Its funny to hear about it nosing over. Mine seems to want to take off when I goose it in fourth. Is that normal?
I'd want to know whether it actually noses over. Duke says it falls flat. It may simply be running out of breath.
Maybe. I know my car pulls w small valves. Stock even. Just bowl work and clean radius. Has new stainless stock replacements now. He will need to test it. Baseline the car. It’s all fun. Till you break something.
thanks for the info gents, I greatly appreciate the long distance troubleshooting. To describe what I mean by nosing over a little better, I’ll put it this way. From a stop, idle set at 750, if I smash the gas my converter will flash to 3k and the rear end is a smoke show. Bang second (reverse manual valve body w/ B&M’s quick silver ratchet shifter) and the tires chirp and it’ll pull hard to about 4700k rpm and the rpms climb a significantly slower to 5k where I shift it. Then 3rd comes on strong as the rpms drop to about 3700 or so and it pulls hard just before 5k again. It just stops pulling at 5k-5200 or so. It’s like it runs out of power. Not so much a surge or anything, but a serious reduction in climbing of the rpms. I’ve stayed in it all the way to 5400rpm in second before and it wasn’t accelerating very hard to me past about 4900rpm. In the beginning it didn’t bother me as much since I was getting used to the motor’s power band and just assumed I had reached the end of it. Now that I’m a few thousand miles into this engine, it doesn’t behave up top like I want. I’d like to have strong power from 3k-5500 rpm and shift it around 6k or just before. Makes me think my cam just runs out of steam and my heads choke. They are stockers, albeit brand new. No porting just a 3angle valve job and all new hardware. I’ve been mulling around the idea of switching to the TA310 or 290-94h, as well as some aluminum heads. I’ll be staying with stock rocker arms since my budget is about 3500. I’m still $1200 or so light for the roller upgrade. On that, are the roller rockers seriously worth it? I get that they reduce valvetrain fatigue and allow for higher lift cams. But otherwise, juice vs squeeze? I thought about going custom grind, but honestly I really dig TA Performance and sticking with their products is my way of giving back to the buick R&D they do I guess. Their customer service and product knowledge has never let me down, and to me that’s huge. At the end of the day I don’t track my car ever. Just chop at the light and show off for my girl every now and then. So a 700hp track monster isn’t my goal. Really only ~500hp if I had to draw a line. Sheesh, there’s only a lap belt to save me if I balled it up! I don’t need another 200mph car. I have a hellcat to go fast. I just want a little more attitude from this old brute and a slight bump in the top end. am I on the right track here guys? Or are we talking more money than it’s worth. I mean the thing runs reliably now. I don’t want to piss it off and create a maintenance nightmare all the time. I do feel like the car is sorted in all other areas to handle the hp bump. Perhaps I should just save money and properly paint the dang thing and leave it. It goes like hell now up to a point, all while looking like it’s “under construction”. Priorities...power power power power....meh, paint. Such is the struggle I guess. ♂️
☝Sorry for the long story, sleeping is secondary over here for me right now. Guess I just miss my car! Lol!
Running faster ETs by means of higher flowing Intake and Exh tracts has nothing to do with a motor not reving above 5000 rpm on a level road even if it's already well on down hill part of the motors HP curve! Whatever rpm a motor can attain cleanly out of gear should be able to be done in gear, though it will of course take longer! As posted before your cars fuel system likely needs a up grade, and for sure if your going for more power then you have now it will need a up grade, so get it done now!
Head flow is everything in these motors. It enhances every part of your combination. It doesn't nose over, it just flattens out. When my motor was all iron, I remember thinking I was out for a Sunday drive at the top end of the track, so I know what you are talking about. As I have said before, the biggest thing I noticed when I swapped to the aluminum heads was how it felt at the track. It pulled harder everywhere including the top end. I was fortunate enough to be able to get my car down the track pretty often, at least once a year. The biggest change was the aluminum heads by far. When all was said and done, I gained over 1 second ET and close to 11 MPH in trap speed. With just the heads alone, I gained 7 tenths and 7 MPH, the SP1 and 1000 DP carb got me the rest of the way. Duke, I say just buy the heads for now. Spring for the entry level porting, it's a no brainer. The only thing I recommend is to mill them to get your SCR to 10.5:1. Leave the cam you have, stock rockers are fine. It will make a huge difference. It would be nice if you could get the car down the track before and after. In my experience, a car always feels faster than the time slip reveals.
The heads will definitely help. But the fact the car falls flat, if you may, might mean another issue. Fuel or weak spark at top like coil saturation. Get the heads done like Larry recommended, but dial in your combo first I believe when you get home.
If your fuel pump has a fuel return, you can block it off for a few test runs. That causes more fuel pressure which sometimes helps with marginal fuel delivery. As for running out of fuel, if it will rev to your desired redline in 1st but not in 2nd or 3rd, it could be fuel. Once, mine would actually act like I was stomping and letting off it was so starved for fuel.
First step is to temporarily rig up a fuel pressure gauge and tape it to the windshield. You can do that with a section of fuel line hose and a tee. See where the fuel pressure goes under high demand. With the Stage1 pump, it is easy to tee in a pusher pump near the tank. I used a Holley Red for years. You can even use a relay connected to the kick down switch to turn it on. From the TA Catalog,
I had a similar issue in my 65, it was ignition. I was running a Pertornix I on the resistor wire (which you're supposed to be able to do), I changed it over to a full 12v and that took care of that problem. You havent mentioned valve springs either, have they been replaced recently with a spring spec'd to the manufacturer's recommendation? I'd say that cam would take something like a TA1125 spring, or at least something that gives you 125/300 lbs
I quoted Duke's earlier post (#14) about valve springs, they are the TA 1435 Stage1 springs. They should be up to it. O.D. 1.360 I.D. 0.835 100 lbs. @1.860 315 lbs. @ 1.360 Coil Bind 1.275
Had to look up the 1435 springs. The 1435B are stock springs. At first I thought that's what he had. Those would have been a problem.
Needs to fix his issue first. Get a good baseline and go from there. Great tests here to peorform for both fuel and ignition. Also make sure timing is really right. The small valves work and it’s proven by many here along w stock eliminator racers. Then upgrade heads and what have you. If you desire.
I'm with 70 GMuscle on this - your combo should be good for 5800 at least (dont do that too often, BTW if you like your motor.) Fix what you've got, if it works right you'll know it and wont be wanting for more power.
Oh, I definitely agree that you should fix what you have. My question is, is there anything wrong? If I could drive your car, I could probably answer that question. I remember when my engine was all iron, it definitely pulled harder down low and mid range than it did at the top end. I remember thinking at the top end of the track that it wasn't pulling as hard, but it was still accelerating, not flattening out. That was the biggest difference to me with the better heads. It pulled harder at all RPM. Very difficult to know exactly what you are feeling. There may be something wrong, or not. Do the checks to see. Check all the basics, make sure your timing is still correct, make sure your fuel pressure is adequate. You say your distributor is an HEI, GM big cap HEI? They were renown for dropping spark at higher RPM. It had to do with the epoxy coils running hot. I think the aftermarket has addressed those problems, but if yours is all stock, that may be a problem.
It’s an accel HEI I bought from autozone. I got the super coil for the top also. Then I recurved it and set the timing based on your power timing thread. That was about four years and probably 8000 miles ago. I haven’t fooled with it since, because it starts reliably when hot and had been running been running well.
Years ago, I had an Accel HEI on my 350 Skylark. It left me stranded multiple times until I finally figured out it was a defective pick up coil. I do not, understandably, have a good opinion of that HEI. Not sure about the super coil, most of coil advertising is pure hype. Not sure how to test what you have other than substituting another distributor.
