RamAir972003

Alright guys like I said this week I will be interviewing the man. We will have it Theos Bar and Grill in Grand Prairie so if you guys want to come and ask or just hang out let me know 972_824 0793. Angelo. If you guys have any questions post to thread thanks.

Beach Bum

What day and time ?

Vito.A

I'd like to know Darrin's opinion on the LS7 valve guide issue?

Also, does he still recommend the Raptor BBC cylinder head, or are some of the newer designs better?

Vette @ 71

In addition to his opinion on guide wear, what evidence/data does he have to support his opinion.

RGT

Is he still porting LS7 heads?

RamAir972003

I have info in Texas section call me 972-824-0793

Dirty Howie

Good luck with your meeting. Looking forward to review of what he says.


DH

RamAir972003

Thanks

427ZM

Speaking about the LS7's specifically, ask him about the heads he made for the highest HP Naturally Aspirated LS7 in the country. He built heads last year designed for his Engine Masters motor then sold those heads to John B. (Forum member). John has them on his LS7 Monte Carlo that is producing over 700 whp naturally aspirated.

Or about his cam and heads in his Camaro. That's a trick setup... He uses the VVT from the stock L99 to retard his cam timing up to 8* in the upper RPM's.

Or how his thoughts on flow changed after he had access to wet flow benches.

The guy knows heads. They guys knows motors. He is a wealth of info that will enlighten you to all things engine dynamics.

rockinSeat

As more cars go out of warranty, should the average Z06 owner be worried about dropping an exhaust valve? And by average, I mean a stock engine with an air intake and/or exhaust; a spirited street driver or amateur, but not a serious competitor. If so, what should a guy do? Can the problem be fixed? What about monitoring the problem or a maintenance plan?

For the avg owner:
Do you recommend the longer guide such as wcch?

What guide material? Stock PM, bronze, moldstar90?

What intake valve, exhaust valve?

Should the hollow sodium exhaust valves be trusted vs solid stainless vs titanium?

Roller or stock rockers?

What head setup for 100k miles on the street worry free?

atljar

He suggested bronze guides, a good roller tip rocker, and solid stainless exhaust valves for my build when he did my heads (street/strip setup)

vertC6

Well, then I have count him off of the list of guys to take advice from because if you see the spintron testing of a roller tip on a heavy solid SS exhaust valve at high rpm you wouldn't go that route.

LS7 are designed to spin high rpm, if you keep it under 6500 you can go with that setup, but if you go above that you simply have too much bounce off the valve seat. My .02

atljar

It completely depends on the spring used.

vertC6

A lightweight spring would be a crazy amount of bounce and I heavy-duty spring would be a lot of bounce. The total weight of the spring also makes a difference in inertia and controlling the valve.

In the spinton testing the lightweight beehive bounced less than the heavy duty dual spring.

Dirty Howie

Angelo

Ask him what he thinks about the spintron test results !!


DH

Unreal

Depends on cam, lobes used, springs used. People can't seem to get this through their head. Valve and rocker are just 2 parts of the equation. You can have roller/solid valves stable to 9k if you wanted with the correct springs and other parts.

Dan_the_C5_Man

Absolutely - I am way more comfortable with my stock cam, YT's and 1511 setup than I ever was (or ever will be) running the stock rocker.

It is a system, one with several components - you cannot change out one (as was done in the aforementioned spintron test) while ignoring the others..

Unreal

And quoting one spring, one cam doesn't mean all are bad. Friend runs big nasty .750+ lift PAC springs on solid INTAKE valves on a ls7, and spins it to 7500 no issues at all. Springs wouldn't fit a stock head, he has MAST heads, but there are big springs that will control heavy valves.

RamAir972003

Copy due to issues with weekend next sat will be the day for the interview since Darin is swamped....with work...

rockinSeat

Hey sorry to bring this up, you don't have to ask if you don't want to...but since some have mentioned oil lately, can you please ask about long oil warmup times? For instance, if it takes 25 minutes for the oil to get up to 150, and your commute is only twenty minutes, could repeating that over and over be causing premature wear on anything? If not, that's great; I'll stop worrying.