thearborbarber
1/2 ton status
I just put summit aluminum heads on my 91 sub with a tbi. Who would be a good source to have tweak my factory tune and burn a new chip burned?
CK5
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TBI Tuner
- Thread starter thearborbarber
- Start date
I have Howell engineering do 2 different ones for me now. They are the original engineering company that designed the system. Ask for Troy, if possible give him airflow numbers for those heads, compression, cam timing.
He'll also want the last 4 of the computer part number #
thearborbarber
1/2 ton status
Thanks!!
thearborbarber
1/2 ton status
I got my prom from Troy today. I gave him some rudimentary scan data and wide band info and he hit it out of the park. PE is spot on, BLM and integer is really close and way more power across the board. Thanks again for the tip.
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You change anything else on the engine besides the heads? Worth the increase in power?
Any chance you've got your datalogs to share from after the AL head swap, but before/after the new PROM?
thearborbarber
1/2 ton status
Depends on if $1500 is worth 30hp? In hind sight I'd do a cam with the heads. I use an auto xray ezlink to scan with. Unfortunately I don't have a windows machine old enough to download the data with. I just watch the numbers as I make a run.
What heads did you end up running? I thought the summit heads were around ~$900 a pair? Or is that with the xray and chip burn?
Did anything stick out with you on numbers as you were watching the data before PROM burn? Quite lean, not much diff, etc?
I had been looking at heads like these before I just settled on a crate engine https://www.summitracing.com/parts/sum-162108/overview/make/chevrolet But the roller cam, Vortec intake pattern, and my self-aligning roller rockers caused additional complications that kept bumping up the price. The Edelbrocks at $1500 were the only "bolt ons" that would have worked for me as-is...and that is $400 less than a complete GM crate Vortec engine.
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X2 on the more details on the heads request, please.
thearborbarber
1/2 ton status
There are the heads I used,
https://www.summitracing.com/parts/SUM-162108
My review is the one with the pictures.
$200 for the prom, Both exhaust manifolds were toast. I stripped the the center out of my power steering pump shaft putting the pulley back on so a new pump. Gasket kit, new head bolts. Oh ya my distributor was shot and new plugs and wires.
Pre-prom lean cruise numbers weren't terrible, Block learn and integer were adding fuel but nothing maxed out (high 130s). Open loop idle and power enrichment were quite rich at 11.5. It also didn't want to rev, it almost felt like the swirl port heads were still in there.
Post prom really woke the engine up. Using my g-tech, I picked up 0.8 of a second in the quarter mile going from 19.99 seconds to 19.19 seconds. Trap speed went from 68 to 70mph. PE is not 12.5 to 12.8 and lean cruise hovers around 128ish on blm and integer.
https://www.summitracing.com/parts/SUM-162108
My review is the one with the pictures.
$200 for the prom, Both exhaust manifolds were toast. I stripped the the center out of my power steering pump shaft putting the pulley back on so a new pump. Gasket kit, new head bolts. Oh ya my distributor was shot and new plugs and wires.
Pre-prom lean cruise numbers weren't terrible, Block learn and integer were adding fuel but nothing maxed out (high 130s). Open loop idle and power enrichment were quite rich at 11.5. It also didn't want to rev, it almost felt like the swirl port heads were still in there.
Post prom really woke the engine up. Using my g-tech, I picked up 0.8 of a second in the quarter mile going from 19.99 seconds to 19.19 seconds. Trap speed went from 68 to 70mph. PE is not 12.5 to 12.8 and lean cruise hovers around 128ish on blm and integer.
I haven't paid attention, are the TBI heads 72CC or were they 64CC?
When I was looking at the AL heads I was hoping to get some 58CC chambers to get compression up around 10:1 since the cast iron Vortecs will handle 9.4:1 without issue on 87 octane, but if you went from 72CC to 62CC chambers, that is a fairly significant increase. Has the block been decked or anything to affect compression height? What head gasket did you use?
When I was looking at the AL heads I was hoping to get some 58CC chambers to get compression up around 10:1 since the cast iron Vortecs will handle 9.4:1 without issue on 87 octane, but if you went from 72CC to 62CC chambers, that is a fairly significant increase. Has the block been decked or anything to affect compression height? What head gasket did you use?
thearborbarber
1/2 ton status
Depends on the head. 191 heads have 76cc chambers and 193 heads have 64cc. I had 193s on my 91
I didn't deck my block and I don't know how thick the head gasket was (possibly 0.039" digging around summits catalog). I used a felpro kit from orielly's
http://www.oreillyauto.com/site/c/d...sket+set_5013172_2079&keyword=head+gasket+set
I didn't deck my block and I don't know how thick the head gasket was (possibly 0.039" digging around summits catalog). I used a felpro kit from orielly's
http://www.oreillyauto.com/site/c/d...sket+set_5013172_2079&keyword=head+gasket+set
