A couple observations of the SP3

A/F meter never changes. No lean out.

Trouble is I don't remember the exact RPM thru the traps to accurately use the calculator.

Have a TCI Saturday night special in it since 1997. It's never gained more than 18 MPH.

 

Valvesprings been checked somewhat recently?

 

3 different head/spring combos were all the same.

 

Yea id be definitely getting that TCI out of there man you will surprised at how much different and better a good converter will be

 

PM was sent to JW. He's looking into it.

 

you need to make a decision. are you going to race or play at the track. I'll assume its racing.

1st, the 3.42's are for grandma. you need to step up into the 4's and real slicks.
2nd, the real 350 cams kick in about 3500. so you need to get a converter that minimum rpm. its true, if your after performance, the engine doesn't wanna race until 3500. I've used a 3500 in the door car and the rail. gotta go to 4500(reason for slicks) to make the 60' better and the rail faster.
3rd, now your car doesn't like all this because the suspension is out of tune. you better start to read and listen more about this.

the above partial list is after you figure out how to make the 350 run. I ran the 650 on the s/p. with a s/c, supposed to up the cfm a lot. the same 650 sits on top of the s/c. the 350 just reacts differently than other engines.
but beware when the alum heads arrive. that will be a whole new learning curve. I wish we could go the 4" bore route for them.........:grin:....maybe....

 

Sonic testing Andy's block, it tested thick enough to make it a 4.00" bore! I'm sure there are more than just that block that will go that big? I wouldn't recommend going that much overbore if someone wants to run boost though unless the block was filled up to the deck then that might work if we can get head gaskets that would hold the pressure in with that bore size?

With the block at a 4.00" bore and a 3.990" stroke would be a 401 CID sbb, I have been trying to nudge Mart that way for when he does a new build when the heads come out. :Brow: (we'll see?) That is if we can find another block that will handle that much overbore?

I suspect with 401 cubes N/A with an SP3 a 750 CFM carb would probably be what it wants I would hazard to guess. 401 CID and weighing less than 400 lbs would be a great way to go is what I'm thinking even if the block needs to be filled to go that much overbore, I think the fill isn't more than 10 lbs per side so less than a 20 lb penalty for the fill? To get the coolant from the heads with the block filled up to the deck, the freeze plugs on the ends of heads may be abled to be threaded with a pipe tap to direct the coolant to the timing cover where a corresponding hole will need to be drilled and tapped to connect the 2 holes.(custom race machining if anyone is wondering what the flock I'm talking about, LOL) Driving an engine on the street with the block filled shouldn't be a problem using an oil cooler.

So if anyone was wondering what the potential of a sbb 350 is, the above just scratches the surface! Its just to bad the General didn't raise the dam cam when they raised the deck on the 350!!! If they did that a MUCH longer stroke could fit in there.


Derek

 

Found your comment......

 

gsjohnny has it all correct. When I first put a cam in way back in 1983 Comp Cam 268 didn't know crap then just did it, put it in straight up on the dots, didn't even rev the thing up when first starting it up let it sit there and idle. Changed the oil after that and went out and drove it. Had the 256 gear in it stock stall, had a shift kit in the trans that made it fast right?

Put on a 4bbl intake and bought a Holley 3310 vac secondary carb I think it is a 600 cfm.
Guess what, the car would not turn on till it got to 3500 rpm just like Johnny says then it ran like bat out of hell Ran 16.10 in the quarter. 2nd gear thru the traps, would do a 100 mph in 2nd gear. Would barely do a 100 in 3rd with the 2bbl on it before the cam change. It had duals with turbo muffs coming out the side in front of the rear tire.

Put in a 373 gear, Hey guess what, it still took till 3500 to get going now ran 15 sec in quarter. Tried a 650 Holley dbl pump spread bore, still took till 3500 to get going.

Put on a Thermoquad carb ran 14.89 in qtr. guess what it still took till 3500 to get going still had the stock stall in it.
This carb flooded out during my 2nd run and the motor broke the crank in half and I still was able to drive home. At this time the year is 1993.

Rebuilt the entire motor at a real race shop and put in the TA 510 cam, Had the heads sent to TA and they had them ported for me and I put in notched forged pistons, index ground crank, 73 rods, TA intake, new cover where TA set up the oil pump with the larger gears OMG the gears are too big, wear out the dist gear wrong! Engine came in at 10.6 compression. MSD 8548 dist in there had all the oil mods done on motor, SFI flex plate, Shop cross drilled the crank, Hughes 3500 stall convertor, 5 grand in parts with the heads and 3 grand to have put together. Plus a 500.00$ dyno session.

Guess what guys, it STILL TOOK till 3500 to get the engine going when in the car.

Now you have Demko's car. 342 gear 413 cam 1 cam below mine I do not know his compression but he does have a 3000 stall convertor.

Car runs good with the TA intake, now he puts on the new SP3 and it slows down.

I will bet you when he shifts into 2nd gear the rpm drops down to 3300 rpm with that 342 gear and when it gets into 3rd gear it really struggles to get the rpm back up into the zone of running correctly which is probably about 4 grand now for the new intake.

That is what is happening with the 10 mph loss in the 1/4. It doesn't have a darn thing to do with fuel the engine just can't recover fast enough to the 3rd gear shift.

You now need at least a 3500 stall convertor and a 400+ gear to make this intake work. Because it aint working till it hits 4 grand I will bet on it.

Right now I am barely turning 5 grand going thru the traps and I have a 373 gear, 28" tire. More like 4700 with the convertor locked, I just found this out at my last track outing this summer.

What rpm you think Demko is at going thru the traps 4 grand maybe? The intake hasn't even turned on yet right there is the problem.

I bet you if he had my nice loose a** 3500 convertor that can be foot braked to 3 grand would make a big difference and add a 410 gear and the crap will hit the fan and with a DP carb of course.

He should be able to hit 6500 but he says it doesn't seem to want to go past 6 his motor is not balanced.

My engine is balanced and it was spun to 6400 on the dyno.

Forgot one thing, Nitrous changed all of that. It made it act like a 455. Big Torque

 

It for sure is lifter chatter, definitely not detonation.
No race gas, just 93 Sunoco. I tried 112 at Norwalk, I slowed down

 

Fox's den, shift recovery was mentioned.
Not sure what the butt dyno says...

 

Tip for racers: it's common (or so I thought it was) knowledge that 3500 RPM is the 'sweet spot' for pretty much any performance cam/engine when overlap begins to take control and really flip the engine's switch, so to speak. This is usually the lowest number, depending on the setup, duration, head flow, etc. but in general, for a regular 'street/strip' combination, this is your magic bullet. Aim for 3500-6000 RPM and the rest will fall into place (if you know what you're doing, that is.) Lots of variables, and I'm sure 101 people will have 101 opinions on it.

I learned this decades ago while learning from a top engine builder in Atlanta, among other things. Yes, some of my knowledge is decades old too. I'm not a youngster just showing up to ride the coattails of someone into glory. I've been there done that and seen a few things myself.

Anyway, back to the regularly scheduled this and that back and forth.


Gary

 

I "meant" to pay attention to the tach. last track visit, as far as what the rpm "drop back" is after the 1-2 shift, I forgot
But I AM curious about it!
I don't think the track is going to happen this Sat. But I will check to see this (rpm drop) on a stretch of Rt 8 (divided 2 lane)
I also want to see how my Holley behaves.

 

I just looked at my time slips for the season, they're ALL in the 18 mph range between 1/8 and 1/4 mile, EXCEPT for the SP3 runs.
Even my runs at Super Summit with crappy track prep and spinning off the line, whatever my 1/8 mile mph was my 1/4 mile was 18 or so faster, but still in the 18 mph range, INTERESTING:shock:

 

Yep, replaced 'em early spring with same ones (TA dual spring for the 413) I forget the part # 1130 maybeo No:
I did notice on break-in of the cam couple years earlier, with just the outer spring, the lifters were much quieter.
Installed height/pressure checked.. all good
Full lift coil bind/pressure checked.. all good

 

Demko, I did not mean to be disrespectful to you in my last post I was just trying to be realistic about the SP intakes in general. If anyone has read about these things they just don't turn on till 3500+ rpm.

Here is what I am willing to do. I currently have my DP 750 Holley off the car and I was changing the jets in my nitrous plate to cut the power down. I took the bowls off the carb to give a look see inside since it had been at least 5 years. I was going to change the pump diaphragms like I always do before the season starts to keep problems away.

I will bring this carb to you so you can see if this will get you back in the ballpark. I will also bring my K&N Flo-control air cleaner which directs the air down the carb. It is a drop base and is 4" high and 16" across yeah its big.

I have to put the bowls back on and put in the new diaphragms for the pumps. It is jetted at 70f 78r so it should be fine for you.

I can bring this to you tonight or sometime over the weekend. Or you can come to me here I only live down in Ravenna so I am not really that far away probably 1 hour. I have no problem bringing it to you. you can shoot me a PM on where you live with a zip with ph number and I can punch it in my GPS to get to you. Just tell me the best way to get to you in case some spots are not good to go thru.

I want to see you put up some good #s with this set up you have.

But I do think you should start to think about putting in a 373 gear at least and put in a 2004r trans and a little higher stall.

When I put in the 200 trans I went down from a 3500 convertor to a 3000 so the nitrous would not blow it away like it was doing with the 350 trans. I was blowing it to 5 grand on the nitrous hit. Talk about a launch out of the Hole!

With this trans my 60 ft went from 1.80 average to a 1.98 but I with the lower 1st gear I was making it all up by the 1/8 mile and I ran the exact same times with and with out nitrous. went 1 mph faster on the nitrous 113 with 350 trans 114mph with the 2004r trrans.

Well, that is my offer let me know if you want to do this.

Later,

Guy

 

I think maybe that come alive thing is due too the cams you're using with 110 or less LS. Thats just where they start to become efficient. Of course the single plane will make they change more noticeable. My Crower with 112 LS pulls hard from idle.