Hmmm, decision time....

[Guest]

Alright well I pulled the heads off of James (1985 GMC Jimmy), that has been loosely bolted on for about a year or so now, probably longer, just to keep it somewhat sealed up, There were no spark plugs in teh heads, I know I'm a dumbass.

Now, I was expecting at least some light rust on the cylinder walls, since I didn't coat them in anything before I moved it to a previous location and then to where it is now, at the previous location it sat outside for about 6 months. Overall it's not too bad and even the cylinder that is bad IMO, could probably be cleaned up with a light hone or maybe just some elbow grease and a rag, but it looks worse than that right now, you know that black corrosion that forms, yeah it looks like that.

Now here are my two choices:
I have another genI (2. block that I could have bored and prepped and basically put it back together the way I was planning on putting this one back together, all new bearings etc, etc.

Or I could use a 3400 block, re-drill the starter holes (will have to make a jig for that), and a new driver side mount, along with a modified oil pan and maybe crossmember, I believe I could do it with just a modified oil pan.

GenI block would allow me to retain my 260-2 bumpstick, which works very well, keep my current pistons (Federal Mogul Hyper Eutectic FWD stock replacement 3.1 pistons .030" overbore). It will bolt right in, with out ANY worries.

GenIII block would give me full roller bumpstick, better oiling, and more displacement, but cam selection is next to nil, especially for a turbo grind, more actual work getting it in there, and would need new pistons, I don't trust the stock cast pistons, would at least like hyper eutectics, since the ones in the current block still look almost new after 20 000+ KMs of HARD abuse.

I had intended to keep this simple if it came to a decsion like this and keep the block the way it was as a genI block, for ease of install and current parts swap-ability, but I'm at a crossroads, where I could possibly gain an easy 25 to 50 HP, just by going the 3400 route, if not more.

What would you do?

[sharkey]

i wouldnt consider the roller cam to be a major deciding factor in it, the power gains you may have from a roller cam likley wouldnt warrent the extra work getting the motor in there.

i myself would look for a 3.4l f-body short block to get the extra displacment and build that up with some custom pistons. going with a 3.4l opens up the option for the 3500 heads aswell.

[treeZ24]

if you're not keeping the rev's up i wouldnt consider the roller cam as being such a large factor just as steve said. especially since you can get solid rollers for the gen2 block BUT the priority oiling is nice feature to have from the gen 3 block.

just for ease of install i would almost go back with the gen1 block, especially since you have it already and the machine work really isn't that expensive. the huper pistons should work OK for mid boost, running 94 and keeping the DCR within reason. i dont see why you couldnt make more power with that setup.

on the other hand, you could make a real street thumper engine with that 3.4 block and 3500 heads. it would just take more time and the nice weather is already coming.. first street legal drags were tonight and it was a gorgeous night for em

[Guest]

Other people have suggested the F-body 3.4 block, but it's not an option for the following reasons:

-I don't have one
-Last time I looked into getting one it would have cost me about $1000, only could find a long block and would only end up using the block it self. :?

I'm looking at using what I already own, that being a 2.8 block, or a 3400 block, I have 2 3400 blocks, and one 2.8 block.

Not doing a 3500 top end, since I don't own any, and the 3500 heads would be saved for a future planned project anyway.

I'm also thinking that since I would be teh first to dthis swap I could document it and sell the conversion parts, much like the FWD 3400 swap into a J/L-body.

Still undecided overall.

[treeZ24]

go with the largest motor you have. might be a bit more work but that doesnt seem like a problem for you.

besides then i can use the jig for redrilling the starter lol

[ignoreance]

If you want I could loan you mine just as long as your promise to mail it back. You pay me to and from mail charges. Its got all the drills and everything. Thats the Jig I'm talking about

[ForcedFirebird]

If you are asking my opinion, I think you should sell the three blocks to get a 3.4 so you can sell me your DIS setup that your Grandpa made, lmao!

[Guest]

If you are asking my opinion, I think you should sell the three blocks to get a 3.4 so you can sell me your DIS setup that your Grandpa made, lmao!

LOL, I've thought about that, but I think I'll still hang on to it, even if I'm not using it, I like to keep the prototypes.

I need to keep at least 1 of the 3400 blocks for a future planned project, also a RWD project.

I'm REALLY leaning towards the 3400, even with the extra expense of pistons, and new bearings through out.

I'll probably just run a stock cam.

[ForcedFirebird]

You know you should get someone to write a CNC program for those. I have a friend with a shop, if you could disclose some measurements, I might be able to get them cheap-cheap (most parts cost me less than $20)

[Guest]

You know you should get someone to write a CNC program for those. I have a friend with a shop, if you could disclose some measurements, I might be able to get them cheap-cheap (most parts cost me less than $20)

I already have someone laser cutting my mounts for me. Saves SO much time over when I was hand cutting them.

I'll end up doing the same with these mounts.

[ForcedFirebird]

I was talking about the DIS...

[Guest]

I was talking about the DIS...

I know you were, the trigger wheel is the first one, hence Prototype.

Besides even if I use the 3400 I'll probably still use the trigger wheel, to give me adjustable base timing.

[geoffinbc]

I disagree with people saying roller cams are not a big deal. But today they really are..

First off you dont need an aftermarket cam for what you are doing. Just get a ragrind. The stock LSA lends itself well to a turbo grind so only lift and duration need to be modified.

Second with the problems everyone is having with flat tappet cams failing latley I would be very cautious when considering them. But these problems are really with the new oils. So it can be avoided.

Lastly of course is the power and efficiency of a roller cam. Which at any rpm is a real nice advantage.

Lastly, I have been comparing SBC, 4.3L and Gen I lifters and I believe a roller cam can easily be installed in a Gen I engine. 4.3L engines DO NOT use priority main oiling. They have an indentical oiling system to a 60* V6 with the larger left hand lifter galley feeding the cam and then the crank. Yet they use identical lifters to a small block. I used to believe that the 60* engine would starve the crank of oil when using roller lifters. But after comparing the lifters to each other I see no reason why this would happen. I think this asumption started because GM changed the oiling at the same time they added a roller cam to the 660. But the two changes may be completly unrelated. I believed this theory but never investigated it myself. But my next engine I am going to be trying a GenI block with a Hyd roller cam, because I see no reason it can't be done.

[rvbilly]

Flat Tappet Cam

Hi to all , The hydraulic flat tappet cam I recently got I was told by the supplier to go to GM and get this $10 can of oil additive that replaces the ZINK in the oil for Break-in periods , he said it was necessary so the cam and related engine components did not wear excessavly during break-in, I forget what it was called.. Bill

[sleeperred90tgp]

I disagree with people saying roller cams are not a big deal. But today they really are..

First off you dont need an aftermarket cam for what you are doing. Just get a ragrind. The stock LSA lends itself well to a turbo grind so only lift and duration need to be modified.

Second with the problems everyone is having with flat tappet cams failing latley I would be very cautious when considering them. But these problems are really with the new oils. So it can be avoided.

Lastly of course is the power and efficiency of a roller cam. Which at any rpm is a real nice advantage.

Lastly, I have been comparing SBC, 4.3L and Gen I lifters and I believe a roller cam can easily be installed in a Gen I engine. 4.3L engines DO NOT use priority main oiling. They have an indentical oiling system to a 60* V6 with the larger left hand lifter galley feeding the cam and then the crank. Yet they use identical lifters to a small block. I used to believe that the 60* engine would starve the crank of oil when using roller lifters. But after comparing the lifters to each other I see no reason why this would happen. I think this asumption started because GM changed the oiling at the same time they added a roller cam to the 660. But the two changes may be completly unrelated. I believed this theory but never investigated it myself. But my next engine I am going to be trying a GenI block with a Hyd roller cam, because I see no reason it can't be done.

Your correct about the roller cam and lifters. They work just fine in a 3.1 vin t or v block. I have been running one for about 2 years. Not a peep out of it.

This stock roller kicked ass on all of the aftermarked cams that I have had in my motor buy about .5 second. Ran a 13.58 last year. (2002 impalla 3400 heads and cam. That was good enough for the fastest TGP so I haven't really leaned on it in over a year.

Do it, if you want to know something email me cause this is the first time I have been on here in months.

With a roller you don't have to worry about these new oils that don't have the flat tappet chemicals in them.

For you flat tappet guys get shell rotella diesel oil. It's got the stuff you want.

Good luck your cam install, you will be satisfied.

Jud.