454 TBI rebuild

cbr600rx7 · 06-26-2009, 10:12 AM

This is in a 1990 1 ton work truck that has been one of the best running trucks i have ever owned. The truck has all most no rust and even the AC works with over 266,000 miles one her. Now for the issue she started burning oil in the number 8 cylinder around 20,000 miles ago. Nothing too bad as long as the truck is moving. Its when the truck sits for a few days or idles for 5 or 10 minutes that it start smoking. Of course once you start moving it goes away. I figure its probaly the rings giving out. The one other thing is the truck is down on power a small bit. She will still pulls just not what she ussed to.

So here is where i need help. I had been thinking about rebuilding the old girl. With the engine having so many miles i wanted to go a head and do a small over bore .30 over and a nice torque cam. The other thing i face is to keep the TBI or go to a carb set up. The TBI sucks at flowing up top but not sure how hard it would be to convert over to a carb.

Any way this is more of a short rant. Any one with experence or advice fill free to drop in.

cbr600rx7 · 06-26-2009, 08:58 PM

Ok talked to my shop today. Looks like around 700 for labor that includes punching it out .30 over for the new pistons. For CR i want to bump it up from 8.7-1 up to 9.5-1.j

We are going over to carb but i could use some help picking a manifold, carb, and cam for this thing.

Keep in mind its a pulling truck it is going to be a premium fuel truck to help with the higher CR.

cbr600rx7 · 06-26-2009, 09:32 PM

So this is the list that i have come up with as far as the rebuild. Keep in mind its a 266,000 mile truck.
Oil pump
Water pump
Intake manifold (still need help)
Carb (Still need help) 670 or 770????????
Towing cam (voodoo hyd 256/262 112 LSA)
Valve springs
rockers
timing chain kit

Updated...

raped 95Z · 06-27-2009, 07:09 AM

rings, bearings, valve seals, if your doing a cam, get the cam anf lifter kit. umm and its 6:30am i cant think of anything else off the top of my head

speedy55 · 06-28-2009, 08:57 PM

your oil burning problem sounds like a valve seal to me. I would use an edelbrock performer dual plane manifold.

cbr600rx7 · 06-28-2009, 11:09 PM

Might be. Thanks for the intake tip i plan on having the heads checked out and freshend up a bit why they are off.

Rocko350 · 07-01-2009, 06:09 AM

Keep the tbi, convert to a single plane intake with adapter plate. One of the extreme 4x4 grinds would wake a stockish motor up nicely. A good set of pushrods, and a set of headers. Your choice on the headers, but upgrade the o2 sensor to a 3 wire and have it tuned. No mail order tune will be even close. Go over to www.thirdgen.org and check out what those guys are doing. Ive done several big block caprice swaps with tbi, and am in the middle of a big block into an LT powered car using the Lt pcm to control it. by the way, most of the guys iver there that are the experts on TBI aren't even thirdgen camaro owners. Most have trucks, one guy specializes in vans. Keep the fuel injection!

cbr600rx7 · 07-01-2009, 12:56 PM

Thanks for the link. That would be perfect.

cbr600rx7 · 07-01-2009, 12:59 PM

I am still trying to find out if it is the rings or the valves that are leaking. I considered doing a leak test but im not sure if it would do any good. We know it is burning oil in the #8 cylinder but all the other plugs look clean.

FiredUpZ28 · 07-01-2009, 02:46 PM

if it blows smoke after sitting for a while, its the valve seals. Do a cylinder leakage test it'll tell you right away if its the rings or not. Compression check with oil in the cylinder will as well. If you have better compression with oil in the cylinder then its the rings.

cbr600rx7 · 07-01-2009, 07:17 PM

It normaly starts clean and drives clean. But after it sits and ideals for a bit it starts smoking. The longer it sits the more it smokes. Then you drive it a bit and it clears right up.