Just for my use i dont know if i could justify the $300. But thank you its nice to know they handle long term use
What cc combustion chamber does the promaxx head have? What is the deck height of your pistons? What type of piston is it? What is the volume of the dish, dome or valve reliefs? You need to shoot for a quench distance of .035" to .045" to keep detonation at bay. Choose your head gasket thickness to keep this quench distance correct. That guide your are following is probably not the correct gasket. When using the aluminum head you can't use a thin shim gasket. I believe the recommended FelPro gasket for aluminum heads is .041". This puts you into having the block zero decked. If you don't pay attention to the quench distance, you will regret it when the motor pings and gets about 10 mpg.
It was a gm goodwrench crate engine, this build series did a lot of testing of parts using that block. http://www.superchevy.com/how-to/46438-gm-350-crate-engine-build-vi/ The block came as a very low compression motor originally. Here are the heads https://m.summitracing.com/parts/pmx-2169 The info i find online for the block are. 10067353 Brand New Goodwrench 350 Engine 1971-1985 Car and light Truck Replacement Engine. Engine consists of the following parts: Block -part # 10066034, casting # 10066036 2 piece rear main seal 4 bolt main Crankshaft- # 3932444 Nodular Iron 1985 and older flywheel bolt pattern. Powdered Metal Connecting rods- # 10108688 Cast Aluminum Pistons-#12514101 G.M. High Volume Pump Oil Pump- part # 12555284 Hydralic Flat tappet Camshaft- #14088839 Intake Lift-.383" Exhaust Lift-.401" Intake Duration @ .050"- 194 Exhaust Duration @.050"- 202 Lobe Seperation-112 This cam Has a mechanical Fuel Pump Lobe. This is a low end Torque oriented camshaft. Cylinder Heads- part # 14034808, casting #33417369, 1.94" Intake valve, 1.50" Exhaust Valve, 76cc Combustion Chamber, 7 Bolt style Exhaust Flange Standard, 85' and prior intake manifold bolt pattern. Perimeter bolt style Valve Covers. This head is very similar to the old #882 castings from the 1970's
I can keep up, even if i have to go back and read things again. This information is what im looking for and is helpful. Ive build many high hp motorcycles including building my 300+hp turbo hayabusa. I love learning and this gives me a lot to read up on while im at work tonight as i work 3rd!
Whether you choose to run roller tip rockers will be your choice but I will not agree that you don't need them. Over time a non roller tip rocker not only pushes the valve down but also pushes it side ways wearing the guide especially with extra lift. I had to replace guides in an engine I did race every 2 seasons and once I made roller rockers I have never had to replace them again. 25 years of racing. Cheap insurance and lower oil temp is an added plus.
Somehow I missed the fact that you had the aluminum heads. I would keep the guide plates but then the rockers need to be the early, non-guided, type. There is no need for the long slot rockers but if you will be changing rockers I would compare prices. If you could get a set of the stamped, long slot rockers cheaper than those Elgins then do it, it won't hurt a thing but again, the long slots aren't needed. Quench matters but to get a decent quench height you would really need to change the pistons. The pistons GM uses in the short block you have are four eyebrow with a sump in them to lower the compression. You will never have a real quench area with a piston that has a sump. A plus is the smaller 64 CC combustion chambers as compared to the 76 CC's that the factory heads would have had as you are picking up some compression. Definitely run the gaskets recommended for your heads and like you mentioned you will be checking for correct pushrod length. Some aftermarket heads do require a longer pushrod. One more thing about quench, in another thread I mentioned having pistons about .115 down in the bore. From what everyone tells me that is no good, but my set-up says otherwise. 2600 pound car, 350 SBC, 6-71 blower, two 600 Holleys, 4 spd. with a 3.36 gear and 31" tall tires and I get 17.5 mpg on the road
The head manufacturer doesnt have a listed head gasket was going to run the .015 gasket that the magazine build thread used. Eventually internals are going to be replaced and built into a 38e but i cannot afford that right now. Im about to purchase a house and,need to get this put together and drivable soon. The build they used with mstching combustion chamber size put it at 9.0:1 which will have to work for now. They do state it will take a longer push rod. Ideally if i can find a decent rocker for now and when i build the 383 in a couple years i can upgrade then but for now money is an issue
They will wind you up lol. You ask about rockers and now we're talking quench. You know the funny thing about a switch aluminum heads ,,,, It is all in the wording- some will say that you "can" run higher compression with aluminum heads- and that's true but misleading. For aluminum heads to net the same power levels as iron heads you "must" bump the compression up. Now That's just to break even, right? So you "can" run even another bump up with aluminum heads to realize a gain. If the build is planned for aluminum heads from the rip, well great. Make it all work and get the components to play nice. So about the only scenario that I can think of where a switch to aluminum heads is called for would be when your short block is on the money but your compression ratio is too high and the engine spends some time on the wrong side of that ragged edge of being safe for pump gas. A switch to aluminum head will solve a lot of troubles and net a gain. I see no reason to switch to aluminum heads on a stock entry level crate engine.
Motor will eventually become a 383 so it fixed the issue i had with studs,and preps me for my next step down the road
Things were a lot simpler when I didn't know any better. We used to run a claimer stock car class, 350 or 327 Chevy with double-hump heads. 30-30 cam with solid lifters and poly-locks on stock rocker arms. Twisted it up to 7K RPMs sometimes 2X a week for about 16 weeks of racing. Never had anything break, at least not in the engine.
Ignorance is always bliss lol, I loved when I didnt know any better and I just threw parts at things lol. Nice to know that they can take that kind of abuse. What is the difference performance wise and reliability wise of poly locks vs standard nuts?
The heads came in today and on the paperwork it states that the pushrods are 7.900" +.100 in most cases but recommended to verify with adjustable pushrods. So does that mean its a 8.000" pushrod?
Most aftermarket heads use .100" longer than stock valves to avoid coil bind with typical high lift cams. 7.800" is the stock pushrod length (in a non-roller cam engine). The engines I have built all used the 7.900" pushrods. Yours most likely needs the 7.900" pushrods.
Thank you i greatly appreciate it! I think i might buy one just to have as my father and i have a couple builds coming up in the next couple years and not a bad thing to have.
We always used the poly locks so they wouldn't back off and valve lash stayed where it was set. Sets for stamped rockers may be different than those for roller rockers. I don't see how we managed to buy all the right parts before the internets days! Just be careful with the push rod lengths, stock for a 350 Chevy is 7.794" (close enough to 7.800"). Most aftermarket aluminum heads use push rods that are .100" over stock, meaning 7.900". So get that 7.900 +.100 clarified. I've never seen it specified like that.
I still find that misleading, call their tech number. A checking push rod is still cheap insurance. I saw one guy take an old push rod, cut it in 2 pieces with an abrasive wheel. Then he threaded the inside on both ends, maybe used a 1/4-28 tap. Then used a piece of threaded rod between the 2 pieces... instant checker! I used a stock 7.794" push rod and I bought one 7.900" to verify the length. Here's a shot of the two patterns showing what worked for me.
First- I've never seen a lock nut come loose or be the cause of a problem on a hydraulic lifter in any engine that doesn't rev past 6500 rpms. At 6000-6500 Rpms something else will fail long before a lock nut. ****Even if by some chance the nut does experience an impossible harmonic force that does rotate it a smidgeon it's still friction locked every smidgeon of rotation. **** Polly locks are an absolute necessity for some roller rockers. the rocker body won't allow a nut and socket to fit within the rocker body so the shank of the poly-lock passes thru the rocker body. The adjustment is maintained and locked by just the itty bitty little set screw - unless you use a stud girdle. Second- I've seen plenty of poly locks come loose without a stud girdle. The internal treads are free not interference threads and just a smidgeon of movement releases the tension provided by the itty bitty set screw and the Poly lock is loose on those free threads to do the hooey dance. In my opinion the itty bitty set screw is enough to hold the adjustment sufficiently while the stud girdle is being installed. The RPM determines what parts are needed and 6-6500 seems to be the magic number where the quantum jump begins to happen if reliability is a concern. You see ,,,, most (not all) engines that regularly see 6500 plus Rpm and make serious power at that rpm are max effort specific and don't run very good in traffic. To realistically need and be able to use that amount of power you'd also need to have a competition based and accordingly built car.
Yeah... This is not any type of competition based car. Ive been looking at these rockers as someone pointed out speedway and whe i asked about these someone stated that they were good and,had good reviews. Any opinions? http://www.speedwaymotors.com/Small...ller-Tip-Rocker-Arms-1-5-1-3-8-Stud,6562.html
A good set of just locks alone will run you $80. WTF do you think you'll get for that set or tipped rockers and locks for 80? That claim of 30 Hp from roller tipped rockers is complete bullshit. Quality Hi tech valve train parts !!!!!
Scorpions are best bang for the $ USA made--we run them on alky injected vintage dragster--awesome quality for $222 a set on Egay 1.5 is all you need stay away from anything else--PRW stainless imported for $100 will stay put and do fine scorpions are killer quality for the $$$
http://www.northernautoparts.com/part/pf-66905 60.99... ya ya ya long slots, THAT are NOT needed, but its the NEW normal EVEN if ya dont need em.... with the swedged STOCK adj NUT( like the factory ) ...after all your(head) part number indicates you have the smaller OD springset 1.260's and so this WILL get you down the road UNTIL your FANCY 383 stroker UP-grade.(and then you can buy the BEST fancy rockers at a later date,when you've saved up for them) and now get your pushrod length FIGGERED out .
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