When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Probably not. What does the mounting flange look like? To run a Q-Jet with Vortec heads, you'll need a spread bore intake made for Vortec heads. Like an Edelbrock Performer 2116:
i think I'd rather just rebuild the heads and do the complete upgrade later this year instead of investing a bunch on parts that will only be used for a few months. Overall not a bad idea and if all else falls might be a good backup to TPI.
i think I'd rather just rebuild the heads and do the complete upgrade later this year instead of investing a bunch on parts that will only be used for a few months. Overall not a bad idea and if all else falls might be a good backup to TPI.
Please post some more photos! You'll get much better advice (or, at least, more of it), if we can see what you can see.
Will a q-jet fit on a TBI intake? If so then I have a vortec intake i can use.
there is no TBI intake for vortec heads. there are TBI heads that have the middle 2 bolts on each side of the intake pointing straight down. they get mistakenly called vortec heads. they are just smog heads with 72 cc chambers and a funny bolt pattern. true vortecs only have 4 manifold bolts each side.
nothing fits on a TBI intake but a TBI and tbi intake only fits 87 to 95 tbi heads.
Last edited by derekderek; Feb 8, 2023 at 08:26 AM.
this is the vortec manifold bolt pattern.
there is no TBI intake for vortec heads. there are TBI heads that have the middle 2 bolts on each side of the intake pointing straight down. they get mistakenly called vortec heads. they are just smog heads with 72 cc chambers and a funny bolt pattern. true vortecs only have 4 manifold bolts each side.
nothing fits on a TBI intake but a TBI and tbi intake only fits 87 to 95 tbi heads.
This is the head i bought from Scoggin-Dickey.
Intake from Summit or maybe Scoggin-Dickey cant remember exactly where. But yes def not gonna work on q-jet without adapter. SDPC makes an intske for TPI for these heads. And from what i recall these heads are the vortec design. I have the paperwork stored away. And the TBI. Had all yhis running on a C10 years ago, would turn tires at lights if I touched the accelerator to hard.
Hi,
There is a code by the spring and the cover on the bottom of the differential, codes are below. But since you have to jack it up to crawl under there, get both wheels off the ground, put a mark on the drive shaft and on one tire, spin the tire one turn and count the revolutions of the drive shaft...3.5 revolutions would be 3.55-(hard to be exact)....
Oil leaking from the bellhousing could be the two-piece RMS leaking. Burning oil could be a variety of things - scoured/scratched cylinders, improper size/improperly installed piston rings/skirts, worn cylinders with forged pistons, etc etc. Lots of blue smoke until warmed up would possible point to running forged pistons (which will expand when warmed up), combined with some type of issue. Is there any clatter when cold? A compression test probably wouldn't hurt here, or better - a leakdown, which is far more comprehensive. In my experience, I start with those before I go tearing an engine apart.
And buying a vette to use a kick butt motor you have laying around is a great idea, IMO. That way, you can store the motor in there now and troubleshoot it another day while running your spare motor, whether EFI or carbed. I have one myself that I have been building that I would love to find a donor C3 (68-72 or 80-81) to put it in.
Last edited by Corvette-ZL1; Feb 8, 2023 at 09:29 AM.
Oil leaking from the bellhousing could be the two-piece RMS leaking. Burning oil could be a variety of things - scoured/scratched cylinders, improper size/improperly installed piston rings/skirts, worn cylinders with forged pistons, etc etc. Lots of blue smoke until warmed up would possible point to running forged pistons (which will expand when warmed up), combined with some type of issue. Is there any clatter when cold? A compression test probably wouldn't hurt here, or better - a leakdown, which is far more comprehensive. In my experience, I start with those before I go tearing an engine apart.
And buying a vette to use a kick butt motor you have laying around is a great idea, IMO. That way, you can store the motor in there now and troubleshoot it another day while running your spare motor, whether EFI or carbed. I have one myself that I have been building that I would love to find a donor C3 (68-72 or 80-81) to put it in.
That engine in the pictures above has Keith Black Forged pistons and never smoked. But I paid good money for the short block assembly so it was probably done right. Something tells me that the engine was not rebuilt as claimed, maybe not fully. I will run tests Friday, I'll pick up a leak down tester, buy or rent if I can.
i stand corrected. i have never heard of a TBI intake for vortec heads. i guess tbi people want to upgrade to vortec heads too. but, nothing fits that intake but a TBI unit. whereas there are adapters to put TBI onto spread bore 4 barrel intakes. GM used them for years. TBI is a nice emissions-economy efi setup. with the 454 unit you can make some power, but it is still about 500 cfm tops. and it ain't sexy. nothing uglier but a rochester 2 barrel carb. to run TBI in a 75 vette is near the amount of converting needed for more performance-oriented efi setups. wiring in the ecu and all sensors, etc. the advantage is only need 13 psi instead of 40 to 60. but the lower fuel pressure means it doesn't atomize as well also. i don't see the value in running this setup in a corvette. the Jegs version of the spread bore carb vortec intake. https://www.jegs.com/i/JEGS/555/5130...RoCzNEQAvD_BwE unfortunately you need a gasket that is half the price of the new manifold. vortec trucks are in junk yards all over because the intake gasket failed and watered the engine. use this gasket for a vortec head. https://shop.advanceautoparts.com/p/...E&gclsrc=aw.ds
i stand corrected. i have never heard of a TBI intake for vortec heads. i guess tbi people want to upgrade to vortec heads too. but, nothing fits that intake but a TBI unit. whereas there are adapters to put TBI onto spread bore 4 barrel intakes. GM used them for years. TBI is a nice emissions-economy efi setup. with the 454 unit you can make some power, but it is still about 500 cfm tops. and it ain't sexy. nothing uglier but a rochester 2 barrel carb. to run TBI in a 75 vette is near the amount of converting needed for more performance-oriented efi setups. wiring in the ecu and all sensors, etc. the advantage is only need 13 psi instead of 40 to 60. but the lower fuel pressure means it doesn't atomize as well also. i don't see the value in running this setup in a corvette. the Jegs version of the spread bore carb vortec intake. https://www.jegs.com/i/JEGS/555/5130...RoCzNEQAvD_BwE unfortunately you need a gasket that is half the price of the new manifold. vortec trucks are in junk yards all over because the intake gasket failed and watered the engine. use this gasket for a vortec head. https://shop.advanceautoparts.com/p/...E&gclsrc=aw.ds
You are correct. Have no plans to use the TBI on my vet. SDPC has a TPI intake for the vortec heads. I've got a complete TPI setup and ECU already. Howell EFI can make harness, dynamicEFI for the ECU upgrade and a few weeks of wrench should do it. Of course new sending unit and fuel pump, MAF coil setup and other sensors need to be added.
I used dynamicEFI on the TBI and it was nice. Not the best but i know how it works.
my 1st goal is to attempt to get this engine running. Drive the car on weekends in summer while I'm accumulating all the parts and prototype assembly on a stand then transplant.
i looked at and test drove a '75 last fall, it was not that clean looking on the inside, that's a pretty clean car ! someone took care of it!
curious what the ballpark of what they are asking for this?
i have no advice on the engine, good luck!
Originally Posted by HackTheBox;160
6237006
Side view on transport.
Interior Clean, seats need some work but overall clean and everything is working.
best bet, drive the smoker-choker for a month. get a feel for what else the little b!tch is gonna demand you buy her. she won't care that you spent 2k on a an efi setup and the engine. "I want front end bushings! I want new belts and hoses! I want new brake lines!" and first time it rains? "I want new T-top seals!"
Please post some more photos! You'll get much better advice (or, at least, more of it), if we can see what you can see.
Topped off the oil, and started up cold. Smoke is from driver side only and a distinct blow by sound. Will do leak down tester this weekend with my kids.
I took the corvette out for a drive today just to see how she runs. There's definitely some roughness to the engine. Doesn't run like I'm use to. However she not bad but definitely lacking that get up and go that a tuned engine should have.
I ran a practice run on my engine for leak down and for a cold block that hasn't run in several years all cylinders run about 4% loss. Worst was 7%. But I may have not been 100% TDC it was tough to hold the crank perfect and the cam I have in there is pretty aggressive.
1st thing tomorrow I'll pop the covers off the vet and snap some pictures of the rockers and lifters. Run the leak down and post the results.
I'll get pictures of plugs to should show any combustion issues or fouling due to burning oil.
Pulled plugs today, just about every plug was fouled. 5 was actually in good shape. 2 by far the worst. It probably was a dead miss due to over use of zip ties on plug wires. When we remove the zip tie, the plug wire was burn thru and shorting to engine bracket. It practically fell apart.
Could this direct short kill the coil?
Cylinder 1 had good leak about 5% loss. Ran out of day light. Will do rest tomorrow.
Several drips while idling doesn't sound like a typical rear main seal leaking, I would look at the oil pressure line fitting at the back of the engine, valve covers etc. for starters. Should be easy enough to locate the source of the leak if it's leaking that much oil.
...there is a pressure switch at the back of the block on '74 & up as they went to an electric gauge by then unless someone installed an aftermarket mechanical oil pressure gauge. 1973 was the last year to have the oil pressure line to the mechanical oil pressure gauge in the instrument cluster.
...there is a pressure switch at the back of the block on '74 & up as they went to an electric gauge by then unless someone installed an aftermarket mechanical oil pressure gauge. 1973 was the last year to have the oil pressure line to the mechanical oil pressure gauge in the instrument cluster.
I'll check that too. Thank you
Also the valve cover bolts were super loose. Looks like oil was leaking out on sides, but still doesn't explain coming off the back from the bellhousing. So either rear main seal or pressure guage.
paul. who was the girl in your previous avatar? (better looking than this one. bit of a dog...) hack. valve covers can show leaks from the back. distributor gasket. oil pressure switch. intake manifold china wall. if rear main seal, the front of flywheel will be oily.
Also the valve cover bolts were super loose. Looks like oil was leaking out on sides, but still doesn't explain coming off the back from the bellhousing. So either rear main seal or pressure guage.
Here why zip ties are not used on soft silicon or any plug wires. Vibration and chafing caused insulation to break down then burn the wires arcing to ground.
Pulled plugs today, just about every plug was fouled. 5 was actually in good shape. 2 by far the worst. It probably was a dead miss due to over use of zip ties on plug wires.
Those spark plug gaps look enormous! Granted, I'm used to .032" for points and not HEI but still...
