pparaska Posted July 14, 2001 Share Posted July 14, 2001 No, the dome is not across the entire piston top. At the quench side of the chamber you'd have a huge cavity at TDC. Can't do it that way. IF you really want this engine to sing to 7000+ rpm, use longer rods and shorter custom light pistons. If you can stay below that area of rpm, I'd just go with the stock parts (pistons) for the 302. Quote Link to comment Share on other sites More sharing options...
Guest Night_rider_383 Posted July 14, 2001 Share Posted July 14, 2001 Montara22... No prob man. Yeah we are all here to help each other and catch what the other guy missed right. Speedracer... Yeah that 4'' bore needed for 2.02'' valves really goes more for oem heads cause of the shape of the chambers but in some cases also goes for aftermarket. Now I aint checked with trick flow but in summit page 20 they list the trick flow 23 deg. alum. heads 2.02/1.60 valves and under all part numbers no matter of year of engine pre 87, 87-95 ect. They only list the 4.00''or larger bore engines 327-350-400. Now summit may have to picked the most used engines to list cause they did leave out the 302. World s/r torquers 2.02'' valves list fits 302-327-350-400. Then alot of the other heads such as dart just has fits small block chevys so i guess if the chambers is in enough of a heart shape then it wil give you the needed rome on a smaller bore engine to fit 2.02 intakes Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 14, 2001 Share Posted July 14, 2001 im gonna call around today and see what im looking at for pistons, im almost to the point where theres too many good heads for the 4" bore, and not use them. we'll there be too much torque from a 302 for a t5 to handle? also i read about this aftermarket part that bolts to the rear of a t5 to increase strength? anyone seen it? not planning powershifting often but would like to be in the safe zone. thanks Dan Quote Link to comment Share on other sites More sharing options...
SpeedRacer Posted July 14, 2001 Share Posted July 14, 2001 Here is a quote copied right from Trick Flows own web page "TFS-30400001 TrickFlow 23 degree cylinder heads for small block Chevy." "The fully assembled heads feature 2.02 in./1.60 in. stainless steel valves, premium 1.25 in. diameter valve springs, locks, retainers, studs, and guideplates. The heads also have hardened exhaust valve seats for use with unleaded pump gas." "California Air Resources Board Executive Order #D-369-4 for Trick Flow Specialties 23 Degree Aluminum Cylinder Heads for 262-400 c.i.d. Chevrolet Gasoline Engines, Part Numbers TFS-30400001" And yes Lone, I belive it's the slightly off center stagger of the valves and slight angle of the vavles that allows them to clear the cylinder walls on a smaller than 4.00" bore. I just though some of you with smaller bores might be interested to know that there is an aluminum head that you can use. I have these heads on my car and they are really nice but I didn't do a before and after dyno run so I can't tell you how much power I picked up. I will tell you that I am at 10.6:1 compression and I do not have any problem with pre-ignition on good 93 octane gas. Also, I do not have a 302 but a 327 and have never taken it over 7,000 RPM. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 15, 2001 Share Posted July 15, 2001 My Dad Built a 302 that won 2 world records at Bristol Dragway, held one for 6 months too. Definately a screamer. I Luuv low end grunt myself, Don't have to change gears as much...but I'm starting to think that alot of it's wasted on a car as light as ours. What do you think about a 10.25 compression 302 with a Holley Strip dominator and 650 cfm for everyday driving? WW∞ Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted July 15, 2001 Share Posted July 15, 2001 quote: Originally posted by 283z: also in regards to the intake volume i had a question for you.. why would such a large volume intake port (190-210cc) be required to get 375 hp out of a 302 if you can get 420 hp with the edelbrock rpm heads on a 350 when the rpm heads only use a 170 cc tract? just wondering... 283z, To answer your question about the power a 350 makes -vs- the power a 283 or 302 makes w/the identical cyl.heads. It has to do w/displacement; more specifically-displacement per cylinder! Upon one full swept volume (Piston moving from TDC to BDC) of one cylinder a 283 has 35.37 cubes to play with while a 302 has 37.75 cubes and a 350 has 43.75 cu.in's to play with...the 350 has considerable more cubes which allows it to reach peak power much easier. The smaller displacements have to kind of [work their way up to peak power]. Anyone ever heard those stories of "I have this friend w/money out the wazoo & everytime some new Hipo engine part hits the streets-he's the first to buy it & the other day he purchased & installed the largest cyl.heads on his engine they made-he thought he'ld improve his engine.....only to find out his engine is now a dog?" This story is heard all the time & its because the guy didnt consider the basics of an engine; that being an engine is an air pump! That's why you have to consider the Port Velocity, Port Pressure & the Density of the air w/in the ports if you can control it as well as the factors that control these peremters. That is also why you cant just start swapping cyl.heads from one displacement to another & hope for good things to happen; you have to match your components to each other for a specific goal. On a Cyl.Head you have to consider the Intake Port Entry Area, Intake Port cc's, Valve Area, Combustion Chamber cc's & Exhaust Port cc's; all these dynamics will work w/the camshaft to make or brake your performance as they directly effect the characteristics of the air w/in them. If you're going to build an engine it should be built around the camshaft & work your way outward. I agree w/Pete on the piston pop-up's. You can't measure pop-up's like you can flat tops. The pop-up's are not even all the way around. The dome measurement is on top of the piston comp.height but that measurement doesnt automatically translate into an easy formula for determining its dome cc's-how much is it taking away from the combustion chamber in cc's is something you'll have to perform when you cc the piston w/in the cyl.bore. IMO: I'ld prefer to use a 6" rod if one could get away w/it. Timing would be that much better; IMHO. Kevin, (Yea,Still an Inliner) Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 15, 2001 Share Posted July 15, 2001 Displacement is definitely a factor in comparison. But stroke is still a powerband deciding point. The shorter the stroke, the more RPM and the low end torque will go away. Longer stroke less RPM and more bottom and mid-range torque. It depends on what you like I guess. I personally don't see a need to spin a V8 to 7k or more, its just not necessary IMO on a street driven car light or otherwise. I do like how quickly a small stroke motor winds, but I think calling it halts at 6 or 6.5k is sufficient in a Z. Spinning it higher cost more to construct and for what, most of the torque has already subsided and your reving it for no reason. Its all a personal preference, we've rehashed it all before and it comes down IMHO to what you like. Good luck with your project, Lone Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 15, 2001 Share Posted July 15, 2001 Thanks, i just emailed trickflow to see what they have to say about it. Quote Link to comment Share on other sites More sharing options...
fl327 Posted July 15, 2001 Share Posted July 15, 2001 hey you guys are describing me to a T! ive got a 1967 small journal with (lord love em) camel hump 2.02 heads, and its wonderful, i do need to bump up the cam and do a little something something to fresh him up, but hes running really strong with 650dp. my power band is limited by manifold and cam to about 6k, but from 3-6k its all love baby.... im really in love with dz motor, and would love to get a hold of one of those but ive got the 327, and it aint broke.. loves to rev, and torque isnt an issue this motor makes maximum torque at 3200, and keeps around that zone until about 5700 from what i can feel in the car, with some love i want this guy to spin up to about 7k+!!! Leonard "it feels like vtec" Quote Link to comment Share on other sites More sharing options...
Guest Night_rider_383 Posted July 15, 2001 Share Posted July 15, 2001 FAIRLADY 327.... sounds like a nice one bud. I like these small journal short stroke engines. My streeter Is a 62 327 stock forged crank and rod, rods resized and arp bolts added, trw .030'' over forged flat tops, 9.78:1 c/r, 1965 327 double hump heads, ported, manley 1.94/1.50'' valves, k-motion springs, cranepower max 272/284 cam 216/228 @.050 .454''/.480 lift, roller 1.6 rockers brings lift to 484''/.512'', performer intake, 1'' spacer plate, 600 cfm edelbrock carb, gm hei re curved, this thing has 453 hp and was built to spin up, but even down low it has enough torque with a 3.07 gear and a 2800 stall to light up 29''X10'' street tires in a 4700 lbs truck for about 75-100 feet. I take this engine to 6300 rpm at the track but on the street its never been past 5100 never needed too lol. These engines is fun to drive thats for sure Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 16, 2001 Share Posted July 16, 2001 7k is definitely higher than i think ill ever need to spin this engine. a constant build from 2500 to 6250 maybe 6500 would be ideal. big torque complicates a lot of things i.e.-tranny, structure, needing huge tires which means expensive rims. as ive said before IMO 300 hp should be PLENTY sufficient for a 2400 lb car especially one with 411 gears! and even though a 302 may be short on torque, compare it to a l series and it looks real good! also makes hooking up easier! i guess my big comparison would have to be an NSX it weighs over 3k lbs 290 hp and like 220 ft-lbs torque it runs the quater in like 13.2! ! i guess i use those figures as a good benchmark to beat. ! time shall tell! and btw thanks kevin for that explanation makes sense now Dan Quote Link to comment Share on other sites More sharing options...
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