What to look for
#11
12-09-2005, 10:55 PM
RE: What to look for
ORIGINAL: Lee Willis
We never had any problems with our '98 un til we blew the motor up on maybe the 200th 1/4 mile pass, but then it was modified and producing close to 525 RWHP and lifting the front wheels. it was a great engine even if not as powerful as later models.
the block - thinner cylinder walls? Our block was still fine after the engine blew - we magnifluxed it and it was okay and we sold it to a guy that honed it 3 thousandths and it is still running in another, heavily modified car.
The heads? As far as i know there was no big difference until the Ls-6 heads: all LS1 stock heads are okay, but not really that good.
Things to look for:
1) the rear axle is the Achilles heel on F-bodies. check for leaks around the front seal on the differential, signs of leaks around the rear cover seal. Any noises. These are chronic problem area.
2) Manual Transmission: third gear tends to take abuse in cars that are heavily driven and is usually the first synchro/gear to go. When driving the M-6, check to see that it shifts easily (and fast) inbto third and ffourth. Assume that you face about $900, after you take the trans out of the car and cart it to the reapir shop, to repair it if you feel anything less than perfect action: once you feel resistance here, you have about two months left.
3) Does it have any mods? Check them carefully. Nothing wrong with a modded car (headers, etc.) just more likely to have been abused.
We never had any problems with our '98 un til we blew the motor up on maybe the 200th 1/4 mile pass, but then it was modified and producing close to 525 RWHP and lifting the front wheels. it was a great engine even if not as powerful as later models.
the block - thinner cylinder walls? Our block was still fine after the engine blew - we magnifluxed it and it was okay and we sold it to a guy that honed it 3 thousandths and it is still running in another, heavily modified car.
The heads? As far as i know there was no big difference until the Ls-6 heads: all LS1 stock heads are okay, but not really that good.
Things to look for:
1) the rear axle is the Achilles heel on F-bodies. check for leaks around the front seal on the differential, signs of leaks around the rear cover seal. Any noises. These are chronic problem area.
2) Manual Transmission: third gear tends to take abuse in cars that are heavily driven and is usually the first synchro/gear to go. When driving the M-6, check to see that it shifts easily (and fast) inbto third and ffourth. Assume that you face about $900, after you take the trans out of the car and cart it to the reapir shop, to repair it if you feel anything less than perfect action: once you feel resistance here, you have about two months left.
3) Does it have any mods? Check them carefully. Nothing wrong with a modded car (headers, etc.) just more likely to have been abused.
#12
12-10-2005, 03:21 PM
RE: What to look for
[/quote]
97+98 heads had perimeter valve cover bolts and are rumored to not flow quite as well as the later castings.
[/quote]
Rumored maybe but we never saw any real difference in performance. Our '98, and a friend's '98 Firebird, were just awesome up against later cars with similar mods - there just wasn't any difference in performance -- all of us with stoc k bloksd were running in the high 11s N/A, mid and low with NOS.
But still, no LS1 head is that good. No offense to anyone who has them, but I can see not reason to put any LS1 heads ON a car - once they come off, they should be replaced with something that really breaths: if you're doing that much work find the money for better heads. A stock LS6 at least, but realize they aren't even that good anymore (stock heads for the Chrysler hemi SRT outflow them) or an aftermarket ported LS6, AFR, etc. Or if budget necessary, ported LS1. But something that flows at least 300, hopefully over 330.
We actually used the LS1 heads that came off the original engine, when we tore it down, as boat anchors -- you hear the joke all the time about an old engine being worth for nothing but a boat anchor, and for fun we actually took one and made it the anchor on my son's boat. (It works really well, too, both as an anchor as a joke).
#13
12-10-2005, 06:26 PM
RE: What to look for
The heads are why the LS1 makes so much power, they are some of the best production heads Chevy has ever made. Now of course aftermarket ones are going to be better, but look at all the cam only cars that run deep 11's and have never had the heads off. I don't think the LS1 head is junk, but it really depends on what your goals are. Who makes a true aftermarket casting besides AFR? Most heads are either 5.7 or 5.3 heads that have been CNC ported, I know Patriot does this as well as several other companies.
#14
12-10-2005, 11:53 PM
RE: What to look for
Patriot makes good versions, that's for sure. I have a set of their stage III (with the 2.08" valves) LS6 heads on my vette. Flowed 335-340 from them, had them ported and polished some more by Justin Engineering - flow tested at 347. AFR small ports were available when I had the engine built but not the big ports then: we did get them for the Camaro though.
But I would not put stock LS1 heads back ona car if I had to take them off for any reason. Even bargain LS1 ported heads are really good now.
But I would not put stock LS1 heads back ona car if I had to take them off for any reason. Even bargain LS1 ported heads are really good now.
#15
12-12-2005, 08:06 PM
RE: What to look for
ORIGINAL: Lee Willis
We never had any problems with our '98 un til we blew the motor up on maybe the 200th 1/4 mile pass, but then it was modified and producing close to 525 RWHP and lifting the front wheels. it was a great engine even if not as powerful as later models.
the block - thinner cylinder walls? Our block was still fine after the engine blew - we magnifluxed it and it was okay and we sold it to a guy that honed it 3 thousandths and it is still running in another, heavily modified car.
The heads? As far as i know there was no big difference until the Ls-6 heads: all LS1 stock heads are okay, but not really that good.
Things to look for:
1) the rear axle is the Achilles heel on F-bodies. check for leaks around the front seal on the differential, signs of leaks around the rear cover seal. Any noises. These are chronic problem area.
2) Manual Transmission: third gear tends to take abuse in cars that are heavily driven and is usually the first synchro/gear to go. When driving the M-6, check to see that it shifts easily (and fast) inbto third and ffourth. Assume that you face about $900, after you take the trans out of the car and cart it to the reapir shop, to repair it if you feel anything less than perfect action: once you feel resistance here, you have about two months left.
3) Does it have any mods? Check them carefully. Nothing wrong with a modded car (headers, etc.) just more likely to have been abused.
We never had any problems with our '98 un til we blew the motor up on maybe the 200th 1/4 mile pass, but then it was modified and producing close to 525 RWHP and lifting the front wheels. it was a great engine even if not as powerful as later models.
the block - thinner cylinder walls? Our block was still fine after the engine blew - we magnifluxed it and it was okay and we sold it to a guy that honed it 3 thousandths and it is still running in another, heavily modified car.
The heads? As far as i know there was no big difference until the Ls-6 heads: all LS1 stock heads are okay, but not really that good.
Things to look for:
1) the rear axle is the Achilles heel on F-bodies. check for leaks around the front seal on the differential, signs of leaks around the rear cover seal. Any noises. These are chronic problem area.
2) Manual Transmission: third gear tends to take abuse in cars that are heavily driven and is usually the first synchro/gear to go. When driving the M-6, check to see that it shifts easily (and fast) inbto third and ffourth. Assume that you face about $900, after you take the trans out of the car and cart it to the reapir shop, to repair it if you feel anything less than perfect action: once you feel resistance here, you have about two months left.
3) Does it have any mods? Check them carefully. Nothing wrong with a modded car (headers, etc.) just more likely to have been abused.
#16
12-13-2005, 12:11 AM
RE: What to look for
There is no LS aluminum engine I would bother boring at all. A new standard block is cheap. I don't know what the LS7 block costs, but the C5R was expensive but worth it.
Anymore, I'd go for the cast iron anyway. The 408 we have in the Camaro is 90 lbs heavier but still a very light engine overall. Its still light and strong as the ****ens. We bored it 30 over and have no problems, and we've had friends who pushed to 60 over in the iron block and had no problems (we've also had ones who did).
Anymore, I'd go for the cast iron anyway. The 408 we have in the Camaro is 90 lbs heavier but still a very light engine overall. Its still light and strong as the ****ens. We bored it 30 over and have no problems, and we've had friends who pushed to 60 over in the iron block and had no problems (we've also had ones who did).
