Search found 29 matches

by edherba
Fri Oct 16, 2020 8:03 pm
Forum: Ask your Mechanical Questions here
Topic: 1963 Corvair Engine detonation
Replies: 52
Views: 3060

Re: 1963 Corvair Engine detonation

No oil consumption issues that I noticed. Puddling in cyl 5 is because car is parked on a floor with a slope towards the floor drain and that cyl is the lowest point. I'll keep an eye on that though.
by edherba
Fri Oct 16, 2020 6:33 pm
Forum: Ask your Mechanical Questions here
Topic: 1963 Corvair Engine detonation
Replies: 52
Views: 3060

Re: 1963 Corvair Engine detonation

I bought some octane booster and put the whole bottle in a full tank of gas. The detonation was greatly reduced and would only be heard slightly when accelerating hard from stop. Oil temp is still a concern at around 255F after 15 minutes of driving in town. I may try swapping the carb jets from #51...
by edherba
Sun Oct 11, 2020 7:22 am
Forum: Ask your Mechanical Questions here
Topic: 1963 Corvair Engine detonation
Replies: 52
Views: 3060

Re: 1963 Corvair Engine detonation

From Clarks Corvair page 7: "Solid copper head gaskets, reuseable for standard bore thru 3½” (a must on +.030 or larger bores to avoid gasket “hang-over”). Can also be used to adjust for cylinder head resurfacing and lowering compression for running on regular gas. Stock thickness is approximately ....
by edherba
Sun Oct 11, 2020 7:07 am
Forum: Ask your Mechanical Questions here
Topic: 1963 Corvair Engine detonation
Replies: 52
Views: 3060

Re: 1963 Corvair Engine detonation

Yes, 255F is oil temp.
I did not machine the head where the gasket seats. But over the past 50 years, maybe someone else did. How do I know? Can I measure the head gasket seat depth? What should it be?
by edherba
Sat Oct 10, 2020 7:26 pm
Forum: Ask your Mechanical Questions here
Topic: 1963 Corvair Engine detonation
Replies: 52
Views: 3060

Re: 1963 Corvair Engine detonation

So I too a break from the Corvair for 6 weeks or so. I redid the compression test (engine was sitting for 6 weeks). The values are as follow: cyl 1 -180psi cyl 2- 160psi cyl 3- 170psi cyl 4- 180psi cyl 5- 195psi (I noticed oil puddling in the cylinder since car was sitting tilted towards cyl 5) cyl ...
by edherba
Mon Sep 07, 2020 5:52 pm
Forum: Ask your Mechanical Questions here
Topic: 1963 Corvair Engine detonation
Replies: 52
Views: 3060

Re: 1963 Corvair Engine detonation

The carbs are using a #51 jet. How do you know if the car is running too lean? The idle mixture screw is turned out 3 turns so it is running rich on idle.
Should I buy a #52 or #53 and try it? Trying to figure out how to reduce engine temp. It doesn't detonated until it gets around 215F.
by edherba
Sun Aug 23, 2020 11:18 am
Forum: Ask your Mechanical Questions here
Topic: 1963 Corvair Engine detonation
Replies: 52
Views: 3060

Re: 1963 Corvair Engine detonation

I question the engine compression value of 180psi because, I cranked it over about 7-8 times and the gauge just gets pumped up. How may times should l I turn it over before I take the gauge reading? I can order a #52 jet and try that on both carbs. Cam has same lift as original but slightly longer d...
by edherba
Sat Aug 22, 2020 7:21 pm
Forum: Ask your Mechanical Questions here
Topic: 1963 Corvair Engine detonation
Replies: 52
Views: 3060

Re: 1963 Corvair Engine detonation

yes, it has done it since it was rebuilt. I bought a carb rebuild kit from Clarks and told them I had a 63 with powerglide and the 102 HP engine. I don't know for sure which in one they gave me. I assume #49 as in chart on page 59 of Clarks catalogue. I have the mixture screws unscrewed about 3 1/2 ...
by edherba
Sat Aug 22, 2020 2:57 pm
Forum: Ask your Mechanical Questions here
Topic: 1963 Corvair Engine detonation
Replies: 52
Views: 3060

Re: 1963 Corvair Engine detonation

I rebuilt the engine 2 years ago, so I know the engine is free of any debris. I have the oil temp sensor in the hollow bolt holding the oil filter. I never checked the internal flow of the oil cooler. Are there tiny passages that could be blocked? I notice the detonation only at higher temps. Why is...
by edherba
Sat Aug 22, 2020 1:04 pm
Forum: Ask your Mechanical Questions here
Topic: 1963 Corvair Engine detonation
Replies: 52
Views: 3060

Re: 1963 Corvair Engine detonation

I am using 94 octane. Spark plugs NGK BR5HS. Yes, the idle returns to normal when stopped.
by edherba
Sat Aug 22, 2020 11:32 am
Forum: Ask your Mechanical Questions here
Topic: 1963 Corvair Engine detonation
Replies: 52
Views: 3060

Re: 1963 Corvair Engine detonation

also forgot to mention:
The damper doors open fully. No leaves or dirt around cylinder cooling fins either.
Engine temp is from oil temp gauge I added.
Engine does not detonate when it is cooler, say around 180F.
by edherba
Sat Aug 22, 2020 11:28 am
Forum: Ask your Mechanical Questions here
Topic: 1963 Corvair Engine detonation
Replies: 52
Views: 3060

Re: 1963 Corvair Engine detonation

Hi again, I followed pages 8-9 of the "Tuning the Corvair Engine" where I reset the idle setting. Then again at 1200 RPM using the vacuum gauge (pages 11-13), I checked it and the vacuum is 10 inHg with no change when I pinch the left and right side. That's progress. I then connected the vacuum gaug...
by edherba
Sat Aug 15, 2020 5:47 pm
Forum: Ask your Mechanical Questions here
Topic: 1963 Corvair Engine detonation
Replies: 52
Views: 3060

Re: 1963 Corvair Engine detonation

Thanks for all the information. I will start the process again. During the tuning, the fan belt snapped. Had to push the car a mile back home because I thought it was a smart idea to work in a parking lot away from the neighbors. Luckily some sympathetic neighbors an my wife helped push it back home...
by edherba
Sat Aug 15, 2020 1:04 pm
Forum: Ask your Mechanical Questions here
Topic: 1963 Corvair Engine detonation
Replies: 52
Views: 3060

Re: 1963 Corvair Engine detonation

another things I just realized. Bbodie52 mentioned "The vertical port only applies vacuum to the vacuum advance mechanism as the throttle is opened" I am connecting my vacuum gauge to the vertical spark port which goes to the distributor vacuum advance. Therefore, I would not get vacuum on the RHS i...
by edherba
Sat Aug 15, 2020 12:50 pm
Forum: Ask your Mechanical Questions here
Topic: 1963 Corvair Engine detonation
Replies: 52
Views: 3060

Re: 1963 Corvair Engine detonation

Hi Guys. So I was working on trying to resolve the very low vacuum on the RHS carburator. I changes the base gaskets and plastic spacer with new ones. The old plastic spacer had some small cracks but not all the way through. I also changed the short rubber hose from the crossover tube to the carb ba...
by edherba
Thu Aug 06, 2020 12:03 pm
Forum: Ask your Mechanical Questions here
Topic: 1963 Corvair Engine detonation
Replies: 52
Views: 3060

Re: 1963 Corvair Engine detonation

is it a good or bad idea to put a bit of gasket sealer on each side of the carb gaskets?

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