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.
What were you using your cars for when you installed your kit? Were these drag cars or just weekend warrior type vehicles?
Why did you feel the need to install them?
One was a 505 BBC with a TH400 in a Camaro-- the guy loved the way it drove on the street- and the drag strip told him to go home after 1 pass and not come back without a full cage.
Another was a 65 GTO- 455 Pontiac and a TH350- no street for that one, he raced on slicks every weekend.
I did a 700-R4 for a Camaro the guy ran Autocross and road course stuff.
Did a 200-4R in a Monte Carlo-- that one was a blast- set it up with the Buick GN servos.. It would bark tires in 3 gears with a pretty tame 350.
Personally, I like the firm shift without any feeling of slipping.
I know I'm going to get some flack for this, but not I didn't. I installed the crank gear advanced based on the cam card specifying 108 ICL if installed straight up.
How common is it to have a cam with incorrect cam specs? Different ICL than specified for example?
How much are they usually off?
It wouldn't be uncommon to find the cam off one way or the other slightly ,or dead-on, but the timing set is more suspect. You can get a stack effect also - with the cam off one degree and the timing set off 3 degrees for a total of 4* retarded/or over advanced, or worse.
If something seems just not right after being run but this wasn't checked then you then have to go back to do it or wonder if that could be the problem or something else !
With that cloyes hi$ Tcover ... seems you can adjust the CAM GEAR timing with bushings ... thru an access hole in Tcover ... without having to pull damper etc,... right?
With that cloyes hi$ Tcover ... seems you can adjust the CAM GEAR timing with bushings ... thru an access hole in Tcover ... without having to pull damper etc,... right?
You probably could if bought a set with those adjustments. Mine is this one:
I can only install the crank gear retarded, straight up, or advanced. With this mild build I didn't see the need to get one with the cam gear adjustments.
It wouldn't be uncommon to find the cam off one way or the other slightly ,or dead-on, but the timing set is more suspect. You can get a stack effect also - with the cam off one degree and the timing set off 3 degrees for a total of 4* retarded/or over advanced, or worse.
If something seems just not right after being run but this wasn't checked then you then have to go back to do it or wonder if that could be the problem or something else !
I had no idea these sets could be that far off. Again, this is my first engine rebuild project, but the videos I've seen show the difference being fractions of 1 degree.
I'll make sure to do this before I go any farther.
The cc's of the heads is pretty important to do now if you want to know later. Made a difference in my build. Yours is not close to the edge but if you have any issue after the build, you will always wonder if this was a factor. Easy fast check.
Cam timing is usually pretty close to spec, unless you change it. You can check or alter cam timing even after the build with some dissasembly.
I have degreed over 200 camshafts in my life and can tell you that only 3 were off (only one was a shelf cam, the other two were custom ground).
But if I built 200 engines and degreed 199 camshafts.....it would be THAT ONE I didn't check that would be off.
"You think you know....but you don't really know..." Dick Maskins-Owner, Dart Machine-2004
The cc's of the heads is pretty important to do now if you want to know later. Made a difference in my build. Yours is not close to the edge but if you have any issue after the build, you will always wonder if this was a factor. Easy fast check.
Hey Stinger, can you tell me when you measured, how much difference was there between the bowls on the same head?
I could see there being a difference between 2 different heads, and I guess you could shave 1 of the heads slightly more than the other to correct. But did you see much difference between the bowls for #2 and #8 cylinders, for example?
Hey Stinger, can you tell me when you measured, how much difference was there between the bowls on the same head?
I could see there being a difference between 2 different heads, and I guess you could shave 1 of the heads slightly more than the other to correct. But did you see much difference between the bowls for #2 and #8 cylinders, for example?
Plus or minus .5cc We usually assume double hump fuelie heads have 64cc chambers but the large valve versions have had the chamber wall cut at the factory for improved flow around the perimeter of the intake valve which raises the head volume a few cc's. If the valves are sunk deeper from a valve job (or 2) the chambers will measure out bigger as well. We went from "assumed 64cc's" to an actual measured 68cc's. That is a pretty huge difference. Takes just a few minutes to know for sure.
One more "gnat's-***" cc / SCR / Quench consideration.
was reading thru an online (? scribd) ca 1976 Bill grumpy Jenkins how-to build a chevy race motor where he detailed different embossed shim gaskets
He writes embossed shim gaskets compress to about 0.003" MORE than shim material thickness ... e.g. 0.015" shim compresses to 0.018"
Jenkins charted this out with photos & part numbers. He also suggests you can stack shims but that 0.003" TOTAL remains constant; even for the stack.
I'd thought of this before but only fleetingly and haven't used it when estimating volume / SCR / Quench; the late Jenkins studied and published it. Henceforth, I'll use it.
One more "gnat's-***" cc / SCR / Quench consideration.
was reading thru an online (? scribd) ca 1976 Bill grumpy Jenkins how-to build a chevy race motor where he detailed different embossed shim gaskets
He writes embossed shim gaskets compress to about 0.003" MORE than shim material thickness ... e.g. 0.015" shim compresses to 0.018"
Jenkins charted this out with photos & part numbers. He also suggests you can stack shims but that 0.003" TOTAL remains constant; even for the stack.
Not sure what is defined as embossed, but i bought the 1094 felpro gasket. Are all gaskets embossed?
Does that mean you need to add 0.003 to all gasket thicknesses for calculation?
Since the 1094 is a metal shim and the block wasn't decked, i am planning to spray some copper cote on it which will also add a few thousanths of thickness as well. I hope this doesn't screw up the quench too much.
Not sure what is defined as embossed, but i bought the 1094 felpro gasket. Are all gaskets embossed?
Does that mean you need to add 0.003 to all gasket thicknesses for calculation?
Since the 1094 is a metal shim and the block wasn't decked, i am planning to spray some copper cote on it which will also add a few thousanths of thickness as well. I hope this doesn't screw up the quench too much.
Does your gasket appear perfectly flat or does it seem to have raised areas that are stamped? ... raised not sprayed ... raised not coated ... Slightly raised via deforming the metal shim?
-edit- slightly raised ... as a dent or a ridge around water holes, around bore holes ... from deforming the metal shim
Jenkins' book is more than 40 years old. Look about page 90. Seems he says add 0.003" ... you read, you interpret. Someone here's bound to argue regardless yes or no. Book's old ... he references brand Detroit Gasket ... long ago absorbed by Freudenberg NOK ... then Corteco etc.
0.003" probably about +/- 0.6cc ... if your street target is about 0.040" ... that ain't gonna screw the pooch. ... Gnat's ***
so i made some progress on rebuilding my 350 motor (355 now).
After a lot of BS with these vortec heads, they are assembled and on the engine. I'm a little bit worried though...
Since i didnt have my engine block decked because i wanted to keep the matching numbers, i decided to spray copper coat on the felpro 1094 0.015" gasket i purchased. I didnt realize how sticky that stuff is and how it can attract dust and particles.
I tried to clean the mating surfaces as best i could with acetone, but as i placed the head on top of the gasket, i noticed a few tiny particles came out of the water jacket in the head and landed on the gasket.
I should have blown the head out a bit better obviously.
So i took the head off again, used acetone to wipe the gasket off where the particles landed, and resprayed the gasket with copper coat. After i removed the head, i saw there were areas on the gasket that contacted the head and the copper coat came off. I resprayed it, but i'm wondering if there will be some thicker spots with copper and thinner spots.
What are people's opinions of this stuff?
I'm kind of leaning toward removing the heads again and just getting another pair of 1094 gaskets and installing them without the spray. With the gasket being so thin, I'm worried these little particles or thickness of the copper coat will cause an issue.
Any thoughts?
Last edited by mongoose87; 04-09-2019 at 06:57 PM.
...1 more thing i'm hoping to get the forum's advice on:
I am measuring the pushrod length right now, and getting ready to order them, but not really sure what kind to get with my roller cam conversion.
The valve springs i have should put around 350 lbs open pressure, so I'm not sure if this warrants hardened pushrods, or something thicker.
I am running self-aligning rockers, so I do NOT need hardened for guideplates.
When would someone look at 3/8 pushrods instead of the standard 5/16?
Would 5/16 hardened still be preferred over 3/8 regular?
Should regular 5/16 be fine for 350 lbs open pressure?
so i made some progress on rebuilding my 350 motor (355 now).
After a lot of BS with these vortec heads, they are assembled and on the engine. I'm a little bit worried though...
Since i didnt have my engine block decked because i wanted to keep the matching numbers, i decided to spray copper coat on the felpro 1094 0.015" gasket i purchased. I didnt realize how sticky that stuff is and how it can attract dust and particles.
I tried to clean the mating surfaces as best i could with acetone, but as i placed the head on top of the gasket, i noticed a few tiny particles came out of the water jacket and landed on the gasket.
I should have blown the head out a bit better obviously.
So i took the head off again, used acetone to wipe the gasket off where the particles landed, and resprayed the gasket with copper coat. After i removed the head, i saw there were areas on the gasket that contacted the head and the copper coat came off. I resprayed it, but i'm wondering if there will be some thicker spots with copper and thinner spots.
What are people's opinions of this stuff?
I'm kind of leaning toward removing the heads again and just getting another pair of 1094 gaskets and installing them without the spray. With the gasket being so thin, I'm worried these little particles or thickness of the copper coat will cause an issue.
Any thoughts?
pretty sure felpro says Not to apply more coating to 1094 because it already has a coating.
On the other hand ... essentially same shim ... felpro 7733SH1 has no coating ... fire at will ... costs about 1/3$ of 1094
FYI ... both 1094 & 7733SH1 are embossed steel shim
On the 1094 instructions it says to apply sealant if the required surface roughness is not ideal.
I was mainly trying to play it safe with this old block
03-05-2019, 09:15 PM
