speed_demon24

iTrader: (6)

Yep 10 bolt. Last one blew up with cruise control set at 80mph on the turnpike. I'm running the same general cam as bowtienut but they might be on different lsa's and advance since he is an auto and I'm a 6-speed.

draggin97s10

iTrader: (2)

I have fears that i will just be cruising along at 80 on the highway and mine will lock up....

Ed Wright

iTrader: (1)

200cc intake ports are more than enough for a 7000+ RPM 356". Certainly won't "suck the ports dry".

A properly ported factory manifold easily makes power past 7000 RPM.
Ask me how I know. Been there, done it.

If your 355" LT1 with LE 200cc heads isn't faster with a 250 deg @.050" cam your converter & gears are wrong. No dyno queen to it. Your car is just wrong.

My 260" SS engine with 175cc ports, 1.94" & 1.5" valves, & stock throttle body, HP peaks at 7300, varies less than 1/2 HP until 7700 on an engine dyno. I wish I was allowed 200cc intake ports.

Lloyd's factory castings make good power. The young man that bought my two year old 355" daily driver short block I drove before the 383" put a set of those on it with a GM 847 cam and it made 455 rwhp.

1995 T/A

I feel ya, my 4.10s chipped some teeth rolling through a parking lot( although I think it had to do with the guy that I bought the car from). I'm runnin 2.73s at the moment and I will attest that they are horrible with the six speed.https://ls1tech.com/forums/images/icons/icon7.gif

bowtienut

iTrader: (1)

Remember, we're talking stock PCM limit for this guy. A smaller cam than that will be quicker with good heads and his imposed 7000-7100 shift points.
Agree 100% with your other points.

1995 T/A

Just to be sure - I can shift at 7000 stock pcm?

Ed Wright

iTrader: (1)

Mine ran quickest with a 250-256 @.050" cam, on 106 centers. I ran many cams thru that thing with the factory PCM. Shifted @ 7000, ran through the lights @ 7000. On cool nights it would be cutting off just before the finish line.

If I remember correctly, Rick Abare's cam was about that size also.

Ed Wright

iTrader: (1)

Yes. Mine would hit that rev limiter on the first pass. Once the trams was warm my data logger would show the shift RPM 7050/7100.

1995 T/A

Thanks, I just hope my transmission can take it.

bowtienut

iTrader: (1)

I just noticed he said he's a 6-spd car. I have no idea on the ratio spread/ rpm drop in those. My caution about limiting to a 230ish cam might be unwarranted.

Ed, I'm taking it that you ran best with 250-256 cam in your 383. Solid roller too I bet, so need to account for lash. We've had this discussion before where I was trying different TC's to try to keep my little 350 from dropping to 5400 on the shifts. Fully aware that the additional torque of the stroker will keep the rpm spread tighter with any given converter.

1995 T/A

HAHA, yep m6 . The 6 speed gear ratios are a little more even than a 4l60/700r4. 4l60e- 3.06- 1.63- 1.00- .70 MN6 2.66- 1.78- 1.30- 1.00- .75- .50- rpm recovery shouldn't be a big problem.

Ed Wright

iTrader: (1)

A looser converter will keep it from dropping as far on the shifts, and make it like more cam. I never had one drop that low at the shift.

Rob94hawk

iTrader: (1)

LOL! 2.73's are pretty damn awful. And I thought my 3.42's were bad. I've stalled quite a few times because of them.

You sure can.

SS RRR

iTrader: (2)

Agreed wholeheartedly. I am still using LPE heads/intake that were normally "designed" for a 383 with a 211/219 cam and judging by the power curve (same heads/cam setup you tuned back some 15+ years ago), it supports alright power to 6800rpm. I thought for sure the curve would nosedive long before it does now...

96capricemgr

iTrader: (1)

People get confused between what is possible and what was possible with what they bought.

One vendors welded up heads and intake running out of steam by 7000rpm doesn't mean another vendors will just means the first vendors stuff does.

There are plenty of cars running hard on the AI 200cc stuff turning 7000+ with GM inake manifolds with relatively little work. I know other vendors remove more material and that is seen a a "better value" but when the folks who bought that "better value" endup swearing you need to go to a more exotic intake setup for engines held inside the stock pcm limits that should make one question what sort of "value" that was.

hvyss

Really? I am running the AI 200cc heads and their 22x/23x small HR cam with their big block beehive springs shifting at 6800-6900 all the time and hitting the rev limiter at 7k 200 ft before the stripe due to my 4.10 gears and the car is still pulling like a striped *** ape at those rpms. The heads are good for well over 7k.

Ed Wright

iTrader: (1)

All shop's cylinder heads aren't equal, and we don't race flow benches. Hard to not roll my eyes when somebody starts a thread "Post your flow numbers". :-)
Cross sections, the choke point, and velocity maps are what matters. You can bull **** the flow bench into some bigger CFM numbers and slow the car down.

Ed Wright

iTrader: (1)

Pat, if you had played with a Cam Dr enough you would know an aggressive solid roller profile is fast enough to more than make up for lash compared to a hydraulic cam with the same seat or .050" numbers. The solid roller gets bigger fast, by .100", .200" & .300" lift. That doesn't include more lift. You have much more valve open area. They just can't put the same kind of profile on a hydraulic cam due to valce spring limitations.

My last hydraulic roller was 242/248 @ .050", each time I went bigger the car ran quicker. The 250/256 solid roller picked it up more.

I test a lot. Dyno and track. I don't just throw **** together. If I tell you I tried it, I did, and I will tell you what I found. If I haven't tried something I will tell you I don't know.

Ed Wright

iTrader: (1)

Something I hope might help save somebody some grief:
The factory LT1 aluminium head valve seats are cast. If you go to build something with the more aggressive solid roller we use in Super Stock engines, with aggressive valve springs we use with them you need to have the factory valve seats replaced. I learned the hard way when I tried to finish out the last two points races this year. I changed my #2 engine over to that stuff. An intake valve seat broke @ 8300 in the lights at Houston. Came away with an intake manifold and timing set. Everything else was destroyed. Block and all.
If your going to update to 1000 lbs open springs be sure to replace your valve seats. Much cheaper.

96capricemgr

iTrader: (1)

These days though a lot of guys are using solid cams with a lot less spring that used to be normal.

That said new seats is not that much extra cost once doing a solid roller setup.