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Search found 352 matches

by Tom68
Wed Sep 28, 2022 4:53 pm
Forum: Engine Tech
Topic: SBC & oil pressure at idle
Replies: 16
Views: 476

Re: SBC & oil pressure at idle

Yes, this is a stock GM spring. When I spun the pump, I got a good amount of oil on the rockers (all of them). so I was convinced all was good. Didn't check for pressure as I don't have an oil pressure gauge to do it with and I normally fire the engine up in the car and look at the car's oil pressu...
by Tom68
Wed Sep 28, 2022 2:03 am
Forum: Engine Tech
Topic: 034 Chevy Bowtie Semi Finished Heads
Replies: 10
Views: 354

Re: 034 Chevy Bowtie Semi Finished Heads

Do you reckon you'd ever find a set ?

Lot of work to get those unfinished low port heads useable.

Vortecs don't crack without reason do they ? something must be causing the cracking.
by Tom68
Wed Sep 28, 2022 1:41 am
Forum: Engine Tech
Topic: SBC & oil pressure at idle
Replies: 16
Views: 476

Re: SBC & oil pressure at idle

Belgian1979 wrote: Wed Sep 28, 2022 1:26 am Ok, going to get it back, take the pan off and take a look.
If your doing that you need to do this..https://youtu.be/p3qsQU6grvc..but I'll bet you find you get 38 psi doing it if you have a standard GM spring.
by Tom68
Tue Sep 27, 2022 11:31 pm
Forum: Engine Tech
Topic: Flathead Flow Bench Testing - What is Your Method?
Replies: 13
Views: 463

Re: Flathead Flow Bench Testing - What is Your Method?

Smoke test and a glass head.
by Tom68
Tue Sep 27, 2022 6:46 pm
Forum: Engine Tech
Topic: SBC & oil pressure at idle
Replies: 16
Views: 476

Re: SBC & oil pressure at idle

38 psi sounds about right for a standard spring, you may still only have 38 at revs too if the bypass is big enough.

Be careful swapping springs between different pumps, you then need to compare the installed length.
by Tom68
Tue Sep 27, 2022 3:37 am
Forum: Engine Tech
Topic: Flathead Flow Bench Testing - What is Your Method?
Replies: 13
Views: 463

Re: Flathead Flow Bench Testing - What is Your Method?

You'd have to pull from the sump I'd imagine, didn't Smokey used to flow some engines that way ?


Dunno about the flow but here's a picture from an alternative universe.
.
309208303_10221744030366920_5011384209509226153_n.jpg
by Tom68
Tue Sep 27, 2022 3:14 am
Forum: Engine Tech
Topic: Running oil cooler in scavenge return line
Replies: 4
Views: 155

Re: Running oil cooler in scavenge return line

What's the big gain of having the radiator down the back (I built a Monza Speedway car with the radiator for a passenger) but that was with methanol.

Sounds like a desperate move for weight distribution.

Why can't you use a water to oil unit in the bottom hose at the front of the vehicle ?
by Tom68
Mon Sep 26, 2022 10:58 pm
Forum: Engine Tech
Topic: What's better A timing chain setup or a gear drive setup
Replies: 11
Views: 411

Re: What's better A timing chain setup or a gear drive setup

ClassAct wrote: Mon Sep 26, 2022 10:31 pm

Do you have a link to that paper? The one I found tha I think was by Roush only tested a dual idler gear drive.
I have the paper somewhere, don't know if it's online.
by Tom68
Mon Sep 26, 2022 9:36 pm
Forum: Engine Tech
Topic: What's better A timing chain setup or a gear drive setup
Replies: 11
Views: 411

Re: What's better A timing chain setup or a gear drive setup

Roush tested the various cam drives, there's an SAE Paper on it.
Didn't test belts, rejected for low tensile strength.
HyVo type chain sucked up the least power from memory.
Paper would be mid to late 90's.
by Tom68
Mon Sep 26, 2022 7:16 pm
Forum: Engine Tech
Topic: Coolant recovery can or not ?
Replies: 7
Views: 384

Re: Coolant recovery can or not ?

The recovery tank on my 1975 Monte Carlo ( original ) is plastic . The lid is plastic which snaps on, with the hose attached leading into the tank below marked coolant level. The radiator cap is spring loaded. " sealed " may be the wrong word of choice, but it is capped. The little return valve in ...
by Tom68
Mon Sep 26, 2022 7:11 pm
Forum: Engine Tech
Topic: Camshaft lobe design by Billy Godbold
Replies: 31
Views: 1143

Re: Camshaft lobe design by Billy Godbold

Stan Weiss wrote: Mon Sep 26, 2022 1:15 pm
https://www.youtube.com/watch?v=K1DFrWcvTuc


The 0.050" duration people will not like it! :lol: 50 HP difference! :shock:

Stan
The 50 thou people that can accomodate 800 thou lift and 7/16" pushrods.
by Tom68
Mon Sep 26, 2022 3:44 am
Forum: Engine Tech
Topic: Larry's Soft Head
Replies: 75
Views: 40953

Re: Larry's Soft Head

Toluene has quite a good MON, RON rating: 112 and 124 respectively. With the math done you have to mix 84 % Toluene with 16 % n-Heptane (0 RON-rating) to get a 102 RON rating, which was necessary to pass the RON testing. See Honda's SAE article Glover, A. R., A. Yasuoka, I. R. Galliard, and Y. Mats...
by Tom68
Mon Sep 26, 2022 2:53 am
Forum: Engine Tech
Topic: What was Chevrolet thinking ?
Replies: 27
Views: 1069

Re: What was Chevrolet thinking ?

The above specs for 10185071 (ZZ4 cam also in x604 (current ZZ6) and CT400 and in defunct x603 crate (L98 aka x113 heads) --- those specs above are different than what I've been seeing for many years for 10185071 . All I've known are split on both duration & lift. Yer I've never seen the 235 cam be...
by Tom68
Sun Sep 25, 2022 5:51 pm
Forum: Engine Tech
Topic: What was Chevrolet thinking ?
Replies: 27
Views: 1069

Re: What was Chevrolet thinking ?

Iirc, the later 208/221 cam was used so they could offer the ZZ motors as an emissions legal package for 3rd gen Camaros. The earlier 235/235 cam wouldn't pass emissions. The ZZ4 was a really nice daily driver performance engine. The earlier setups was definitely lumpier and weak on bottom end torq...
by Tom68
Sun Sep 25, 2022 7:14 am
Forum: Engine Tech
Topic: What was Chevrolet thinking ?
Replies: 27
Views: 1069

Re: What was Chevrolet thinking ?

Rereading that I see there isn't an obvious question. I guess what I'm wondering is how did Chevrolet come up with two cams so different to do a similar job. Obviously one is bigger than the other....but like.....wow......Are we all to precious about how we choose a cam if they can throw these two o...