General engine tech -- Drag Racing to Circle Track
Thanks for sharing. Cool
How many engine mods to run 12.60 then? Or was that original motor setup?
Well I started in stages over a period of 3-4 years. When new I did basic things like rejetting the factory 585 Holley and with the dealer installed 3.73 gear in the little 7.5 rear I was running 14.70's with the stock Gatorbacks spinning like crazy.
Next I put a better curve in the distributor, added the Kaufmann hot hyd. roller cam in place of the factory roller. Cam had 212/222 duration with .496 lift something like the old 428 CJ cam. Also swapped on a pair of 1969 351W heads C90E that somebody gave me 10 yrs. before I owned a Ford.
I cleaned those up and added 1.900 intake valves and ground out the exhaust smog hump in the port. Topped it with a Eddy 289 Performer doctored up to look like the smaller factory aluminum intake. On the stock tires again would run easy 14.30's at 102 MPH spinning those greasy Gators with an easy 1500 RPM launch. Installed a pair of 7.5 inch x 26 Hoosier oval track recaps and ran a 14.0 at 103 with easy launches due to that 7.5 rear end.
In 1989 I built my own Tri-Y headers with a single collector exit much like the old Camaro SLP headers back then from a Dougs Header kit since I was still running the factory single convertor mid pipe. Also had a cutout added in front of convertor. With a fresh pair of the M&H G-60-15 street slicks
I ran 13.30's at 104 again not beating on it with the 7.5 rear.
Next year I improved the air filter assembly with a NASCAR type cowl setup and moved up to the Ford B 303 cam and got in the 12.90's at 108 with easy launch 2.04 60 foot times...still 7.5 rear end and 3.73 gear and the little 585 factory Holley carb.
In the early 90's I swapped on the new iron GT-40 heads and the Weiand Excellerator small single plane intake along with a new 9 inch Ford rear setup with 4.11 gear and Detroit Locker. By this time I had replaced the stock T-5 trans with the beefier latest upgraded Ford T-5 trans.
With those M&H G-60-15 tires and some T-bird aluminum spare front runners I was in the 12.60's at a bit over 109. I never really beat on the thing with hard launches. More like 3000-3500 launch.
I tried a Holley 750 DP but it was only worth about a .2 MPH so put that factory "tweaked" 585 Holley back on.
Those were some fun times in the early 5.0 Mustang days!
Very cool. Those little motors seem to respond well.
427 do the 69 heads flow that much better than 85. With the right combo knowing what you know do you think you can get enough hp out of stock heads and intake to go mid 12 or quicker? Sounds like the 7.5 rear is the weak link.I think it is but you have done extensive work I’d be interested in hearing.The reason i ask we are having a discussion on 302 on another thread on this subject. Not many have done step by step such as you did.
I have some info someplace that had listed the flow numbers of various SBF heads but from what I remember the C90E head did flow a bit better than the stock 85 head plus it bumped up the compression a bit with the smaller chamber. Nowdays many better heads to choose from.Steve.k wrote: ↑Tue Jun 30, 2020 12:23 pm427 do the 69 heads flow that much better than 85. With the right combo knowing what you know do you think you can get enough hp out of stock heads and intake to go mid 12 or quicker? Sounds like the 7.5 rear is the weak link.I think it is but you have done extensive work I’d be interested in hearing.The reason i ask we are having a discussion on 302 on another thread on this subject. Not many have done step by step such as you did.
Very true. Even the cheap e street edelbrock has decent flow. Thanks 427.I thought the 69 had flow around 220cfm.