Piston and cam choice for 455 build - Done! Now with parts list Rebuilding the engine for my '73 Riv. Looking for good power and streetability. I'll be putting '71 heads on a '74 block and expect the bores to get opened up. The heads and deck may get surfaced and brought true but I won't be cutting them to increase compression. I would like to boost the CR using higher CR pistons. Looking for use a stock '71 intake with a classic Quardrajet. Might go Performer on the intake. I'm planning to keep the valve train stock with hydraulic lifters and stock springs. Doing a full rebuild otherwise. Crank is back with 0.010 off rods and mains. I'm wondering about the piston and cam combination. I'm leaning towards Speed Pro H392NCP hyper pistons and a TA C113 (.472/.476) or TA 284-88H cam (.459/.470). Maybe the TA 1607 cast pistons in 10:1. What do you think about these combinations? What I'm having the toughest time with is determining if the cams are too tall for the pistons. Any idea how much lift is possible with the Speed Pro or TA pistons? Thanks!
If you are going to use a Hypereutectic piston, go with the Keith Black KB357-030. Yes it cost more than the Speed Pro but for a good reason. The KBs have a 2 valve reliefs and a stepped area for good quench. They also have a higher compression height (2.010) so you only have to take about .010" off the block deck to get zero piston to deck clearance. The quench distance will be the head gasket thickness or .038" to .040" which is good. There is more volume in the KB step than in the Speed Pro dish (26.7cc versus 23cc). The KB will give you 9.9:1 compression ratio at zero deck. The KBs are set up for either a press fit or floating pin. This doesn't matter to you at this point. The KB piston crowns are held to a much closer tolerance than the Speed Pro. It didn't use to be that way until Speed Pro started manufacturing out of India. The KBs are heat treated to T6. There is a lot more in the way of comparison.. Both of the cams you chose give a dynamic compression ratio just under 8:1 with 10:1 static compression ratio. You did your homework. However for good street manners for a heavy car it is better to have a cam with valve overlap near 0 degrees and a lot of low end torque. Normally the recommended cam is the TA212 but the compression ratio is limited to 9.5:1 with iron heads. The other consideration is; for a wide power band using stock heads you want a big split between intake and exhaust duration, 10 degrees or more. Pistons that have valve reliefs cut in the heads will not have a problem with valve clearance with the range of cams you will be looking at but it is always good to check valve to piston clearance anyway. What do you consider good streetability as far as idle quality and rpm, gas mileage and what transmission and torque converter? Paul
Thanks for the great info, Paul. The car will retain the TH400 and I've thought to replace the torque convertor. 2500 or 3000 stall for that. Gas mileage is not important. As it gets driven around the city it needs to idle well but it doesn't need to be "smooth." I can turn the idle up if it tends to stall out. 800 RPM good. 1200 OK.
I think your limiting factor will be the stock springs. There is a huge difference between your two cam choices. If you are set on stock springs I think the TA 212 would be your best choice. Seriously consider a mild spring upgrade and your cam choice will open up. It's best to check with TA
Glen The TA C113 fits your criteria. It is a strong cam that comes on smoothly. With 11.5 degrees of overlap the idle will be lopey. If you set your timing correctly and adjust the carb for max vacuum at an idle there will be plenty of vacuum for power brakes. DrBuick is right about valve springs. When you get your cam, the cam card will specify the needed spring. It will probably be the stage one spring. You can call TA and they will tell you what spring you will need so you can set up your head. Will you be doing the engine assembly? Paul
Sure. I try to figure things out as I might get things from different vendors. Not sure. I've done a few engines and a bunch of heads. I might have a shop build the short block if it's bored. I'll be doing the heads and the rest for sure. ---------- Post added at 12:48 PM ---------- Previous post was at 12:38 PM ---------- I wanted a bit more than the TA 212. I'll have several sets of springs and rockers soon. Thought to pick out good ones and not get new. New lifters and maybe push rods. Will stiffer springs require freshening or upgrading the rocker arms and shafts?
The C113 cam will need the Stage 1 springs. Stock springs are 80 lbs @ 1.860 and 220 @1.360 or .500 valve lift. The Stage 1 springs are 100 and 315 lbs at the same heights. You will want to have the rocker arms and shafts in good shape as part of the rebuild no matter what the cam and spring choice is. The original style rocker arms and shafts will work fine as long as they are in good shape. You will need new lifters to brake in with the new cam. The old pushrods should be fine. Paul
Thanks again, Paul. So I'm looking for springs now. I see Comp Cams offers springs almost that stiff. Any thoughts on the KB hyper pistons versus TA 1607 cast in 10:1?
The KB hyper offers a lot more quench than the 1607 round dish. The hyper piston can be set up with a little tighter piston clearance than the regular cast. The KB hyper piston has a lot more silicon in the aluminum alloy than the regular cast which makes it harder for better wear resistance and gives it better control over the expansion rate as it heats for tighter cylinder wall to piston clearance. The down side of a hyper is that a high silicon alloy is more brittle and once a fracture begins it will continue to crack (like glass) until the piston fails. It means that it will not tolorate detonation very well and the tune-up must be right. Not recommended for high stress racing applications. Lots of hypers have gone millions of miles without failure. Paul
I have basically the the same build for an all iron build except my worked 280/190 73 heads (w/stg1 valves) and have been shaved .030" and the block trued up and has a .020 deck height. I bought 1 new 2353 speed pro forged piston (w/skirt coating) to complete a set of seven older 2362's I had. The new one had a 24cc dish (was stated to have 27.8) compared to the 23.5 for the 2362's. Compression height was 1.975". I used the poston gs113 cam 228*/246* @.050" (basically the same as the TA C113) w/1.6 Kenne Bell roller rockers. I had tons of room so notches were not needed. Installed on a 108" c/l the dcr was 7.69 and static 9.9/1 (w/.039" head gaskets). Will be used with a 2800 stall & 3.42 rear. It's assembled and will soon be fired up. Ray
Thanks, guys. The engine is at the shop now. I'll be giving those KB pistons a good look once the mechanic weighs-in.
The engine is all together now and I've got time to follow-up. Here's the parts list for the 1974 block: TA Perf TA_290-94H camshaft TA Perf TA_1607 pistons in 10:1 and 0.030 over Hastings Moly piston rings TA_1636 Comp Cams valve springs 249-910-16 SEALED POWER Rod bearings 3320CP 0.010" Undersize CLEVITE Main bearings MS908P 0.010" Undersize CLEVITE Cam bearings SH1361S Reinz gasket kit 953009VR ANCHOR Motor mounts 2291 SEALED POWER Valve lifters HT969 FEL-PRO Valley pan MS96005 AUTOTEMP Water outlet W1494 GATES thermostat 33009 COMP Cams 7896-16 Pushrods Sealed Power oil pump kit 224-519 TA Perf Head studs 1134 TA Perf Main studs 1120 Sealed Power freeze plug kit 3818003 Stainless fastener kit off eBay Poston valve covers 1970 Heads shaved 0.020" with stock valves Stock 1971 intake manifold Stock 1973 Q-jet HEI Distributor from '74 Electra Machine shop: Crank undersized 0.010" all all journals Block overbored 0.30" and decked 0.010" to 0.020" Heads cut 0.020" with new stock valve vale and guides Might have forgotten something or gotten a number or three wrong. And I threw in a rebuilt steering gear, too. Didn't total up the money. The good news is that it starts and runs. The pistons don't touch the valves which was my main concern going with a bigger cam, taller pistons and head and block work. Had it working back in December and its break-in run was to storage. I've had it out a few times and am getting it tuned up. Having some issues getting the timing set right and the carb tuned. The bad is that there's some odd rhythmic noise. Not coming from anywhere specific that I can tell. Might be a rod touching the oil pan. Might be some exhaust leak. Not really a sharp metal-smacking-metal noise. Could be something scraping. It sounds loudly at idle but doesn't get worse with speed, just faster. I'll probably need to pull it this spring. Until then I'll be trying to make it idle better.
That cam should be idling pretty nice. Some lope but not too bad. Rpm might drop a good bit when you put it into gear if you still have the factory converter. Not a bad list. The car should run good. Only a few things jump out but nothing that is critical. The heads studs are overkill. No problem there but if you ever have to take a head off in the car, oh boy. I would have added a Sealed Power oil pump thrust plate but if you have good oil pressure then you are ok. The pushrods could be a bit too long causing too much preload with the head and deck milling and the TA cam could change the preload also, for good or bad. Adjustable pushrods are recommended if the preload measures out too much or the car won't rev above 5000 rpm or so. If you can get a video of the engine running with the noise it might be easier to figure out.
Hi Glen, did you modify the timing advance curve? If not you might want to read Larry's Power timing thread... http://www.v8buick.com/showthread.php?63475-Power-Timing-your-Buick-V8
Thanks. Already been there! I want to try changing the vacuum port that I'm using for the vacuum can. Right now I'm using ported vacuum (Right or pass. side of carb, mid-way up) and want to swap to a non-ported source (left or driver side at the bottom). Maybe that'll give better vacuum. The problem now is that it needs to idle fairly high and when I put it into gear it stumbles and dies. Seems the vacuum goes too low with lower RPMs and then the car runs poorly lowering vacuum further so it dies. I haven't put a tach on it yet. I did triple-check the timing between crank and cam. I re-used a recently-changed timing chain so a touch of slop but it's not off a tooth. What I'm looking at as a solution is to increase the static advance and reduce the mechanical and vacuum advances. Looks like I can do that with off-the-shelf kits.
You don't want to use non-ported vacuum for advance to try to get the car to idle correctly. You have said it youself, it changes too much when the idle speed changes and then rpm drops and then vacuum drops and advance drops, stall. It is a vicious cycle. It just makes it worse. You are right about the advance. NO vacuum, less mechanical advance, and more initial advance is what you want. 16-18 initial and 32-34 total. That cam should idle pretty good at 8-900 rpm. A big stock 13" T-400 converter will have a very low stall speed and really drag the rpm down when put into gear. What converter do you have? Ported vacuum should not have any vacuum at it when the car is idling. If it does it means the throttle blades are open too far exposing the port. That is not correct at idle. Disconnect and plug the vaccum advance ports completely and then get the car to idle. Vacuum advance is secondary after the idle is corrected. If you have to have the idle speed screw turned in too far maybe some 1/8" holes drilled into the back half of the primary throttle blades will allow you to back out the throttle screw to allow the throttle blades to be in their proper position.
Just curious.... was the intake milled to match the milling of the block and heads? If not you should do that and see if it makes a diff. Also, with the metal valley pan gasket you will need to retorque the intake after the fisrt couple of heat cycles. If you have not retorqued the intake then you will be amazed at how loose the bolts are. That could be your problem right there.
Whenever we install a cam similar or more radical than yours,I always disconnect the vacuum advance and run just mechanical.its a lot easier to get timing and advance curve set so that idle and idle in gear can be established.The weights in the distributor react more consistently also. Gary
