Engine Tortured By The Hot Rod Bug

Discussion in 'Classic Mustang Specific Tech' started by bacfire, Sep 16, 2012.


  1. bacfire

    bacfire Member

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    ok. I thought I had my winter drivetrain project for my '66 all laid out: new roller 302, ported GT40P heads, RPM intake, and Comp XR262 or equivalent cam, with an AOD & mild stall plus gears in the 3.25-3.5 range. I'm shooting for a 15-20k miles/year daily driver setup with a balance of good power and economy. I have all the parts on hand except the gears, torque converter, headers, and the $300 camshaft.

    Today I ran into a couple of deals too sweet to pass up. I'm picking up a Comp XE268 cam and a set of Windsor Jr heads for a steal. I'm thinking they're a little much for my application, but the 'more power' devil is always right there on my shoulder yapping away. Besides, the heads are ready to run (other than me doing a little clean-up porting) so I won't have to have valve guides and springs for my GT40Ps, and I won't have to buy expensive "P-head" specific headers.

    So I'd like to hear from folks who have run similar combos with overdrive transmissions. The 3.25 gear will put my highway cruise in the 1900-2100 range. Do you think the Jr's and 268 cam will have enough bottom end to pull that efficiently or would I see better fuel efficiency with a little more gear? Or should I resist the the little devil's siren song and go with the original plan?
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  2. bacfire

    bacfire Member

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    Aaaagh! The guy sold my Windsor Jr's before I could get back to him with the money...for $250! I had offered him $300, but he said he had a debt that had to be paid right then. Hmm. Anyhow, I got the cam for $50. I just have to decide whether to use it.
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  3. horse sence

    horse sence Please don't call me Mom SN Certified Technician

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    one thing i have learned as a swap meet scrounger.if you need it, and you see it,and the price is reasonable .buy it then and there. it will probably be gone 15 minutes later.
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  4. rbohm

    rbohm Founding Member

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    use the cam as long as it is in good shape. as for heads, even though you missed the one pair, there will be another coming along soon enough. understand however that you will very likely have to rebuild the heads, so budget for that, figure about $600 depending on how much work you can do yourself.

    as to the gears, with the overdrive trans, i suggest using the 3.55 gears with the cam you selected as they will put the engine in a more efficient rpm range at highway cruise speed.

    as to the trans, check out this site for a full pressure valve body for the AOD so that you dont have to get the TV cable adjustment absolutely perfect.

    http://silverfoxtrans.com/silverfoxtrans.com/VB_AOD.html

    http://www.lentechautomatics.com/rwdmodels.html

    ok that two sites.

    for a torque converter, B&M has a nice street converter called the hole shot. it has a decent stall speed, but it isnt so high as to make the converter unusable on the street.

    tune this combination right and you can expect 25-28mpg on the freeway and about 17-19mpg in town.
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  5. bacfire

    bacfire Member

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    The heads were in great shape and didn't seem to need anything more than a little cleanup porting and valve lapping. $0.00 there. But, no use crying over 'em now. I have a set of nicely ported GT40Ps I'll use if nothing else comes along in the next couple months. My goal is to have the drivetrain finished and swapped out in time for the Hot Rod Power Tour next June, so I have some time.

    I'm glad you mentioned the B&M converter. I had been looking at that one, but the general online consensus seems to be that B&Ms are very inefficient and poorly made. I'm not really worried about breaking it...the car will never see a track and won't have enough traction to really stress the drivetrain...but the prospect of losing fuel economy to a inefficient converter worries me. My experience with a mild street automatic combo is very limited. I never really worried about anything below 4000 rpm in the few auto cars I've worked with in the past :D I do know I won't be spending $800+ on a torque converter for this car, so I'm sure I'll be raising this issue again before too long.
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