Lt1 top end overhaul

**JOATMON** · 02-13-2018, 10:52 AM

Take notice of the rear cylinder combustion chambers. Oil build up= heavy deposits.

**JOATMON** · 02-13-2018, 04:22 PM

In addition to being the wrong intake gaskets, they didn't have any sealant at all, they were installed dry. The upper intake was oil fouled too from a PCV valve that was sucking oil. The PCV system was not set up correctly neither. The hose that normally would run between the valve cover and the throttle body was gone and they were running a breather on the valve cover. This setup was allowing un-metered air flow into the throttle body.(The stock setup is using airflow that has been measured by the MAF sensor)

**JOATMON** · 02-13-2018, 04:50 PM

I bought new valve guides and new valve springs. The valve springs that were on it were way too stiff for a hydraulic roller. Brought the heads to a friend to do the guides and valve job and got a disturbing call a couple of weeks later. He had a problem pressing the guides out of one head, the valve guide bosses cracked on a bunch of the guides. It looked as though it might be okay with some grinding done on the cracked area, but one boss broke so badly that there was only about 3/4" of material supporting the guide. The guides came out of the other head with no cracking issues. We decided to buy one new bare head. He took responsibility for the damage, he didn't charge me anything for all of the work and he gave me $400 cash towards the cost of a new bare head. Good Man in my book. Had to wait near two months for the new head(custom order).

**JOATMON** · 02-13-2018, 05:00 PM

Broken head, new headAttachment 38212 Attachment 38213 Attachment 38214
IMG_1314.JPG
IMG_1316 (2).JPG
IMG_0127.JPG

**JOATMON** · 02-13-2018, 05:12 PM

It appears that the factory presses in the valve guides, then does the CNC port work. The guide bosses and the bottom of the guides are cut down pencil shaped, so I can see where they could easily break when replacing guides.

**JOATMON** · 02-13-2018, 05:23 PM

I don't have a pic of the piston tops but they were extremely caked with carbon from all the oil burning. It was a big chore to clean them and I got sick from breathing all the brake cleaner and B12 Chemtool I used to clean them. After I got feeling better a few weeks later, I used a respirator to finish the cleaning.
IMG_0152.JPG IMG_0153.JPG

**JOATMON** · 02-13-2018, 05:45 PM

I'm not sure why my photos came up as an attachment in post #14???
Now on to the valve train. I don't have a photo but I found the lifter spider had several bent fingers. I'm extremely lucky that the dogbones didn't come off the lifters. After doing some research and some measuring to verify, it appears that when you get above approx. .350 lobe lift you are gambling with the dogbone and spider setup. The flats on the lifters that locate the dogbone come very close to hitting at max lift and very close to dropping out of the dogbones on the base circle of the cam. Howards and maybe others make replacement lifters that have a longer flat area to help with this, but I opted to buy tie-bar lifters. IMG_0108.JPG

**JOATMON** · 02-13-2018, 05:51 PM

Here's where I mocked up the valves with check springs to figure out proper pushrod length. It gets much deeper as I gained my PHD in rocker arm geometry so I'll stop here and continue later.IMG_0106.JPG

**fullforce** · 02-14-2018, 05:55 AM

Wow, very nice build...or RE build!

**JOATMON** · 02-14-2018, 09:12 AM

I ain't gonna lie, the rocker arm setup confused the hell out of me. I was attempting to get the rockers up and off the valve spring retainers. After inspecting the Crane Gold rockers there didn't appear to be anything wrong with them. I got it in my head that because the AFR heads use plus .100" valves that I simply needed a longer push rod to get the rockers up. The reason for longer valves is to provide space for a taller spring to allow a real high lift cam, for anyone wondering why. I've done other small block Chevys with stock type heads and valve lengths and never had any issues with rocker clearance or alignment. These heads in addition to the longer valves also have the port locations somewhat changed and the valve layout is spread out to allow bigger valves.(2.08/1.60)