So...I got a set of '69 430 heads on my 455 block, plan on installing stage 1 valves, stock steel rocker, stock rod, looking for 9.5 - 10.0 to 1 comp. Do I deck the block, mill the heads. I like what I read about the TA 290-08H cam. If I run this combo, what pistons and do they need to be notched. Also what stall tc or switch pitch to run with this cam. Plan on SP1 w/800qjet headers got 3.73 gear 90 percent street, but, just a toy, not a daily driver. Thanks
Jamie, I would go with a Switch pitch or maybe a 2800 stall converter. I have a 90% street toy `72 Skylark. I am running the 413 cam, 10.5:1 and 3.42 gears. I have tried both a 3200 and a 2800 stall converters. I'm not sure which I like more but I really like the 3.42 gear for the street. With 3.73 gears and a 3200 stall you will have a tuff time hooking on street tires (or anywhere else). A lower stall (2800) will help you hook before your engine gets to peak torque and getting a good start will be easier (in my opinion). :TU:
Hi, I'm running '67 430 heads on my 455. They have Stage 1 valves and have been ported. Block is zero decked to .003 and pistons/combustion chambers polished. My cam is Poston's 113A cam. My true compression is 10.13 to 1. I run TRW pistons with stock rods and crank. Intake is a SP1 and a Holley 950HP. I have no detonation problems at all running 93 or 94 octane. But I did before the polishing job. Definitely worth the time, unless you like buying racing 110 fuel. My car is 90% street driven about 5000 miles a year. Pistons should not have to be notched as long as you run the cam straight up. Make sure you degree your cam in. I didn't at first. It ran .1 quicker and 2 mph faster after properly degreeing it in. Originally, it was installed "straight up". I run a 3.73 rear and a 3300 rpm stall in my th400. Hooking up on the street is impossible, and I have 325/50 DragRadials on the car for the street. I have to use slicks on the track or I'd be spinning a good part of the way. I would have to agree to stick with a 2800 or so stall and possibly a 3.08 to 3.42 gear. You'll still need a good set of tires to hook up. But this will give you solid mid-12's or so, and you'll be able to cruise down the highway at around 2500 or so. I believe you can fit a 255/60 tire on the with no problems at all on a 15x7 rim. I'm actually going to be putting in a 2.73 posi rear in my car next spring........after Norwalk. 70 mph will be about 2250 rpm's. This is with 28" tall tires.
Sounds like this combo would be too hard to hook with my 255/60 already on the car unless I run a convertor in the 2800 or less zone. So, the switch pitch might be more of a chore to drive than fun on the street. Right? How far up can I expect the power to come in. Currently running KB118 w/2300 stall, but, the trans is at the trans shop right now, so, need to give him an answer on what convertor I'm going to use. I'm expecting a big HP differance and don't want it too low causing it to just lay there until it gets up to the power range. As far a notching, just called TA and they said anything above .500 lift they would like to see notches. Didn't say anything about duration and I told him what cam I wanted. The question I have is, have any of you guys tried this and measured the piston to valve clearance with clay? It would be nice to save a few bucks and not notch. Trying not to put an engine together twice because the valves get too close. I saw a different thread on piston selection and someone said summit had the pistons at a better price than ta. But, then if I need notch's, I gotta take my pistons to ta and have them notched. Would like to just go ahead and buy pistons from ta in the first place if I need notches. Cast pistons are alot cheaper, but, not reccomended above 450hp, I'm hoping to get close to 500, maybe dreaming.
When I had my engine mocked up, I believe I had about .200 clearance with TRW pistons, zero-decked block and heads trued up. I think most like to see a minimum of .125. Every engine is a little different. Might be worth mocking one side up and checking it. Phil
Valve clearance All I can say is I had much more valve clearance than I thought I would with my `73 BBB. I decked the block (a lot) so the pistons were at zero and machined the heads at least .030" and ended up with 69cc chanbers (removed bump). My final CR ratio ended up close to 10.4:1. I was worried that my dynamic compression was too high so I picked the 413 because of it's late IVC. So, I polished the chambers and Hyper pistons (I did not want detionation). Due to my underdrive pullies I have reached 235 degrees after a traffic jam and a dreaded five minute heat soak. I have never had any detionation problems with 24 degrees initial and 34 degrees total. My intake valve clearance was .350" and .330" exhaust with the standard valve cut-outs of the Hypers. The 413 cam is at 107 ICL as well. This is just another data point that may help you in your combination. You may be o.k with valve clearance but always check first, and yes duration and cam timing must be considered, it's more of a factor than lift.
Re: Valve clearance Cut-out's, you mean what how the pistons came in the box, w/ no add'l notch cut into them? Sounds like I shouldn't have any problem then. Look's like the 413 is pretty close to the TA 290-08H. Don't worry, I will mock up and check. Just want as much info before I start ordering parts. Thanks
I have a set of the hypereutectics for sale, if you're interested. Poston sells them for $289 new. These were put in a new motor, which was never installed in a car. These look like brand new! I will have to see if the rods are still attached, and if they have been reconditioned. I can then give you a price for the pistons with or without rods (I need to talk to my dad- he has them at his house). Let me know if you're interested.
Jamie, I did not buy these pistons new, they came with the engine I purchased. The Hyper pistons have 26cc's volume, use this infor. to help you calculate your real CR. The Hypers are decent pistons, at a good price. Make sure your combination is set up properly (fuel, timing, quench, dynamic CR, temperature) and you should have no problems up to the ~480 HP range (my opinion). If you want 500HP or want to run 11's or you're going to spray it... go with a forged piston. I'm running 12.6's at the track with TA radials and am sure there's a 12.0 there with some tuning and tires. I don't plan on installing a roll cage so sub 12 sec. slips are not the goal.
Yes, I am interested in the pistons only. My rod should be just fine. I assum they are the same piston Craig is refering to?
I would stay away from the hypers for a performance engine. Some people have luck with them some loose the ring lands. One things for sure if you go with the speed pro forged piston you will pay another $150 bucks or so but you get a great piston. The full dish piston that we use is not a squish piston. Only the outer 1/4 inch or so. A bathtub dish is ideal for zero decking the block to control detonation.
JamieG, Yes, they are the same ones Craig is referring to. I agree with what Stage2man said. If you're looking for a high performance buildup, don't take the chance with these. If you are careful, and do everything to minimize detonation, they should work fine for a moderate buildup. A lot of people have used them successfully. To be completely honest, even though I am in the process of gathering parts to build an engine, I didn't want the risk. That is why I am selling them. So, it's your choice. I still have to talk to my dad and see if the rods are pressed on still. Craig definitely did the right thing by polishing the tops. It looks like he did a lot of smoothing on the valve cutouts too. My only question would be what will happen when there is some carbon buildup on the engine.
Thanks for the input. I have alway's leaned to the forged side, but, the price diff is fairly big and makes a guy wonder. I guess if I plan on running that much cam w/ ported head, I plan on a hi-po build. Still leaning to the VP convertor also, got pwr brakes.
The price difference is big, but compare it to how much you will have in gaskets, bearings, machine work, and all the other stuff it takes to do a rebuild, and you will see the price difference doesn't amount to much of anything. I wouldn't go with the VP converter (I'm assuming you mean variable pitch, as in switch pitch). They don't multiply torque like a fixed converter. I would run a good fixed pitch unit- probably 3500 stall for the 290-08h cam. Don't skimp on the converter or you will be replacing it. I have seen guys spend more on multiple cheap converters than they would have if they went out and got the right one in the first place. ATI treemaster is a good converter.
