[laynlo15]

Whats nice about the Turbos you can have a softer launch and bring the power on a little later. You can do that with any FI but probably easier with the Turbos.

[parish8]

Originally Posted by laynlo15

Whats nice about the Turbos you can have a softer launch and bring the power on a little later. You can do that with any FI but probably easier with the Turbos.

With the 2 step and converter I can brake boost to any psi I command and an rpm as high as 4000rpm. If I can get it to hook it should be crazy.

[laynlo15]

Yes I would agree, 1100 rwhp is crazy. You'll get in the 8s with no problem. I wish you'd bring it to the Camaro Fest. Love to see it run. When is your next time out and where do you think you'll go?

[parish8]

Friday I was pushing my car pretty hard and something internal let go. I made 15 runs in 3 hours on a warm day(85deg, 3200 da), I was working on my 60’ but also turning up the boost in the higher mph’s. Ended up running 6.00 letting off early with a less than stellar 1.46 60’. May have been a new best if it hadn’t broken.

Logs looked mostly good. A/f, fuel pressure, timing, boost all where I wanted them. After looking closer I see my coolant temp was pretty warm pre run. 220deg. Might have helped to give it a little more time between runs.

From what I can see without taking the motor apart I think I may have dropped a valve or had one seize and get hit. The piston is still attached to the rod and does not look to be broken. I will have it apart in a few days and know more.

Thinking I need a used motor and then swap as much as I can over. Buy one new piston, new rings, put some better valves and maybe guides in the heads. Might do main studs this time.

[ShizzySupra]

Thats a bummer man but you gave that thing hell.

[laynlo15]

Hey that almost happened to me, valve nicked the piston but mine was minimal damage with just a bent valve and cleaned up the nick on the piston. Put it back together and mine happened after 4 back to back runs without lifting the hood on a 90 degree day. Plus I think the rev limiter was a bit high and may have over revved as I had someone else do the initial tune and I guess he changed the rev limiter and we weren't aware of it so it kept spinning the tires badly in roll racing and shit happens after 4 runs in a row it was floating the exhaust valve as all the seals were beat down or completely torn off. Sorry to hear that and hope you get it up and running before the end of the season. Hopefully nothing else happened

[laynlo15]

I did the Arp mains studs and head bolts.

[parish8]

Originally Posted by laynlo15

I did the Arp mains studs and head bolts.

Did you get a line hone after the main studs?

[oldman]

TSP says the same thing. I think it is kind of strange to need a hone. I've always said if the crank spins free while the mains are torque.... all is well. Dunno. The studs would have a slight tendency to load the whole bore, vs bolts that tend to load the closer threads...

I do know the second time I put the heads on, I dropped like 10 ft -lbs off the head stud torque and they were still hella tight. Way more than the bolts, forget now. But WAY more than the LS stuff. Why? Dunno.

[laynlo15]

Probably my machining bill was pretty high, but can't say for sure. I'd have to dig up my invoice.

[L78toLT1]

Originally Posted by parish8

Did you get a line hone after the main studs?

My machinist is the most anal guy you could ever hope to meet. He miced my motor 10 ways from Sunday. The mains were fine with the arp studs. . He was expecting
It to need line honing but it didn't. Crank spun nice and free with the mains torqued.

[parish8]

Yep, dropped a valve. The spring, retainer and locks are all still in place. Not sure if it stuck and then got broke off or if the head just fell off. This isn’t an area I was really worried about.

I doubt I will get lucky but I am hoping the cylinder isn’t destroyed.

[oldman]

I'd check for telltale contact marks in the valve relief area on all the other 7 pistons.

My tuner is saying that the ramp profile of my cam is partially responsible for my lifter failure. Whatever cam I'm going to, it will have less lift, and a smoother ramp, especially on the deceleration.

Last you can check the comp cams conical spring white paper and note that dual springs can have some funky oscillation leading to very low spring pressure at certain harmonics and high lifts. The problem I have with the conical springs is all of them have some serious lbs / inch. I don't know if I want to run that on a street car. Don't see any problem in a race car.

I'd look at this cam:http://www.cammotion.com/gen-5-lt-ca...-5-vvt-delete/

and spec at .600 to .612 lift. Supposedly cam motion and BTR have better valvetrain stability in their profile

Texas Speed does have a good price on a darton sleeved short block. I think Pray is a vendor. They are just north of Austin.

[oldman]

https://www.briantooleyracing.com/di...11536r2-8.html

this might be a better piston choice for high lift cams. Don't know the weight, I think the factory is 469 grams (from memory).