What do you think of this engine, and what do you think of this...

OK, here's my engine, I built this three years ago, with no end of fussiness and time wasting repetitive checking and rechecking (which saved me from an un-tightened rod bolt!):

1974 Buick 455 bored 0.030" over, had the block and heads magnafluxed, blah blah, they're sound, had the block align honed after it was bored, the mains were checked for straightness, and returned to straight, crank was checked, and sound, but undersized 0.020" on the mains, and 0.010" on the rod journals, fine, TA hooked me up with bearings.

Retained stock rods, which were checked by my machinist and given a clean bill of health

went with 10:1 forged pistons, and TA chrome moly rings. Alas, no notched pistons were available at the time (Mike was going to the nats and took em all with him, but he did call to say he was sorry I couldn't get notched pistons, which makes him a cool guy AND honest), new pins, of course.

retained stock pushrods, which were straight

retained stock rockers (1.55), but I do have TA roller rockers, ready to install

Stock smog heads, no port or polish, Fel Pro gaskets (never had one problem with the gaskets), TA undercut head studs

Stock AC Delco plugs, R45TS

stock valves, three way valve job (by a pro, not me, lol) done 4 years ago, about 22K miles total on the heads after rebuild, TA Stage 1 valve springs

TA RV12 cam, .440" lift intake and .468" exhaust, advertised duration 255* intake, 262* exhaust, 112* lobe center

new lifters (of course)

Double roller timing chain (one keyway)

Original timing cover, which I checked for tolerance and it was just OK, I plan on installing a variable pressure spring kit (I have the TA one) and a thrust plate

TA Headers, 1 7/8" primaries, 3 1/2 collectors, 2" exhaust

Edelbrock Performer 455 intake

Edelbrock 800 cfm performer carb, electric choke

factory ram air air cleaner and hood

Poston street/Strip HEI, 9mm spiral wires


I like this engine a LOT. This thing purrs like a...well, a kitten on Quaaludes. Honestly, you can't see the engine move when it's at idle. Very nice. It makes, I'd say, around 500 lb/ft, and 330 hp. Great, I love it. But, you know....I could always use more power. I am all but decided to buy TA's aluminum Stage 1 heads (I have 1100 of the dollars saved already, and I can save the rest I need for valves, etc, pretty quick). Here's the thing: if (when) I buy the Al heads, I'll want to swap out the cam. I've run the numbers through my desktop dyno, and the Stage 1 cam is a HUGE improvement. I am reading up on cams to see why, but desktop dyno is just a dyno simulator, I need real experienced opinions. my plans are to

1) put on the Al Stage 1 heads, with the roller rockers
2) swap in a more performance oriented cam. I like the Stage 1 because I really don't want to sacrifice the smooth idle of the stock-type cam. I'm not kidding when I say you could probably put a full champagne flute on my intake manifold and it wouldn't spill. I like that. Makes me feel I can do something mechanically when it runs that sweet.
3) rebuild my stock Q-jet as a winter project. I miss those secondaries
4) look into a better distributor. I like the Poston HEI, but I hear around these boards a guy named Dave can do much better for me in the distributor department

I've been pretty on my own up to this point with Buick engines, and at the risk of sounding smug, I'm doing OK, but like my info says, I'm a Buick newbie...since 1989. I know that compared to some of you, I know jack squat. This is why I'm asking your opinions of the engine I built, and what direction to take with it, with an eye toward retaining that silky smooth idle as much as I can, not losing all semblance of fuel economy (I get about 10 mpg round town and 14 on the highway- when I'm a good boy, that is), and keeping this '70 Skylark Custom convertible a daily summer driver. I have a TH350 that is (supposedly, I didn't do it, but it cost me 900 bucks so it MUST be good, right? lol) beefed up to handle the torque (I've had this tranny since '95, I installed the engine in '91, and I've had no tranny problems, and I sometimes drive, um, enthusiastically), and a Chevy 3.31:1 12 bolt posi. Thanks for any and all input, I'm pretty mechanically inclined and follow directions to the letter, I've built and installed this engine, installed the rear end and rear suspension, swapped out the bench and installed buckets, installed the top, rewired most of the car, done the bodywork and a billion or other minor things, I can reasonably perform any procedure you might suggest that isn't too crazy, and I have an indoor work/winter storage area that is big enough that I bult and installed my engine there, after removing all front end sheet metal. Thanks again in advance for any input.

 

Lots of looks, no replies...C'mon I can't bite ya, tell me your opinion! Is it good? Bad? Ugly?

 

Well I think you should take the lack of responses as a compliment. Typically if these guy's see ya making a mistake they'll step in.
I'm no more experienced than yourself, but the one thing that I didn't see you mention in the new department was getting the mutiple keyway timing set and degreeing the cam, with your desire to stay with a conservative cam (I'm the same way) and Jim Weise comments about how these new heads will work well with smaller cams I would guess that there's some free HP there. Then perhaps port match your intake to those fancy new heads.
Other than that I'm not sure what else I would do.
Sounds Great!
Len

 

Thanks, Len! Yeah, I suppose while I'm swapping cams, a multi key way is a good easy step to take.

 

Thanks, Len! Yeah, I suppose while I'm swapping cams, a multi key way is a good easy

After watching Gary's car run at Vegas, and you want a fully streetable, mild mannered motor but with get up and gotcha, ask Gary about his "little cam that could". That little sucker pull like a freight train all the way to 6K and beyond. Gary's car is fully streetable and he races planes at the air port, so it scoots.

Len

 

Well, since you want to keep that silky smooth idle, that rules out a lot of options. Basically you are going to have to look for free HP where-ever you can find it. You might try an 3 inch into 2.5 X-crossover exghaust system. That might free up a bit of power. A well thought out ram-air system(the factory setup is not very good)would help. If you are going to use the new ST1 alum. heads, that will give you a big boost with no difference in idle. About all I can think of right now.

 

Oh, I can sacrifice a bit of idle quality. I just don't want the engine shaking and my eyes rattling. I'd miss the idle I have, but if the idle didn't change too much for the worse and my power brakes don't suffer, I'm willing to consider a hotter cam. But I'm restricted on cam choices anyhoo, I don't have notched pistons. I'm looking at my TA catalog right now, and they have a "smooth idle" cam, just like they list my cam, at .470" intake, .483" exhaust, 260* advertised inatke duration and 262* exhaust with a 112* lobe center. That's similar to my cam, but a tad hotter, and from what little I know about cams, it seems this camshaft should give a similar idle to mine, especially with the same lobe center, right? The only difference is on the intake lift and duration. Anyone have experience with the TA 112 cam? How about anyone's experience with their TA 212, as a comparison? I can call them, but it's a three hour difference, it's easier to ask you guys, since most of you seem to know your stuff. Thanks again for all the input.

 

Chris,

Sounds like you're on the right track. Those 74 heads sound like the limiting factor right now. Big valves and smooth ports add up to nice flow numbers. If you run the air math for the improved heads on Dyno2000 you'll see what I mean...

What's your thoughts on changing to an SP-1 and holley 950? The simulator doesnt factor it in very well, but TA and TSP's dyno results show a real improvement in the SP-1. The holley will hurt your streetability, its a real sacrafice for power IMHO but if the Q-jet is dead anyways...

...I'm no expert, hope this helps!

 

Hmmm, SP-1....I dunno, the heads are 1300, the valves are about 300, the cam is about 300, I don't know if I can spare 2 grand this close to the holidays. It's definitely a thought to consider.
I ran the flow numbers for the al ST1 heads and:jd: The engine picked up over 100 hp, with no other changes. That's just a sim, but still

 

Q jet

It looks like you are going to replace the Edelbrock with the Rochester, right? You said it is stock, does that mean it is a 1974 carb? If so, thats good as it is an 800CFM. Check the number to be sure.

Also, there are a number of mods you can make on it in addition to a rebuild. Some builders have great reputations (John, Norm, etc) and build a carb that starts/idles great even with a mild cam.

Giving it to an experienced rebuiilder may help you there, cost is usually around $250 with your core.

455 like big carbs. With your new heads you may want to think about bigger, although it will cost you more MPG!

Also, look at your fuel flow. Is your pump stock or stage 1? or electric?

Also play with your timing. You can go more than stock and your engine might like it!

Let us know what works! :TU: - Bill

 

Options

Chris, with the new heads vs. your 74 irons, look carfully at the combustion chamber size. The 74 heads are low compression heads with large volume chambers. I don't know the chamber size of the aluminum heads but I'm sure it is less than the iron heads. What this means is your compression may go up.

You can get away with a larger cam as your compression goes up. It will retain good idle quality with a larger cam.

I have a high compression 430 and am running a cam more radical then TA112 but same lobe spacing. I can hardly tell I have a cam in it at idle until I hit it.

Just more for you to consider and get more confused.

Good Luck.

 

Well, the combustion chambers should be smaller, so I expect more compression. I also understand that the gasket thickness and the diameter of the holes for the cylinders come into play here, naturally, the distance away from the block influences the ratio, but what about the diameter of the cylinder holes in the gasket? How does that relationship work?

I am seriously considering a larger cam, but I'm going to get any info I can before I make my decision. I really would like to here someone tell me about their cam's specs, how it runs, and the idle quality. That bit about the 430's cam is exactly what I'm looking for Glideman, thanks.

Also, I see that some people here would rather eat worms than run AC Delco plugs at 0.40" gap in their 455. Any input on the plugs and gap?



Bill- the Q jet is a '74 unit. The pump is (I beleive, I'll have to pull my receipts and look, I put it in three years ago) a Stage 1 unit, because my local parts place's supplier superceded the non stage 1 pump with the Stage 1 pump, since they both bolt up the same.

My distributor's spec sheet recommended 13 degrees, I timed her at almost 15, it ran a bit better and pulled steadier Hg (18" or just a mite over, pretty dern steady). I need to locate a new timing mark...what's the distance to go, 1.675"?? I think I might forget now.

thanks

 

I have the ta 112 in my engine to me it seems weak in comparison to my worn out stock 1971 electra cam. You would think after adding the edelbrock performer intake the matched 750cfm performer carb and a .30 overbore that you'd gain hp. I don't know what went wrong but it doesn't have the torque on the highway it used to have. I expected a feelable gain of 30hp. I am going to have to do a little tuning on it I have no idea what to set the timing at but the engine sounds very very much stock just has a more deep breathy sound on the highway (probably the new intake.) I'm looking for suggestions on getting the ta112 to be the 20hp gain it claims to be. I have timing set to 34-36 is that too low for it maybe?

 

I had forgotten about this thread!

The first thing to do is the get a larger cfm carb, in my opinion. The intake charge velocity of a Buick 455 is such that it benefits from large cfm carbs- the stock carb on a high performance 455 was a 800 cfm unit. I used a 750 cfm carb (Edelbrock Performer/AFB clone) and when I switched to a similar carb but at 800 cfm, I felt an immediate increase in power. I am not a fan of the edelbrock carbs anymore, at least their AFB clones. I have fuel slosh issues from the side hung bowls, and the engine just doesn't give me the kick in the pants that the stock 800 cfm Q-jet did. I'm sure the acceleration is almost the same, but the Q-Jet sure did make the car feel quicker. The common wisdom that the dangers of over-carbing an engine is easy to do doesn't hold as true for the Buick 455 as other large cube engines. There's even a formula around that "determines" the correct cfm, and for a similar cube engine from say, Chevy, the "correct" cfm is around 750- but that's pretty much proven to be too little carb for the Buick 455. there's a good reason the stock cfm went up to 800. The racers here use 1000 cfm Thermoquads in many cases. My buddy has an 850 cfm T-Q that he is going to lend me. I'll see what I can see...

The total advance seems about right, but it also matters where that advance comes in. Also from what I hear, TA recommends a 4* advance install on many of their cams. Have you talked to anyone over there? They seem legitimately concerned that your Buick runs strong (translation: they want their company to have a rep for making high perfromance stuff that kicks butt)

I'm all but decided that I'm going with a TA 212. I make almost 20" Hg now, and the engine idles smooth as silk. I can easily give up some idle quality and vacuum:TU:

 

Well I figured out the problem i'm an idiot I had it way overadvanced. It was set to like 35*... with 10*advance it runs alot better. According to what TA says on the cam sheet I somehow came up with 9.5* advance over stock advance which is 4* on most buick 455's so I guess that means max advance for performance with this cam would be 13.5*? It managed a 20 foot burnout but still I swear it's a huge engine no matter how heavy the car is I say it should be as good as that 350 that can manage to burn until letting off the gas, with the setup i'm using. Let me bore whoever doesn't care about this and see who can answer this question this is word for word from the ta cam instructions.

.....In most applications the cam is run at 2 to 6 degrees advanced. To advance cam timing add the amount of advance to the opening figures. Subtract equal amount from the closing figures.....

Whats the opening and closing figures? I have on this sheet exaust opens 40.5* and intake closes @ 37* these are what I used to get 13.5*

 

Is this the engine that came with the car, or is it an engine swap? You mention the 350, so I'm curious. If the car had the engine swap: Perhaps one problem is that your tranny kickdown is set for the 350's specs, and you're shifting at the wrong point.

Another problem is that I really feel you're strangling the engine with that 750 cfm carb. Plus it's a generic application carb, not one tuned for the engine.

 

No it's the original 455 electra engine. The 750cfm performer matches the performer intake and was a great improvement over the QJ because The QJ never worked after 2 rebuilds I got pissed at it and threw it to the side of the garage and bought the 750 it made a great improvement from what it was running like.

 

That's exactly why I bought my 750 Edelbrock. Try an 800 cfm unit. If all goes well, I might be selling mine, but probably not until next spring.
Check your float levels, and see if you can benefit from a different setting on the accelerator pump. Another thing to consider is your metering rods- it's almost a given that out of the box, that 750 isn't optimised for your engine. Get a strip kit and borrow a G-Tech or go to the track and do some tests, is all I can suggest. Start off with two steps richer on the secondaries, in my opinion. Exhaust is another consideration, and one that I do not pretend to fully understand yet- I got a 2.5" exhaust and no appreciable power gain- because my carb is now jetted wrong, considering the exhuastou:

 

Ok I figured it out do this get the ta 112 and set it to 13 degree's with the vaccum advance disconnected it should read 13 or so on the timing tape from ta. It's got the power now man.

 

:TU: