowTBSS

Heres my engine, you can see what is achievable with some good parts. It's a 100% street engine. I think another intake could net 20hp with the right intake. Also would have cammed more if the vehicle was lighter.

It did make about 18hp more with a vacuum pump we borrowed from another engine in the shop.

https://ls1tech.com/forums/dynamomet...gas-build.html

65LSXNOVA

very similar to what I'm planning. Your has a Ever so slightly larger cam( don't know if there would be a measurable difference) About the same compression. Same intake( ill port myself). Heads are very compatible also. I do have a brand new set of factory LS3 valves i thought about cutting down to fit the tfs 235. If I made anywhere close to that power i might have to get the converter retightened

JimMueller

iTrader: (9)

What are your options to tune the combination? Are you using an OEM ECM, Haltech, Holley, etc.? Are you tuning it yourself or at a shop? Over the last 20 years I've noticed a regular gap between being told on forums to "get a better tuner" and the tuner stating "choose different parts". If you're driving it everywhere with family, then you they may desire better idle & part throttle behavior. It's commonly recommended to use a 92mm vs 102mm TB for easier tuning with OEM ECMs. It's also commonly suggested to stay under ~12* of overlap at .050" valve lift for better idle manners, perhaps with better CoD of the TFS235s one can get away with more overlap without significant side effects. I like @Kawboom 's comment... maximize fun in the vehicle... define the conditions under which you most commonly want to have fun with the combo first. Try to find that balance between driving family around & the desired 9s passes.

I opted for 4032 alloy pistons as I only desire a naturally aspirated engine, most of the miles would be low-load and I liked the additional durability under those conditions. I also didn't want the cold rattle associated with 2618 alloy. Those pistons happened to come in with slightly smaller valve reliefs to bump SCR. Depending upon where you want your area under the curve to be, the TFS 235s may have high enough CoD to get by with less cam intake duration and pickup some part throttle torque without sacrificing too much HP above 6000. If you're not worried about carrying power far above 6500 (and don't want a significant tq hit below 3500RPM) then I'd stick with a ported LSXR(T) or XS LS3 vs a metal short runner intake. $0.02

65LSXNOVA

car is running holley term x. I've only been the one tuning the car. Tuning and drivablitly tuning hasn't been a problem I've got that under control. My past combo had 9 degrees of overlap and I got it to idle really well. I would think the extra 6 degrees of overlap would be absorbed by the 40 extra cubic inches. But I get what your saying as far as driveability with the family and having a enjoyable car vs chasing a 1/4 mile number.
I was also wanting a 4032 piston as I understand they last longer than the 2618 forgings. If i can keep the combo the peak at 6500-6600 and shift at 6800 or so id be happy.

JimMueller

iTrader: (9)

When I was looking in 2019, the only quality LS 4032 forgings I could find were from SRP & Mahle. I don't recall SRP having the right size, but Mahle did. Katech offering Mahle in their short blocks relieved my concerns. I chose their 930223280 which appears to have been superseded. Maybe something in this catalog will interest you.

ls-6-2-flat-top-webpage.pdf (mahle.com)

65LSXNOVA

yeah it doesn't look like wiseco makes a 4032. I'd be fine with a SRP as they make a 4032 with a 10cc dish like I need.

JimMueller

iTrader: (9)

Maybe I overlooked it, where does the 10cc dish fit into the equation? That seems like a large valve relief for a flat-top piston. My Mahle's were ~.0013" below the deck, so we 0-decked the block.

65LSXNOVA

my tfs-235 are milled to 61cc

JimMueller

iTrader: (9)

Fel Pro 1041 head gaskets - advertised as 4.135" bore, .041 compressed

There are also the the FelPro "1161 L041" & "1161 R041" which are advertised as 4.100" bore & .041 compressed
https://www.summitracing.com/parts/fel-1161l041
https://www.summitracing.com/parts/fel-1161R041

chamber 61cc
head gasket thickness .041
head gasket bore 4.135
Piston to deck clearance, unknown, assuming 0 decked
stroke 4"
bore LS3 stock + .010 = 4.075
Piston dish volume 10cc
Rod 6.125
Top ring land height estimate .225"
Piston to wall estimate .002"

I'm getting about 11.7 static compression with the above without crevice volume, is that what you're aiming for? The 4.100 gasket is negligible, but a hypothetical 5cc valve relief instead of 10cc would raise compression to ~12.4, which Scott indicates is safe if you have 93 octane with those heads. So maybe a range of valve relief ranges between 5cc and 10cc will give you a wider variety of piston selections. I wouldn't order head gaskets until you see where the piston sits in the hole, and potential adjustments to optimize quench & compression.

Che70velle

iTrader: (6)

Agree 100% here. You have to mock everything up and take careful measurements, before you order gaskets. You have to build the engine before you actually final build the engine. Details matter here.

65LSXNOVA

100% agree.
Block is at the machine shop getting line bored and square decked. So il lmeasure piston height after I assemble the bottom end before ordering HG. I'm going to try and run around .038 quench.

Che70velle

iTrader: (6)

Measure height on all 8. I see variances all the time. Order gaskets based on tallest (farthest out) hole. I’m .035 quench in the 434 fwiw.

65LSXNOVA

those are pretty close to what I was coming up with. If I go with the SRP pistons they have a 1.115 comp height and should be above the deck some. So head gasket purchase will be one of the last things. I've never ran more than 11.88-1 compression so i know i can get away with that much compression on pump 93. The newer ford's are 12-1 but are direct injection and I've heard you can run more compression with DI. I personally don't have experience running over 12-1 on 93 with multi port injection.

helicoil

iTrader: (104)

I ran a LS3 416 in my 66 deuce. I have been 6.27@111 and 9.75 @ 137 with it at 3100' DA with 78 GOW. I ran 11.5:1 and see no benefits in pushing that on 93 octane, especially with a short duration cam targeting a peak HP at 6500 RPM such as what you are looking to build, IMO the risk is not worth what very little HP could be had from the small increase in compression. FWIW, I ran a much larger hydraulic cam than what you are discussing here. loose converter, TH400 and 4:11 gears, 3250# race weight.

I recently ran someone's Frankenstein M311 headed 427 on the dyno, 11.5:1, 248/254 hydraulic roller and it gained 30HP going from the taller CID LS3 4500 top 4.0 to the shorter 4150 Holley split LS3 carb style intake. Granted this was using a 4150 850 cfm Ultra XP Holley on both, just swapped manifolds back to back. Interesting result nonetheless.

Nice car, good luck with your build.

SlowTBSS

11.8:1 with .036 quench distance running on 93 here. I talked to Tony about cutting the heads a tad more to bump it up a little(2cc less) but he said the gains were miniscule and with my vehicle being heavy it would be more prone to detonation because of the extra load. Just wasn't worth pushing the limit that much. We did measure all 8 holes and set quench that way as well.

65LSXNOVA

so you ran 9.75@137 on motor? Your 1/8 mile mph is really good.

helicoil

iTrader: (104)