Putting a Caprice engine (L05-7) into a 92 g30 van (has L80e trans)

[Erik the Awful]

My first thought is that the roller lifter pushrods are shorter than the flat-tappet pushrods. What combination of lifters and pushrods are you using?

 

[Danboquist]

My first thought is that the roller lifter pushrods are shorter than the flat-tappet pushrods. What combination of lifters and pushrods are you using?

The pushrods are the stock (I assume) that came out of the engine (Flat tappet lifters). The lifters are rollers. I had heard comments that the roller lifters were taller (to accomodate the dog bones), but the seats were recessed to match the flat tappets. Obviously something doesn't add up with that.. I need to research and compare the numbers I guess.

Some guy from a Hot Rod forum says.. "The stock flat tappet pushrods are 7.800". OEM roller cam uses 7.200" pushrod. "

I just made a Redneck pushrod length checker to get a rough idea of the difference between the length of the existing pushrod and the approximate length of a pushrod needed to get me in the center of the spring. The rough difference is ~.62 in.
So the Hot Rod guy says 7.8-7.2=.6 " and my test shows .62" (see below).
So far it seems that the difference is caused by the roller lifters being longer..

 

[Schurkey]

Two issues:

1) Not paying enough attention, I replaced the double timing chain setup with a new single timing chain. Could this be a big problem?

It is no problem at all. The single-row chains are proving to be as reliable as the double-row.

2) With the heads on and bolts in hand tight, and the engine at TDC, I threw in a pushrod that came out of the engine (flat tappet setup) and it looks way long.

Yes, the pushrods for the OEM roller lifters are shorter than the flat-tappet pushrods due to the extra height of the roller lifter.

IF you're using pushrod guideplates, the pushrods MUST be hardened. If you're using self-aligning rockers, or cylinder heads that guide the pushrods on cast-iron "oval" pushrod holes, non-hardened pushrods are acceptable.

 

[Danboquist]

It is no problem at all. The single-row chains are proving to be as reliable as the double-row.


Yes, the pushrods for the OEM roller lifters are shorter than the flat-tappet pushrods due to the extra height of the roller lifter.

IF you're using pushrod guideplates, the pushrods MUST be hardened. If you're using self-aligning rockers, or cylinder heads that guide the pushrods on cast-iron "oval" pushrod holes, non-hardened pushrods are acceptable.

I sent a query to Daniel at Powell Machine (check him out on YouTube) and this is what he said:
====>>>> From me:
Changing my 92 Chevy 350 Gen 1 over from flat tappet to roller cam I'm seeing that the old pushrods are too long (~ 7.8).
It is looking like the new pushrod length will be around ~7.2 (.6 or so difference). I've ordered a pushrod length checker to get a good measurement.
Do you have pushrods around 7.2 in length?

=====>>>>> From Daniel Powell:
7.2 Is the correct length. We have those in stock. $101.99

 

[Schurkey]

www.summitracing.com/parts/SUM-G6406

Summit Racing SUM-G6406 Summit Racing™ Pushrods | Summit Racing

Free Shipping - Summit Racing™ Pushrods with qualifying orders of $109. Shop Pushrods, Valvetrain at Summit Racing.

www.summitracing.com

Bought these a month or two ago. They'll be going into my "stroker" 354+, someday when I work up the ambition to assemble the thing.

That engine is a pretty-ordinary 350, but with an offset-ground crank. .040 extra stroke fixes my quench issue, as the piston rises an extra .020. (and goes down an extra .020, so I have to watch the piston-to-counterweight clearance.)

 

[Erik the Awful]

Do you have pushrods around 7.2 in length?

Since I used Vortec roller bits, I just used the Vortec pushrods and self-aligning rockers.

 

[Danboquist]

Different size thermostats.. weird problem
I have two intakes with different size thermostat holes..

10093015..... approx 59mm
14102182......approx 54mm

I'll be using the 015 intake.
Is the size difference caused by the need for a rubber sealing ring on the larger hole?

 

[L31MaxExpress]

Different size thermostats.. weird problem
I have two intakes with different size thermostat holes..

10093015..... approx 59mm
14102182......approx 54mm

I'll be using the 015 intake.
Is the size difference caused by the need for a rubber sealing ring on the larger hole?

The larger opening was machined to use the oring.

 

[Danboquist]

The larger opening was machined to use the oring.

First thought is that I have to buy one of those AC Delco thermostats with the rubber ring.

 

[Danboquist]

This one scares me.. broken accessory bolts..
This engine had an older one-piece accessory mount, which managed to break off two of the accessory bolts in the block. Long story..

The mounts that I'm going to use are the two piece aluminum accessory mounts.

Of the two bolts that were broken off I only need the upper one (I managed to break off an extractor in the bottom one.. glad that I don't have to deal with that).

Now I'm left with this... I need to preserve these threads.. should I take it to a machine shop or mechanic shop to finish getting this out? I can't mess this up.