That people sing the praises of the Buick 350, how great of an engine it is, with its low-mid range grunt and higher RPM (with a 4 barrel) power, how durable it is, etc. only to take a perfectly serviceable engine and pull the stock cam out of it and put in the xxx camshaft with a lopey idle and then scratch their heads when the engine is junk a few thousand (or less) miles later, or end up disappointed with its weaksauce torque output and mediocre high end pull because the engine is fighting against itself, working against its original engineering intent? The engine impressed you because it was built a certain way from the factory, and then you want to change things around to 'improve' it, only to make it worse or ruin it altogether. o No: THE best way to improve the engine is to blueprint it. Use what's already there and massage the parts so they can work better in unison. Change things around and things can go south very quickly if you do not know what you are doing and/or do not know/understand the Buick 350. Think you need a high lift cam to get more performance? Think again. There are super stock racers who use stock lift cams, add more duration to raise the powerband, and are producing MORE power than your typical 'street/strip' engine, using no port work on the heads and stock intake manifolds due to rules limitations. Imagine what could be done with no rules to bind you? The camshaft specs are a secret in order to remain competitive, but I'll tell you right now what the secret is because I for one understand the engineering behind the Buick 350: asymmetric lobes. This is NOT a chevy 350. /endrant Good luck finding a camshaft beyond the stock one that does all these things. Everyone's camshafts are '70s or 80's technology using retrofit/afterthought SBC ripoffs that simply don't work in a Buick 350 engine, or at the very least are inefficient. The ONLY cam that is worth using is the Federal Mogul CS647 camshaft. I can give specs for a roller version of this cam for anyone who is interested, which will give your stock blueprinted engine 434 ft. lbs. @2600 RPM and 324 hp @4900 RPM* on premium pump gas, using TA's dual plane intake and 1 5/8" primary tube headers, and will outlast the Federal Mogul flat tappet OEM camshaft (which is to say, a very long time). *these numbers were obtained using a dyno simulation program and my own recipe of number crunching averages @varying RPMs (which has been shown to be fairly accurate), so are probably not 100% spot-on accurate, though the actual real-world numbers wouldn't be too far off. Suffice it to say this roller version shows much improvement over the flat tappet version, which comes as no surprise. Notice the even wider powerband the roller version has over the flat tappet version. An even larger roller camshaft which is to be used with the upcoming TA aluminum heads will be available once the specs on the heads are known, which will provide even greater power gains and still retain excellent longevity and efficiency of the Buick 350 engine. Buckle your seatbelts for this one. Gary
Hey Gary Just as an FYI to add to your knowledge base. We have built valve lift limited engines for stock classes. The cam lobe profiles are Trapezoidal, mechanical flat tappet and are very harsh. Open valve spring pressures are heavy to keep the lifter tracking over the two lobe corners. Idle rpm is kept above 1200 rpm to maintain enough oil pressure to keep the cam healthy. The lift limit is .450" measured at the valve for most circle track car and boat classes. In NHRA drag racing "Stock" the lift limit is .430" Paul
I remember you telling me about that once some time back. Max duration for limited lift and super wide lobe peaks. Now that is taking it to the extreme! Talk about an intense profile... Gary
Is that blueprinted with the factory cast pistons and stock rods with the factory bolts? What kind of gains would we expect with heads that are mildly ported to correct casting inconsistencies and core shift? Say the heads now flow in the 220 to 230 CFM range without any loss of velocity. As we know stock heads flow just under 200 CFM on the intake side, so the above range is reachable with mild corrective porting. And for the ex. side the same deal but get it to flow in the 150 to 165 CFM range which will put the in. to ex. ratio around 70%. We know better than this can be achieved because of the heads Anthony Mackley ported that were 250 CFM on the intake with over 70% in./ex. ratio, if I remember correctly I think the ratio was closer to 80%. Just wondering how well the stock and your roller cam design would respond to more flow and a better ex./in. ratio, would that raise the RPM where the power peaks or will the more air raise the HP and torque at the same RPMs? Thanks. Derek
I agree with most of what Gary is saying about making it something it was not intended to be to the point we have not had parts to make it anything else. Now that we have an intake (untested) that may allow more RPM the porting and bigger cams may allow a dependable engine with higher power bands. The heads when and if they arrive will be another thing we won't know about until they are released and tested. And did I mention testing? Still waiting for some SP3 results other then golly and gee sure looks pretty.
You arent allowed to mention that . You will get riduculed and scorned. Oh and you still wont get an answer
"There are super stock racers who use stock lift cams" You need to do some more reading of the rule book before making this statement. You must not be a super stock racer. There is real racers that read this so get your info correct or ask real racers that actually have raced cars that qualify at these races. too funny! Dan Wilson
I install this new SP3 intake on my bone stock 350 bracket race car with no mods to the intake. This car is an exact duplicate of my nhra stocker except the 350 is original 99000 mile engine that was in the car. The idle had to be increased from 800 to 1100 to make idle in gear with out stalling. Other than that no problem and throttle response is very good. Car leaves very good but a loss of 2 tents in compared to the stock 4 barrel intake. A jet change may take care of this loss but I was hoping for a gain beings the intake weighs half as much as the stock intake. Will most likely have to port the intake because the intake ports are smaller than the heads causing a restriction. The car did run more consistent 9.30 in the 1/8 70 mph. Was running 9.10. Dan Wilson
If you are referring to my post, I was simply adding info concerning the limited lift classes that we were involved in, not to say there aren't other variations of the class. Thanks for your info on the SP3 intake Paul
Dont you know whatever works on a Stock/Superstock combo, will work on Joe Schmoes 4000lb ,low compression,undergeared,underconvertered stocker.:TU:
Problem is SS racers won't share! That's about what I expected it would do on a mostly stock engine. I would increase the pump shot to help make up for the loss. If your converter was about 3000 stall it would not be an issue.
Theres no hook to bite............... lol You are the only one i have ever reached out to on this site for some advise so take it any way you want( should be taken as a compliment ) The reality is 99.5% of the 350 Buicks on his site dont even make 1hp per cubic inch regardless what their owners think You and i both know you dont need this intake to achieve that If their was as much effort towards current parts maximization as there was towards future parts dreaming,then maybe ........
Cool! Just wasn't sure where you were going with the comment. Looking forward to see what the new head brings to the table. There are some projects here that are counting on some good flow numbers after porting. I know... you just got done talking about future parts dreaming.
When I refer to 'blueprinting,' I'm referring to using OEM style parts, not necessarily made of the same material, though cast pistons would be considered to be part of this package, yes. Better bolts on the rods and mains (and heads) would be highly advised. Ensuring each runner flows as closely to each other as possible, as well as compression and displacement variations between each cylinder. Bearing clearances need to be as close to each other as possible too. Instead of everything being all over the place as is typical with a production engine, things would be much closer in relation to other relative parts. Stock rods retained, stock valvetrain, including camshaft. Lifters being the 'camsaver' hydraulic type would add to the camshaft's life, providing there was good oil pressure and volume, which would exist in an engine where clearances and tolerances were closer inline with each other. Freeing up power that's already there would be the biggest gains in power, though improving head and I/E manifold velocity will certainly add to it. These engines will last as long as modern inline 4 cylinder engines if built properly. Power output would be increased considerably, but as far as attaching a static number to what each improved part would give, that's a dynamic not so easily ascertained on an individual basis. The engine functions as a whole, and each part works off the other. Improvements in one area might not be as good if another area wasn't improved to match it. You already know this. This has been a point in many of my posts in the past, that may have very well been overlooked or misunderstood by many. It would do both. The increased airflow/velocity will increase power output across the entire RPM band, while raising the peak RPM points. The asymmetric lobe design allows the cam to act small at lower RPMs while increasing its ability to move more air the higher it revs, up to a point. This is the foundation of why it has a wide powerband. This type of cam design is not intended to maximize power output by itself alone, but instead works with the parts around it. The more the engine flows, the more the cam will allow them to flow. Restrict airflow, and the cam acts small. Increase airflow, and the cam will act both small (at lower RPMs) while acting larger at higher RPMs, while being gentle on the valvetrain to ensure maximum camshaft longevity. The big block cam acts this way too, only more radically so on the exhaust lobe since it has a much greater hurdle to overcome with more cubes trying to breathe through a restrictive exhaust. Gary
Testing is critically important. Attitudes are the only real thing that get scorned around here. Welcome to the thread! Gary
I never specified the exact lift, only that they were 'stock', meaning not the radically high lift that everyone believes you must have to have a performance engine. No, I am not a superstock racer. I welcome all here, racers (both real and bench), engineers, and knuckle draggers all welcome. Perhaps I misspoke? Was it the stock class then? My apologies if my semantics were inaccurate. Gary
The problem with idle should tip you off as to what the intake needs... The (lack of) plenum velocity is hurting your performance over the stock intake, so needs either a smaller bore carb or a 4 hole spacer, similar to what is built-in on the stock intake you're comparing this intake to. Rejetting the Qjet probably won't do much unless you couple it with a restricting secondary opening that only permits it to open to 60% or 75%. Even this may not be enough without the 4 hole spacer. Expect it to perform even worse if you port the intake runners on the SP3...you need that velocity and it is not a restriction, particularly with the stock engine. You're the pro, not me. Follow my advice on carb/spacer choice and no port work on intake, and if I'm wrong, I'll concede and shut up. All you lose is a little work/time and a 30 dollar plastic spacer. Small price to pay for shutting me up. :grin: Not saying it will perform better than the stock intake, but it should improve your times over your previous testing setup without carb mods or 4 hole spacer. If I'm right...I won't gloat. I'll just be happy I could help. I don't know it all, but I'm no dummy either. I would like to know we all can help each other out. What it will also show is that the SP3 can improve ALL Buick 350's not just the radical ones. Wouldn't that be something? Gary
