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Post by Andrew on Oct 2, 2006 23:24:34 GMT -5
I need help on deciding whether or not to stay with my current Twisted wedge G1 heads. My current combo is 355 chevy with a gm steel crank. It has trw forged flat top pistons compression is supposed to be 10.5/1. It has a small lunati solid roller cam. I was told by the previous owner that the specs on the cam are 245 @.050 on duration and 554 564 lift. It has a Weiand team g intake with a BLP 650 holley that flows 770 cfm. Lastly 1 5/8'' headers. This is in a 80' malibu with a t-350 at about 3200 lbs with me in it. It runs consistant 12.30s at 108. I bought this car with the motor already in it. The bracket season is over and were going to freshen the motor and put a better rods in it. Im hoping just to hone it and use the same pistons without a bore for budget reasons. My goal for next year is to run 11.70s. I'm trying to determine whether or not to have these heads ported by cfm or go to a better head. Are these heads capable of getting me to my goal. I also have thought about angle milling these heads to increase compression to 11.1 but I been to told there could be pv clearance issues. I have also considered a slightly larger roller cam but have been told once again there are clearance issues. Any advice would be appreciated.
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Post by 67RS502 on Oct 4, 2006 11:41:24 GMT -5
I've seen 350 in a 3000lbs camaro go low 11s with these heads with a 224cam.  I'd keep the heads, just port them, should be good for high 10s at 3200lbs with these. |
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Post by BrianB on Oct 11, 2006 0:05:08 GMT -5
Do the twisted wedge heads require a special piston?
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Post by Ron Miller on Oct 11, 2006 8:51:13 GMT -5
With my past experience on small block Chevy's is that they like more gear and at least 1 3/4 dia headers. You need to twist that engine. My car ran 12:20's, average 110 m.p.h. with a 4.88, it was slow reving (real lazy). I changed the gear to a 5:57, and the engine/car came alive. Reved real fast and pulled harder thru all the gear changes. The e.t. dropped down to 11:50's, 60 foot dropped down to 1.51 and m.p.h. picked up to 119. The engine is a 364 c.i. 3 9/16 stroker with 67 2" gm rods that at the time was only 9.1 comp ratio, with a old used GK solid cam, Holley 3310 vac sec, Victor JR intake, ported 292's turbo heads. This was in a 69 Camaro that weighed 3330 lbs. all steel with me in it, 6 pt bar, frame connector's, turbo 400, a GER Super 10' converter and slapper bars. After making more tuning changes and swapped to a 2" race header, the car ran best of 11:00's and 124 m.p.h.
So my gut feelings tell me that their is a 11:70's if not more in you're car with a header/gear change. I was asked by two different guys that raced small blocks at my local strip to help them sort out their car. By making both changes and some more tuning. Both cars picked up on a average of 5 to 7 tenths and 5 to 7 m.p.h.
Ron Miller
Brownstown, Mi
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85Iroc
Junior Member
Posts: 99
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Post by 85Iroc on Oct 11, 2006 12:24:54 GMT -5
Wow. That's a lot of gear Ron. What size tire & how much RPM was it turning thru the traps? I have a 4.88 in mine with a powerglide, had a 10.5:1 355, 26x10 slick & only ran 1/8th mile. It went 6.91 on motor with a converter that was too tight but now I'm thinking I could've used more gear. It would turn 6200+ thru the traps. Then again, I don't think more gear would've worked with nitrous unless I wanted to turn 8000. Sorry to hijack the thread, just interested what tire size & rpm.
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Post by Ron Miller on Oct 12, 2006 8:50:56 GMT -5
Chuck,
My car was N/A and had 10.5 x 28.5 x 15 M/T slicks on it with a 8.5 x 15 Centerline rims. With the 4:88 gear, it would rev real lazy and only turn 6400 to 6800's rpm's in the trap. And that would vary if the car hooked or spun the tires. I tried different shift points (higher of course) on the 1- 2 - 3 to see if a gear change would help. I compared the 60 footers and the 330 ft clock, the car picked up a little. So my thinking was a gear change would help. I was looking at a 5:38 gear for starters. It just so happen that a complete drum to drum 12 bolt was for sale and it all ready had the 5:57 gear in it. On the first dry hop and pass, I could tell by the the way the car reacted and planted my A$$ in the seat that this might be the right gear. The engine rev'd real fast (very responsive), was shifting the 1 - 2 well before the 60 footer, it pulled harder thru all three gears, crossed thru at 7600 rpm's. I played with tire pressures, collector extensions, timimg, went from 10 lbs up to 14 lbs , to get the tires to spin 1 to 1 1/2 turns on the launch, not dead hooking. That helped all over and the car would cross the line at 7700 - 7800 rpm's.
Going up or down on gear sizes will in/de crease you're rpm by 300 - 400 rpm, depending on weight and converter.
Ron Miller
Brownstown, Mi
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Post by shift on Oct 13, 2006 21:46:34 GMT -5
Ron, how big of a cam were you running in your car?
Thanks
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Post by Ron Miller on Oct 14, 2006 9:50:13 GMT -5
I remember it well, I wish I still had that cam. It had a ""Real Mean Nasty Popping Sound"". Heads would turn when I drove up to the staging lines. I even won a $ 20.00 bet with a guy that said it ran/sounded to good to be a solid cam. The cam was a used General Kinetics solid grind. It was called the Red Line Z-Series cam. Advertised duration was 295* intake, 305 * exhaust, @ .050, it was 260*/270* with .535/.555 lift w/a lobe sep angle of 107*. Designed valve lash I think was .026/.028, but it ran better in my engine set at .022/.026.
Competition Products has a Howard's grind very similar to the GK spec's, part # 112541. I picked out a cam for a friend that has a flat top .060 350. Part # 112091, adv dura 290*/298*, @ .050 256*/265* .537/.563 lift w/a lobe sep of 105*. With this cam and piston combo, it has a ton of clearance. I remember about .180 to .225 in/ex. This grind runs and sounds almost like the old GK cam. You can hear the car coming up/down the road before you even see it.
Ron Miller
Brownstown, Mi
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Post by ASD on Nov 5, 2009 1:46:09 GMT -5
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Post by GJEWIOJFQA on Jan 4, 2010 20:22:40 GMT -5
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Post by VKLEJWIOJ on Jan 13, 2010 21:15:46 GMT -5
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Post by LKEWJFIWEOJ on Jan 18, 2010 1:19:05 GMT -5
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I'd keep the heads, just port them, should be good for high 10s at 3200lbs with these.