Buck69
Full Access Member
- Joined
- Feb 2, 2023
- Posts
- 227
- Reaction score
- 293
- Location
- Northern British Columbia
- First Name
- John
- Truck Year
- 1986
- Truck Model
- D30 CUCV
- Engine Size
- 6.2 (removed)
Interesting and I appreciate the time you spent writing this all out. Thanks.Here's my cam using a Jasper Built Marine engine, circa 1994 GM Cast Iron Block, High Compression Forged Pistons, cast GM Performance Crank, Short Block with Vortec Heads and a 7116 intake and stock TBI, (for now)... 670-680 cfm TBI sooner or later...
Comp 12-304-4 Flat Tappet... .406 / .406 252 / 252 13.0 ATDC
Comp Extreme Energy Lifters... .015" stainless head gaskets, Pistons were .020" from the top deck. AFR non-stretch head bolts.
I wanted to go roller but it was several thousand dollars more for quality parts...
The forged pistons cover you in case of detonation... and allow you to go carb, TBI, EFI, (nitrous if your greedy)... whatever... it will be built to last with Moly rings... no early cracking from lube issues... No need for a forged crank or forged rods.... Skirted pistons...
Keep the lift within reason, and it will outlast any low compression engine and gain efficiency. You'll have to run zinc and high octane (no ethanol ever) with a boost additive every tank full 91-93 octane. The results should outlast your low compression engine on pump gas with corn...
The idea is to over protect for detonation at any point in the engine's life. It happens due to sensor failure, engine wear, improper timing... etc... Moly rings will last a very long time without the giggle juice on these specs... 300-400,000 miles or more... The high compression makes the most of the lower quality fuel injection's capabilities. My heads are 64cc, stainless valves, ported mildly to the gasket shapes on both sides of the heads. 1-5/8" primaries to 2-1/2" collectors using Sanderson Stainless Shorty headers.
If you do not defend for ping and detonation during the engine's life cycle it will kill your low compression engine when it happens by accident or improper tuning issues. Unfortunately, these can and will occur with a TBI engine, when the knock sensor fails or the engine is using poor quality fuel.
It's not bullet proof, just much better at handling the inevitable... Strong internals and low to moderate cam = long life engine.
I used a Melling high volume oil pump, not high pressure... you can probably get by with a regular volume pump as well.
The best solution is buying a Dart Block with primary oiling... this is probably the next best solution, in my opinion.
Hope this clears up the logic and handles the safety limits: spending the least, to achieve the most... without breaking anything.
Compression can be your friend... just don't push it with a huge cam or 1.6:1 rockers... you do not ever need them.
Start with the camshaft... then build outwards... Not the other way around...
I think you missed my vague point though. I live in northern BC and the price of premium fuel here over $2/liter. It is also not always available in some of the remote areas I travel to.
How do you come up with several thousand more for a roller cam block?
I am a diesel mechanic by trade but don't mind tinkering on my own gassers. The engine I was planning on putting in this truck was for the temporary purpose of only trying a 5.7 with this truck. It was a build I did for my ocean boat last spring. All in including machine work was $2000 at best with a 10243880 4 bolt roller cam block. It was out of a '97 TBI suburban in the junkyard. I had it bored .020 over with 1/2 dished hypereutectic pistons with ARP head and main cap screws. Nothing fancy. It is rated at 300hp @ 4800 with an Edelbrock carb, Mercruiser cam and Thunderbolt V ignition system. The cam is just a modified GM performance cam that is somewhat mild to avoid water reversion through the exhaust. Can swap it out to whatever and stay with 87 at the pumps.
Not looking to get into an engine build debate here, just sharing my plans.